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Horie F, Ando R, Sekimoto K, Nguyet VTA, Izawa S. Yeast Hsp78 plays an essential role in adapting to severe ethanol stress via mild ethanol stress pretreatment in mitochondrial protein quality control. Biochim Biophys Acta Gen Subj 2025; 1869:130804. [PMID: 40187374 DOI: 10.1016/j.bbagen.2025.130804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2025] [Revised: 03/28/2025] [Accepted: 04/02/2025] [Indexed: 04/07/2025]
Abstract
Severe ethanol stress (10 % v/v) causes the denaturation and aggregation of certain mitochondrial proteins, such as aconitase (Aco1), forming the deposits of unfolded mitochondrial proteins (DUMPs) in the budding yeast Saccharomyces cerevisiae. Pre-exposing yeast cells to mild stress often induces adaptation to subsequent severe stress. However, whether pre-exposing yeast cells to mild ethanol stress mitigates mitochondrial protein aggregation remains unclear. Therefore, in this study, we examined the effects of pre-exposing yeast cells to mild ethanol stress on the yeast mitochondrial protein quality control (mtPQC) system under severe ethanol stress. Pretreatment with 6 % (v/v) ethanol significantly mitigated the formation of DUMPs and Aco1 aggregates under subsequent 10 % ethanol stress in wild-type cells but not in hsp78∆ and mdj1∆ cells. Pretreatment with 6 % ethanol increased the protein levels of mtPQC-related factors, Hsp78, Mdj1, and Hsp10; however, hsp78∆ cells showed significantly lower levels of Ssc1 (mtHsp70) and its co-chaperone Mdj1 than wild-type cells. Moreover, intracellular reactive oxygen species levels and the frequency of respiration-deficient mutants under 10 % ethanol stress were reduced after pretreatment with 6 % ethanol in wild-type cells but not in hsp78∆ cells. Overall, this study demonstrated that pre-exposing yeast cells to mild ethanol stress mitigated ethanol-induced mitochondrial damage by activating the mtPQC system, including HSP78 expression, providing novel insights into the effects of ethanol stress on mitochondria and the corresponding responses in yeast.
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Affiliation(s)
- Fuko Horie
- Laboratory of Microbial Technology, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Ryoko Ando
- Laboratory of Microbial Technology, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Koharu Sekimoto
- Laboratory of Microbial Technology, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Vo Thi Anh Nguyet
- Laboratory of Microbial Technology, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Shingo Izawa
- Laboratory of Microbial Technology, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
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2
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Wickner RB, Hayashi Y, Edskes HK. Anti-Prion Systems in Saccharomyces cerevisiae. J Neurochem 2025; 169:e70045. [PMID: 40130511 PMCID: PMC11934224 DOI: 10.1111/jnc.70045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2025] [Revised: 02/24/2025] [Accepted: 03/09/2025] [Indexed: 03/26/2025]
Abstract
[PSI+] is a prion (infectious protein) of Sup35p, a subunit of the translation termination factor, and [URE3] is a prion of Ure2p, a mediator of nitrogen catabolite repression. Here, we trace the history of these prions and describe the array of anti-prion systems in S. cerevisiae. These systems work together to block prion infection, prion generation, prion propagation, prion segregation, and the lethal (and near-lethal) effects of most variants of these prions. Each system lowers the appearance of prions 2- to 15-fold, but together, ribosome-associated chaperones, the Hsp104 disaggregase, and the Sup35p-binding Upf proteins lower the frequency of [PSI+] appearance by ~5000-fold. [PSI+] variants can be categorized by their sensitivity to the various anti-prion systems, with the majority of prion isolates sensitive to all three of the above-mentioned systems. Yeast prions have been used to screen for human anti-prion proteins, and five of the Bag protein family members each have such activity. We suggest that manipulation of human anti-prion systems may be useful in preventing or treating some of the many human amyloidoses currently found to be prions with the same amyloid architecture as the yeast prions.
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Affiliation(s)
- Reed B. Wickner
- Laboratory of Biochemistry and GeneticsNational Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaMarylandUSA
| | - Yuho Hayashi
- Laboratory of Biochemistry and GeneticsNational Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaMarylandUSA
| | - Herman K. Edskes
- Laboratory of Biochemistry and GeneticsNational Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaMarylandUSA
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3
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Zheng L, Zhang Q, Wang C, Wang Z, Gao J, Zhang R, Shi Y, Zheng X. The heat shock factor HSFB1 coordinates plant growth and drought tolerance in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2025; 121:e17258. [PMID: 39918871 DOI: 10.1111/tpj.17258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/05/2024] [Accepted: 12/26/2024] [Indexed: 02/09/2025]
Abstract
Plants are constantly challenged by a diversity of abiotic stressors, and growth arrest is a common plant response aimed at enhancing stress tolerance. Because of this growth/stress tolerance antagonism, plants must finely modulate their growth and responses to environmental stimuli. Here, we demonstrate that HSFB1, a heat shock transcription factor, plays a critical role in the coordination of plant growth and drought stress responses in Arabidopsis thaliana. First, we found that HSFB1 negatively regulates plant growth and development under normal conditions and that HSFB1 expression is enhanced under drought stress. Conversely, the loss-of-function mutant hsfb1 exhibited increased plant growth and reduced drought stress tolerance compared with the wild-type. Consistently, overexpression of HSFB1 suppressed plant growth and enhanced drought stress tolerance. Subsequently, via chromatin immunoprecipitation sequencing, RNA sequencing, and transient expression assays, we screened and identified the heat shock protein 101 (HSP101) gene as a direct transcriptional target of HSFB1. Genetic analysis suggested that HSP101 functions downstream of HSFB1 to positively regulate drought tolerance in plants. Furthermore, we found that HSFB1 physically interacts with the eukaryotic translation initiation factor eIF3G1, and this interaction appears to be further enhanced under drought stress. Notably, the mutation of eif3g1 increased the severity of drought-induced growth inhibition in the hsfb1 mutant, and eIF3G1 enhanced the transcriptional activation of HSFB1 on the HSP101 promoter under drought stress. Altogether, our findings highlight HSFB1 as a key regulator coordinating plant growth and drought stress responses in Arabidopsis.
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Affiliation(s)
- Lanjie Zheng
- State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou, 450046, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
| | - Qianlong Zhang
- State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou, 450046, China
| | - Chen Wang
- State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou, 450046, China
| | - Zhongbao Wang
- State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou, 450046, China
| | - Jie Gao
- State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou, 450046, China
| | - Runcong Zhang
- State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou, 450046, China
| | - Yong Shi
- State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou, 450046, China
| | - Xu Zheng
- State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou, 450046, China
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China
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4
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Kaushik P, Herrmann JM, Hansen KG. MitoStores: stress-induced aggregation of mitochondrial proteins. Biol Chem 2025:hsz-2024-0148. [PMID: 39828945 DOI: 10.1515/hsz-2024-0148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2024] [Accepted: 12/19/2024] [Indexed: 01/22/2025]
Abstract
Most mitochondrial proteins are synthesized in the cytosol and post-translationally imported into mitochondria. If the rate of protein synthesis exceeds the capacity of the mitochondrial import machinery, precursor proteins can transiently accumulate in the cytosol. The cytosolic accumulation of mitochondrial precursors jeopardizes cellular protein homeostasis (proteostasis) and can be the cause of diseases. In order to prevent these toxic effects, most non-imported precursors are rapidly degraded by the ubiquitin-proteasome system. However, cells employ a second layer of defense which is the facilitated sequestration of mitochondrial precursor proteins in transient protein aggregates. The formation of such structures is triggered by nucleation factors such as small heat shock proteins. Disaggregases and chaperones can liberate precursors from cytosolic aggregates to pass them on to the mitochondrial import machinery or, under persistent stress conditions, to the proteasome for degradation. Owing to their role as transient buffering systems, these aggregates were referred to as MitoStores. This review articles provides a general overview about the MitoStore concept and the early stages in mitochondrial protein biogenesis in yeast and, in cases where aspects differ, in mammalian cells.
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Affiliation(s)
- Pragya Kaushik
- Cell Biology, 26562 RPTU University of Kaiserslautern , Erwin-Schrödinger-Strasse 13, D-67663 Kaiserslautern, Germany
| | - Johannes M Herrmann
- Cell Biology, 26562 RPTU University of Kaiserslautern , Erwin-Schrödinger-Strasse 13, D-67663 Kaiserslautern, Germany
| | - Katja G Hansen
- Cell Biology, 26562 RPTU University of Kaiserslautern , Erwin-Schrödinger-Strasse 13, D-67663 Kaiserslautern, Germany
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5
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Ruger-Herreros C, Svoboda L, Mogk A, Bukau B. Role of J-domain Proteins in Yeast Physiology and Protein Quality Control. J Mol Biol 2024; 436:168484. [PMID: 38331212 DOI: 10.1016/j.jmb.2024.168484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/02/2024] [Accepted: 02/02/2024] [Indexed: 02/10/2024]
Abstract
The Hsp70 chaperone system is a central component of cellular protein quality control (PQC) by acting in a multitude of protein folding processes ranging from the folding of newly synthesized proteins to the disassembly and refolding of protein aggregates. This multifunctionality of Hsp70 is governed by J-domain proteins (JDPs), which act as indispensable co-chaperones that target specific substrates to Hsp70. The number of distinct JDPs present in a species always outnumbers Hsp70, documenting JDP function in functional diversification of Hsp70. In this review, we describe the physiological roles of JDPs in the Saccharomyces cerevisiae PQC system, with a focus on the abundant JDP generalists, Zuo1, Ydj1 and Sis1, which function in fundamental cellular processes. Ribosome-bound Zuo1 cooperates with the Hsp70 chaperones Ssb1/2 in folding and assembly of nascent polypeptides. Ydj1 and Sis1 cooperate with the Hsp70 members Ssa1 to Ssa4 to exert overlapping functions in protein folding and targeting of newly synthesized proteins to organelles including mitochondria and facilitating the degradation of aberrant proteins by E3 ligases. Furthermore, they act in protein disaggregation reactions, though Ydj1 and Sis1 differ in their modes of Hsp70 cooperation and substrate specificities. This results in functional specialization as seen in prion propagation and the underlying dominant role of Sis1 in targeting Hsp70 for shearing of prion amyloid fibrils.
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Affiliation(s)
- Carmen Ruger-Herreros
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany; Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Avda. Manuel Siurot, s/n, E-41013 Sevilla, Spain
| | - Lucia Svoboda
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Axel Mogk
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
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6
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Creamer DR, Beynon RJ, Hubbard SJ, Ashe MP, Grant CM. Isoform-specific sequestration of protein kinase A fine-tunes intracellular signaling during heat stress. Cell Rep 2024; 43:114360. [PMID: 38865242 DOI: 10.1016/j.celrep.2024.114360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/24/2024] [Accepted: 05/30/2024] [Indexed: 06/14/2024] Open
Abstract
Protein kinase A (PKA) is a conserved kinase crucial for fundamental biological processes linked to growth, development, and metabolism. The PKA catalytic subunit is expressed as multiple isoforms in diverse eukaryotes; however, their contribution to ensuring signaling specificity in response to environmental cues remains poorly defined. Catalytic subunit activity is classically moderated via interaction with an inhibitory regulatory subunit. Here, a quantitative mass spectrometry approach is used to examine heat-stress-induced changes in the binding of yeast Tpk1-3 catalytic subunits to the Bcy1 regulatory subunit. We show that Tpk3 is not regulated by Bcy1 binding but, instead, is deactivated upon heat stress via reversible sequestration into cytoplasmic granules. These "Tpk3 granules" are enriched for multiple PKA substrates involved in various metabolic processes, with the Hsp42 sequestrase required for their formation. Hence, regulated sequestration of Tpk3 provides a mechanism to control isoform-specific kinase signaling activity during stress conditions.
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Affiliation(s)
- Declan R Creamer
- Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Robert J Beynon
- Centre for Proteome Research, Institute of Systems and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK
| | - Simon J Hubbard
- Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Mark P Ashe
- Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Chris M Grant
- Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK.
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7
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Garadi Suresh H, Bonneil E, Albert B, Dominique C, Costanzo M, Pons C, Masinas MPD, Shuteriqi E, Shore D, Henras AK, Thibault P, Boone C, Andrews BJ. K29-linked free polyubiquitin chains affect ribosome biogenesis and direct ribosomal proteins to the intranuclear quality control compartment. Mol Cell 2024; 84:2337-2352.e9. [PMID: 38870935 PMCID: PMC11193623 DOI: 10.1016/j.molcel.2024.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 01/25/2024] [Accepted: 05/17/2024] [Indexed: 06/15/2024]
Abstract
Ribosome assembly requires precise coordination between the production and assembly of ribosomal components. Mutations in ribosomal proteins that inhibit the assembly process or ribosome function are often associated with ribosomopathies, some of which are linked to defects in proteostasis. In this study, we examine the interplay between several yeast proteostasis enzymes, including deubiquitylases (DUBs) Ubp2 and Ubp14, and E3 ligases Ufd4 and Hul5, and we explore their roles in the regulation of the cellular levels of K29-linked unanchored polyubiquitin (polyUb) chains. Accumulating K29-linked unanchored polyUb chains associate with maturing ribosomes to disrupt their assembly, activate the ribosome assembly stress response (RASTR), and lead to the sequestration of ribosomal proteins at the intranuclear quality control compartment (INQ). These findings reveal the physiological relevance of INQ and provide insights into mechanisms of cellular toxicity associated with ribosomopathies.
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Affiliation(s)
- Harsha Garadi Suresh
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada.
| | - Eric Bonneil
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, QC H3C 3J7, Canada
| | - Benjamin Albert
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), Geneva, Switzerland; Molecular, Cellular and Developmental Biology Unit (MCD), Centre for Integrative Biology (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Carine Dominique
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre for Integrative Biology (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Michael Costanzo
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Carles Pons
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute for Science and Technology, Barcelona, Catalonia, Spain
| | - Myra Paz David Masinas
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Ermira Shuteriqi
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - David Shore
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), Geneva, Switzerland
| | - Anthony K Henras
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre for Integrative Biology (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Pierre Thibault
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, QC H3C 3J7, Canada; Department of Chemistry, Université de Montréal, Montréal, QC H3C 3J7, Canada
| | - Charles Boone
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada.
| | - Brenda J Andrews
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada.
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8
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Bertgen L, Bökenkamp JE, Schneckmann T, Koch C, Räschle M, Storchová Z, Herrmann JM. Distinct types of intramitochondrial protein aggregates protect mitochondria against proteotoxic stress. Cell Rep 2024; 43:114018. [PMID: 38551959 DOI: 10.1016/j.celrep.2024.114018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 02/27/2024] [Accepted: 03/14/2024] [Indexed: 04/28/2024] Open
Abstract
Mitochondria consist of hundreds of proteins, most of which are inaccessible to the proteasomal quality control system of the cytosol. How cells stabilize the mitochondrial proteome during challenging conditions remains poorly understood. Here, we show that mitochondria form spatially defined protein aggregates as a stress-protecting mechanism. Two different types of intramitochondrial protein aggregates can be distinguished. The mitoribosomal protein Var1 (uS3m) undergoes a stress-induced transition from a soluble, chaperone-stabilized protein that is prevalent under benign conditions to an insoluble, aggregated form upon acute stress. The formation of Var1 bodies stabilizes mitochondrial proteostasis, presumably by sequestration of aggregation-prone proteins. The AAA chaperone Hsp78 is part of a second type of intramitochondrial aggregate that transiently sequesters proteins and promotes their folding or Pim1-mediated degradation. Thus, mitochondrial proteins actively control the formation of distinct types of intramitochondrial protein aggregates, which cooperate to stabilize the mitochondrial proteome during proteotoxic stress conditions.
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Affiliation(s)
- Lea Bertgen
- Cell Biology, University of Kaiserslautern, RPTU, Erwin-Schrödinger-Strasse 13, 67663 Kaiserslautern, Germany
| | - Jan-Eric Bökenkamp
- Molecular Genetics, University of Kaiserslautern, RPTU, Paul-Ehrlich-Strasse 24, 67663 Kaiserslautern, Germany
| | - Tim Schneckmann
- Cell Biology, University of Kaiserslautern, RPTU, Erwin-Schrödinger-Strasse 13, 67663 Kaiserslautern, Germany
| | - Christian Koch
- Cell Biology, University of Kaiserslautern, RPTU, Erwin-Schrödinger-Strasse 13, 67663 Kaiserslautern, Germany
| | - Markus Räschle
- Molecular Genetics, University of Kaiserslautern, RPTU, Paul-Ehrlich-Strasse 24, 67663 Kaiserslautern, Germany
| | - Zuzana Storchová
- Molecular Genetics, University of Kaiserslautern, RPTU, Paul-Ehrlich-Strasse 24, 67663 Kaiserslautern, Germany
| | - Johannes M Herrmann
- Cell Biology, University of Kaiserslautern, RPTU, Erwin-Schrödinger-Strasse 13, 67663 Kaiserslautern, Germany.
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9
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Kumar A, Mathew V, Stirling PC. Dynamics of DNA damage-induced nuclear inclusions are regulated by SUMOylation of Btn2. Nat Commun 2024; 15:3215. [PMID: 38615096 PMCID: PMC11016081 DOI: 10.1038/s41467-024-47615-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 04/05/2024] [Indexed: 04/15/2024] Open
Abstract
Spatial compartmentalization is a key facet of protein quality control that serves to store disassembled or non-native proteins until triage to the refolding or degradation machinery can occur in a regulated manner. Yeast cells sequester nuclear proteins at intranuclear quality control bodies (INQ) in response to various stresses, although the regulation of this process remains poorly understood. Here we reveal the SUMO modification of the small heat shock protein Btn2 under DNA damage and place Btn2 SUMOylation in a pathway promoting protein clearance from INQ structures. Along with other chaperones, and degradation machinery, Btn2-SUMO promotes INQ clearance from cells recovering from genotoxic stress. These data link small heat shock protein post-translational modification to the regulation of protein sequestration in the yeast nucleus.
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Affiliation(s)
- Arun Kumar
- Terry Fox Laboratory, BC Cancer, 675 West 10th Avenue, Vancouver, BC, V5Z1L3, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T1Z4, Canada
| | - Veena Mathew
- Terry Fox Laboratory, BC Cancer, 675 West 10th Avenue, Vancouver, BC, V5Z1L3, Canada
| | - Peter C Stirling
- Terry Fox Laboratory, BC Cancer, 675 West 10th Avenue, Vancouver, BC, V5Z1L3, Canada.
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T1Z4, Canada.
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10
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Goncalves D, Duy DL, Peffer S, Morano KA. Cytoplasmic redox imbalance in the thioredoxin system activates Hsf1 and results in hyperaccumulation of the sequestrase Hsp42 with misfolded proteins. Mol Biol Cell 2024; 35:ar53. [PMID: 38381577 PMCID: PMC11064659 DOI: 10.1091/mbc.e23-07-0296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 02/09/2024] [Accepted: 02/16/2024] [Indexed: 02/23/2024] Open
Abstract
Cells employ multiple systems to maintain homeostasis when experiencing environmental stress. For example, the folding of nascent polypeptides is exquisitely sensitive to proteotoxic stressors including heat, pH, and oxidative stress, and is safeguarded by a network of protein chaperones that concentrate potentially toxic misfolded proteins into transient assemblies to promote folding or degradation. The redox environment itself is buffered by both cytosolic and organellar thioredoxin and glutathione pathways. How these systems are linked is poorly understood. Here, we determine that specific disruption of the cytosolic thioredoxin system resulted in constitutive activation of the heat shock response in Saccharomyces cerevisiae and accumulation of the sequestrase Hsp42 into an exaggerated and persistent juxtanuclear quality control (JUNQ) compartment. Terminally misfolded proteins also accumulated in this compartment in thioredoxin reductase (TRR1)-deficient cells, despite apparently normal formation and dissolution of transient cytoplasmic quality control (CytoQ) bodies during heat shock. Notably, cells lacking TRR1 and HSP42 exhibited severe synthetic slow growth exacerbated by oxidative stress, signifying a critical role for Hsp42 under redox-challenged conditions. Finally, we demonstrated that Hsp42 localization patterns in trr1∆ cells mimic those observed in chronically aging and glucose-starved cells, linking nutrient depletion and redox imbalance with management of misfolded proteins via a process of long-term sequestration.
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Affiliation(s)
- Davi Goncalves
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth Houston, Houston, TX 77030
| | - Duong Long Duy
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth Houston, Houston, TX 77030
| | - Sara Peffer
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth Houston, Houston, TX 77030
- Microbiology and Infectious Disease Program, MD Anderson UTHealth Graduate School at UTHealth Houston, Houston, TX 77030
| | - Kevin A. Morano
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth Houston, Houston, TX 77030
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11
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Minoia M, Quintana-Cordero J, Jetzinger K, Kotan IE, Turnbull KJ, Ciccarelli M, Masser AE, Liebers D, Gouarin E, Czech M, Hauryliuk V, Bukau B, Kramer G, Andréasson C. Chp1 is a dedicated chaperone at the ribosome that safeguards eEF1A biogenesis. Nat Commun 2024; 15:1382. [PMID: 38360885 PMCID: PMC10869706 DOI: 10.1038/s41467-024-45645-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 01/29/2024] [Indexed: 02/17/2024] Open
Abstract
Cotranslational protein folding depends on general chaperones that engage highly diverse nascent chains at the ribosomes. Here we discover a dedicated ribosome-associated chaperone, Chp1, that rewires the cotranslational folding machinery to assist in the challenging biogenesis of abundantly expressed eukaryotic translation elongation factor 1A (eEF1A). Our results indicate that during eEF1A synthesis, Chp1 is recruited to the ribosome with the help of the nascent polypeptide-associated complex (NAC), where it safeguards eEF1A biogenesis. Aberrant eEF1A production in the absence of Chp1 triggers instant proteolysis, widespread protein aggregation, activation of Hsf1 stress transcription and compromises cellular fitness. The expression of pathogenic eEF1A2 variants linked to epileptic-dyskinetic encephalopathy is protected by Chp1. Thus, eEF1A is a difficult-to-fold protein that necessitates a biogenesis pathway starting with dedicated folding factor Chp1 at the ribosome to protect the eukaryotic cell from proteostasis collapse.
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Affiliation(s)
- Melania Minoia
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Jany Quintana-Cordero
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Katharina Jetzinger
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Ilgin Eser Kotan
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Kathryn Jane Turnbull
- Department of Clinical Microbiology, Rigshospitalet, 2200, Copenhagen, Denmark
- Department of Molecular Biology, Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Science for Life Laboratory, Umeå University, Umeå, Sweden
| | - Michela Ciccarelli
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Anna E Masser
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Dorina Liebers
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Eloïse Gouarin
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Marius Czech
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Vasili Hauryliuk
- Science for Life Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
- University of Tartu, Institute of Technology, 50411, Tartu, Estonia
| | - Bernd Bukau
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Günter Kramer
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
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12
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Lehmann CP, González-Fernández P, Tercero J. Spatial regulation of DNA damage tolerance protein Rad5 interconnects genome stability maintenance and proteostasis networks. Nucleic Acids Res 2024; 52:1156-1172. [PMID: 38055836 PMCID: PMC10853803 DOI: 10.1093/nar/gkad1176] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/21/2023] [Accepted: 11/23/2023] [Indexed: 12/08/2023] Open
Abstract
The Rad5/HLTF protein has a central role in the tolerance to DNA damage by mediating an error-free mode of bypassing unrepaired DNA lesions, and is therefore critical for the maintenance of genome stability. We show in this work that, following cellular stress, Rad5 is regulated by relocalization into two types of nuclear foci that coexist within the same cell, which we termed 'S' and 'I'. Rad5 S-foci form in response to genotoxic stress and are associated with Rad5's function in maintaining genome stability, whereas I-foci form in the presence of proteotoxic stress and are related to Rad5's own proteostasis. Rad5 accumulates into S-foci at DNA damage tolerance sites by liquid-liquid phase separation, while I-foci constitute sites of chaperone-mediated sequestration of Rad5 at the intranuclear quality control compartment (INQ). Relocalization of Rad5 into each type of foci involves different pathways and recruitment mechanisms, but in both cases is driven by the evolutionarily conserved E2 ubiquitin-conjugating enzyme Rad6. This coordinated differential relocalization of Rad5 interconnects DNA damage response and proteostasis networks, highlighting the importance of studying these homeostasis mechanisms in tandem. Spatial regulation of Rad5 under cellular stress conditions thus provides a useful biological model to study cellular homeostasis as a whole.
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Affiliation(s)
- Carl P Lehmann
- Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Cantoblanco. 28049-Madrid, Spain
| | | | - José Antonio Tercero
- Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Cantoblanco. 28049-Madrid, Spain
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13
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Carter Z, Creamer D, Kouvidi A, Grant CM. Sequestrase chaperones protect against oxidative stress-induced protein aggregation and [PSI+] prion formation. PLoS Genet 2024; 20:e1011194. [PMID: 38422160 DOI: 10.1371/journal.pgen.1011194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 03/12/2024] [Accepted: 02/20/2024] [Indexed: 03/02/2024] Open
Abstract
Misfolded proteins are usually refolded to their functional conformations or degraded by quality control mechanisms. When misfolded proteins evade quality control, they can be sequestered to specific sites within cells to prevent the potential dysfunction and toxicity that arises from protein aggregation. Btn2 and Hsp42 are compartment-specific sequestrases that play key roles in the assembly of these deposition sites. Their exact intracellular functions and substrates are not well defined, particularly since heat stress sensitivity is not observed in deletion mutants. We show here that Btn2 and Hsp42 are required for tolerance to oxidative stress conditions induced by exposure to hydrogen peroxide. Btn2 and Hsp42 act to sequester oxidized proteins into defined PQC sites following ROS exposure and their absence leads to an accumulation of protein aggregates. The toxicity of protein aggregate accumulation causes oxidant sensitivity in btn2 hsp42 sequestrase mutants since overexpression of the Hsp104 disaggregase rescues oxidant tolerance. We have identified the Sup35 translation termination factor as an in vivo sequestrase substrate and show that Btn2 and Hsp42 act to suppress oxidant-induced formation of the yeast [PSI+] prion, which is the amyloid form of Sup35. [PSI+] prion formation in sequestrase mutants does not require IPOD (insoluble protein deposit) localization which is the site where amyloids are thought to undergo fragmentation and seeding to propagate their heritable prion form. Instead, both amorphous and amyloid Sup35 aggregates are increased in btn2 hsp42 mutants consistent with the idea that prion formation occurs at multiple intracellular sites during oxidative stress conditions in the absence of sequestrase activity. Taken together, our data identify protein sequestration as a key antioxidant defence mechanism that functions to mitigate the damaging consequences of protein oxidation-induced aggregation.
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Affiliation(s)
- Zorana Carter
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, United Kingdom
| | - Declan Creamer
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, United Kingdom
| | - Aikaterini Kouvidi
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, United Kingdom
| | - Chris M Grant
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, United Kingdom
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14
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Ando R, Ishikawa Y, Kamada Y, Izawa S. Contribution of the yeast bi-chaperone system in the restoration of the RNA helicase Ded1 and translational activity under severe ethanol stress. J Biol Chem 2023; 299:105472. [PMID: 37979914 PMCID: PMC10746526 DOI: 10.1016/j.jbc.2023.105472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 10/30/2023] [Accepted: 11/03/2023] [Indexed: 11/20/2023] Open
Abstract
Preexposure to mild stress often improves cellular tolerance to subsequent severe stress. Severe ethanol stress (10% v/v) causes persistent and pronounced translation repression in Saccharomyces cerevisiae. However, it remains unclear whether preexposure to mild stress can mitigate translation repression in yeast cells under severe ethanol stress. We found that the translational activity of yeast cells pretreated with 6% (v/v) ethanol was initially significantly repressed under subsequent 10% ethanol but was then gradually restored even under severe ethanol stress. We also found that 10% ethanol caused the aggregation of Ded1, which plays a key role in translation initiation as a DEAD-box RNA helicase. Pretreatment with 6% ethanol led to the gradual disaggregation of Ded1 under subsequent 10% ethanol treatment in wild-type cells but not in fes1Δhsp104Δ cells, which are deficient in Hsp104 with significantly reduced capacity for Hsp70. Hsp104 and Hsp70 are key components of the bi-chaperone system that play a role in yeast protein quality control. fes1Δhsp104Δ cells did not restore translational activity under 10% ethanol, even after pretreatment with 6% ethanol. These results indicate that the regeneration of Ded1 through the bi-chaperone system leads to the gradual restoration of translational activity under continuous severe stress. This study provides new insights into the acquired tolerance of yeast cells to severe ethanol stress and the resilience of their translational activity.
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Affiliation(s)
- Ryoko Ando
- Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Kyoto, Japan
| | - Yu Ishikawa
- Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Kyoto, Japan
| | | | - Shingo Izawa
- Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Kyoto, Japan.
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15
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Wu Y, Zhao J, Tian Y, Jin H. Cellular functions of heat shock protein 20 (HSPB6) in cancer: A review. Cell Signal 2023; 112:110928. [PMID: 37844714 DOI: 10.1016/j.cellsig.2023.110928] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/07/2023] [Accepted: 10/13/2023] [Indexed: 10/18/2023]
Abstract
Heat shock proteins (HSP) are a large family of peptide proteins that are widely found in cells. Studies have shown that the expression and function of HSPs in cells are very complex, and they can participate in cellular physiological and pathological processes through multiple pathways. Multiple heat shock proteins are associated with cancer cell growth, proliferation, metastasis, and resistance to anticancer drugs, and they play a key role in cancer development by ensuring the correct folding or degradation of proteins in cancer cells. As research hotspots, HSP90, HSP70 and HSP27 have been extensively studied in cancer so far. However, HSP20, also referred to as HSPB6, as a member of the small heat shock protein family, has been shown to play an important role in the cardiovascular system, but little research has been conducted on HSP20 in cancer. This review summarizes the current cellular functions of HSP20 in different cancer types, as well as its effects on cancer proliferation, progression, prognosis, and its other functions in cancer, to illustrate the close association between HSP20 and cancer. We show that, unlike most HSPs, HSP20 mainly plays an active anticancer role in cancer development, which is expected to provide new ideas and help for cancer diagnosis and treatment and research.
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Affiliation(s)
- Yifeng Wu
- Department of General Surgery, Wuxi 9th People's Hospital Affiliated to Soochow University, Wuxi, Jiangsu 214000, People's Republic of China
| | - Jinjin Zhao
- Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210029, People's Republic of China
| | - Yun Tian
- Department of Oncology, Jiangsu Province Hospital of Chinese Medicine Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210029, People's Republic of China.
| | - Hongdou Jin
- Department of General Surgery, Wuxi 9th People's Hospital Affiliated to Soochow University, Wuxi, Jiangsu 214000, People's Republic of China.
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16
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Boronat S, Cabrera M, Vega M, Alcalá J, Salas-Pino S, Daga RR, Ayté J, Hidalgo E. Formation of Transient Protein Aggregate-like Centers Is a General Strategy Postponing Degradation of Misfolded Intermediates. Int J Mol Sci 2023; 24:11202. [PMID: 37446379 DOI: 10.3390/ijms241311202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 07/15/2023] Open
Abstract
When misfolded intermediates accumulate during heat shock, the protein quality control system promotes cellular adaptation strategies. In Schizosaccharomyces pombe, thermo-sensitive proteins assemble upon stress into protein aggregate-like centers, PACs, to escape from degradation. The role of this protein deposition strategy has been elusive due to the use of different model systems and reporters, and to the addition of artificial inhibitors, which made interpretation of the results difficult. Here, we compare fission and budding yeast model systems, expressing the same misfolding reporters in experiments lacking proteasome or translation inhibitors. We demonstrate that mild heat shock triggers reversible PAC formation, with the collapse of both reporters and chaperones in a process largely mediated by chaperones. This assembly postpones proteasomal degradation of the misfolding reporters, and their Hsp104-dependent disassembly occurs during stress recovery. Severe heat shock induces formation of cytosolic PACs, but also of nuclear structures resembling nucleolar rings, NuRs, presumably to halt nuclear functions. Our study demonstrates that these distantly related yeasts use very similar strategies to adapt and survive to mild and severe heat shock and that aggregate-like formation is a general cellular scheme to postpone protein degradation and facilitate exit from stress.
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Affiliation(s)
- Susanna Boronat
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Doctor Aiguader 88, 08003 Barcelona, Spain
| | - Margarita Cabrera
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Doctor Aiguader 88, 08003 Barcelona, Spain
- Centro de Biología Molecular Severo Ochoa and Departamento de Biología Molecular, Universidad Autónoma de Madrid (UAM), 28049 Madrid, Spain
| | - Montserrat Vega
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Doctor Aiguader 88, 08003 Barcelona, Spain
| | - Jorge Alcalá
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Doctor Aiguader 88, 08003 Barcelona, Spain
| | - Silvia Salas-Pino
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Carretera de Utrera, km1, 41013 Seville, Spain
| | - Rafael R Daga
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Carretera de Utrera, km1, 41013 Seville, Spain
| | - José Ayté
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Doctor Aiguader 88, 08003 Barcelona, Spain
| | - Elena Hidalgo
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Doctor Aiguader 88, 08003 Barcelona, Spain
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17
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Fischbach A, Johns A, Schneider KL, Hao X, Tessarz P, Nyström T. Artificial Hsp104-mediated systems for re-localizing protein aggregates. Nat Commun 2023; 14:2663. [PMID: 37160881 PMCID: PMC10169802 DOI: 10.1038/s41467-023-37706-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 03/28/2023] [Indexed: 05/11/2023] Open
Abstract
Spatial Protein Quality Control (sPQC) sequesters misfolded proteins into specific, organelle-associated inclusions within the cell to control their toxicity. To approach the role of sPQC in cellular fitness, neurodegenerative diseases and aging, we report on the construction of Hsp100-based systems in budding yeast cells, which can artificially target protein aggregates to non-canonical locations. We demonstrate that aggregates of mutant huntingtin (mHtt), the disease-causing agent of Huntington's disease can be artificially targeted to daughter cells as well as to eisosomes and endosomes with this approach. We find that the artificial removal of mHtt inclusions from mother cells protects them from cell death suggesting that even large mHtt inclusions may be cytotoxic, a trait that has been widely debated. In contrast, removing inclusions of endogenous age-associated misfolded proteins does not significantly affect the lifespan of mother cells. We demonstrate also that this approach is able to manipulate mHtt inclusion formation in human cells and has the potential to be useful as an alternative, complementary approach to study the role of sPQC, for example in aging and neurodegenerative disease.
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Affiliation(s)
- Arthur Fischbach
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health-AgeCap, University of Gothenburg, Gothenburg, Sweden.
- Max-Planck Research Group Chromatin and Ageing, Max Planck Institute for Biology of Ageing, Cologne, Germany.
| | - Angela Johns
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health-AgeCap, University of Gothenburg, Gothenburg, Sweden
| | - Kara L Schneider
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health-AgeCap, University of Gothenburg, Gothenburg, Sweden
| | - Xinxin Hao
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health-AgeCap, University of Gothenburg, Gothenburg, Sweden
| | - Peter Tessarz
- Max-Planck Research Group Chromatin and Ageing, Max Planck Institute for Biology of Ageing, Cologne, Germany
- Cologne Excellence Cluster on Stress Responses in Ageing-Associated Diseases (CECAD), Cologne, Germany
| | - Thomas Nyström
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health-AgeCap, University of Gothenburg, Gothenburg, Sweden.
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18
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Suresh HG, Bonneil E, Albert B, Dominique C, Costanzo M, Pons C, David Masinas MP, Shuteriqi E, Shore D, Henras AK, Thibault P, Boone C, Andrews BJ. K29-linked unanchored polyubiquitin chains disrupt ribosome biogenesis and direct ribosomal proteins to the Intranuclear Quality control compartment (INQ). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.03.539259. [PMID: 37205480 PMCID: PMC10187189 DOI: 10.1101/2023.05.03.539259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Ribosome assembly requires precise coordination between the production and assembly of ribosomal components. Mutations in ribosomal proteins that inhibit the assembly process or ribosome function are often associated with Ribosomopathies, some of which are linked to defects in proteostasis. In this study, we examine the interplay between several yeast proteostasis enzymes, including deubiquitylases (DUBs), Ubp2 and Ubp14, and E3 ligases, Ufd4 and Hul5, and we explore their roles in the regulation of the cellular levels of K29-linked unanchored polyubiquitin (polyUb) chains. Accumulating K29-linked unanchored polyUb chains associate with maturing ribosomes to disrupt their assembly, activate the Ribosome assembly stress response (RASTR), and lead to the sequestration of ribosomal proteins at the Intranuclear Quality control compartment (INQ). These findings reveal the physiological relevance of INQ and provide insights into mechanisms of cellular toxicity associated with Ribosomopathies.
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19
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Krämer L, Dalheimer N, Räschle M, Storchová Z, Pielage J, Boos F, Herrmann JM. MitoStores: chaperone-controlled protein granules store mitochondrial precursors in the cytosol. EMBO J 2023; 42:e112309. [PMID: 36704946 PMCID: PMC10068336 DOI: 10.15252/embj.2022112309] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 01/05/2023] [Accepted: 01/12/2023] [Indexed: 01/28/2023] Open
Abstract
Hundreds of nucleus-encoded mitochondrial precursor proteins are synthesized in the cytosol and imported into mitochondria in a post-translational manner. However, the early processes associated with mitochondrial protein targeting remain poorly understood. Here, we show that in Saccharomyces cerevisiae, the cytosol has the capacity to transiently store mitochondrial matrix-destined precursors in dedicated deposits that we termed MitoStores. Competitive inhibition of mitochondrial protein import via clogging of import sites greatly enhances the formation of MitoStores, but they also form during physiological cell growth on nonfermentable carbon sources. MitoStores are enriched for a specific subset of nucleus-encoded mitochondrial proteins, in particular those containing N-terminal mitochondrial targeting sequences. Our results suggest that MitoStore formation suppresses the toxic potential of aberrantly accumulating mitochondrial precursor proteins and is controlled by the heat shock proteins Hsp42 and Hsp104. Thus, the cytosolic protein quality control system plays an active role during the early stages of mitochondrial protein targeting through the coordinated and localized sequestration of mitochondrial precursor proteins.
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Affiliation(s)
- Lena Krämer
- Cell BiologyUniversity of KaiserslauternKaiserslauternGermany
| | - Niko Dalheimer
- Cell BiologyUniversity of KaiserslauternKaiserslauternGermany
- Present address:
Cellular BiochemistryMax Planck Institute of BiochemistryMartinsriedGermany
| | - Markus Räschle
- Molecular GeneticsUniversity of KaiserslauternKaiserslauternGermany
| | - Zuzana Storchová
- Molecular GeneticsUniversity of KaiserslauternKaiserslauternGermany
| | - Jan Pielage
- Zoology and NeurobiologyUniversity of KaiserslauternKaiserslauternGermany
| | - Felix Boos
- Cell BiologyUniversity of KaiserslauternKaiserslauternGermany
- Present address:
Department of GeneticsStanford UniversityStanfordCAUSA
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20
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Jawed A, Ho CT, Grousl T, Shrivastava A, Ruppert T, Bukau B, Mogk A. Balanced activities of Hsp70 and the ubiquitin proteasome system underlie cellular protein homeostasis. Front Mol Biosci 2023; 9:1106477. [PMID: 36660429 PMCID: PMC9845930 DOI: 10.3389/fmolb.2022.1106477] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 12/15/2022] [Indexed: 01/05/2023] Open
Abstract
To counteract proteotoxic stress and cellular aging, protein quality control (PQC) systems rely on the refolding, degradation and sequestration of misfolded proteins. In Saccharomyces cerevisiae the Hsp70 chaperone system plays a central role in protein refolding, while degradation is predominantly executed by the ubiquitin proteasome system (UPS). The sequestrases Hsp42 and Btn2 deposit misfolded proteins in cytosolic and nuclear inclusions, thereby restricting the accessibility of misfolded proteins to Hsp70 and preventing the exhaustion of limited Hsp70 resources. Therefore, in yeast, sequestrase mutants show negative genetic interactions with double mutants lacking the Hsp70 co-chaperone Fes1 and the Hsp104 disaggregase (fes1Δ hsp104Δ, ΔΔ) and suffering from low Hsp70 capacity. Growth of ΔΔbtn2Δ mutants is highly temperature-sensitive and results in proteostasis breakdown at non-permissive temperatures. Here, we probed for the role of the ubiquitin proteasome system in maintaining protein homeostasis in ΔΔbtn2Δ cells, which are affected in two major protein quality control branches. We show that ΔΔbtn2Δ cells induce expression of diverse stress-related pathways including the ubiquitin proteasome system to counteract the proteostasis defects. Ubiquitin proteasome system dependent degradation of the stringent Hsp70 substrate firefly Luciferase in the mutant cells mirrors such compensatory activities of the protein quality control system. Surprisingly however, the enhanced ubiquitin proteasome system activity does not improve but aggravates the growth defects of ΔΔbtn2Δ cells. Reducing ubiquitin proteasome system activity in the mutant by lowering the levels of functional 26S proteasomes improved growth, increased refolding yield of the Luciferase reporter and attenuated global stress responses. Our findings indicate that an imbalance between Hsp70-dependent refolding, sequestration and ubiquitin proteasome system-mediated degradation activities strongly affects protein homeostasis of Hsp70 capacity mutants and contributes to their severe growth phenotypes.
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Affiliation(s)
- Areeb Jawed
- Center for Molecular Biology of Heidelberg University (ZMBH), University of Heidelberg, Heidelberg, Germany,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Chi-Ting Ho
- Center for Molecular Biology of Heidelberg University (ZMBH), University of Heidelberg, Heidelberg, Germany,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Tomas Grousl
- Center for Molecular Biology of Heidelberg University (ZMBH), University of Heidelberg, Heidelberg, Germany,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Aseem Shrivastava
- Center for Molecular Biology of Heidelberg University (ZMBH), University of Heidelberg, Heidelberg, Germany,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Thomas Ruppert
- Center for Molecular Biology of Heidelberg University (ZMBH), University of Heidelberg, Heidelberg, Germany
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH), University of Heidelberg, Heidelberg, Germany,German Cancer Research Center (DKFZ), Heidelberg, Germany,*Correspondence: Axel Mogk, ; Bernd Bukau,
| | - Axel Mogk
- Center for Molecular Biology of Heidelberg University (ZMBH), University of Heidelberg, Heidelberg, Germany,German Cancer Research Center (DKFZ), Heidelberg, Germany,*Correspondence: Axel Mogk, ; Bernd Bukau,
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21
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Furutani N, Izawa S. Adaptability of wine yeast to ethanol-induced protein denaturation. FEMS Yeast Res 2022; 22:6831633. [PMID: 36385376 DOI: 10.1093/femsyr/foac059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/28/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022] Open
Abstract
This year marks the 200th anniversary of the birth of Dr Louis Pasteur (1822-1895), who revealed that alcoholic fermentation is performed by yeast cells. Subsequently, details of the mechanisms of alcoholic fermentation and glycolysis in yeast cells have been elucidated. However, the mechanisms underlying the high tolerance and adaptability of yeast cells to ethanol are not yet fully understood. This review presents the response and adaptability of yeast cells to ethanol-induced protein denaturation. Herein, we describe the adverse effects of severe ethanol stress on intracellular proteins and the responses of yeast cells. Furthermore, recent findings on the acquired resistance of wine yeast cells to severe ethanol stress that causes protein denaturation are discussed, not only under laboratory conditions, but also during the fermentation process at 15°C to mimic the vinification process of white wine.
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Affiliation(s)
- Noboru Furutani
- Laboratory of Microbial Technology, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Kyoto 606-8585, Japan
| | - Shingo Izawa
- Laboratory of Microbial Technology, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Kyoto 606-8585, Japan
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22
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Wine Yeast Cells Acquire Resistance to Severe Ethanol Stress and Suppress Insoluble Protein Accumulation during Alcoholic Fermentation. Microbiol Spectr 2022; 10:e0090122. [PMID: 36040149 PMCID: PMC9603993 DOI: 10.1128/spectrum.00901-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Under laboratory conditions, acute 10% (vol/vol) ethanol stress causes protein denaturation and accumulation of insoluble proteins in yeast cells. However, yeast cells can acquire resistance to severe ethanol stress by pretreatment with mild ethanol stress (6% vol/vol) and mitigate insoluble protein accumulation under subsequent exposure to 10% (vol/vol) ethanol. On the other hand, protein quality control (PQC) of yeast cells during winemaking remains poorly understood. Ethanol concentrations in the grape must increase gradually, rather than acutely, to more than 10% (vol/vol) during the winemaking process. Gradual increases in ethanol evoke two possibilities for yeast PQC under high ethanol concentrations in the must: suppression of insoluble protein accumulation through the acquisition of resistance or the accumulation of denatured insoluble proteins. We examined these two possibilities by conducting alcoholic fermentation tests at 15°C that mimic white winemaking using synthetic grape must (SGM). The results obtained revealed the negligible accumulation of insoluble proteins in wine yeast cells throughout the fermentation process. Furthermore, wine yeast cells in fermenting SGM did not accumulate insoluble proteins when transferred to synthetic defined (SD) medium containing 10% (vol/vol) ethanol. Conversely, yeast cells cultured in SD medium accumulated insoluble proteins when transferred to fermented SGM containing 9.8% (vol/vol) ethanol. Thus, wine yeast cells acquire resistance to the cellular impact of severe ethanol stress during fermentation and mitigate the accumulation of insoluble proteins. This study provides novel insights into the PQC and robustness of wine yeast during winemaking. IMPORTANCE Winemaking is a dynamic and complex process in which ethanol concentrations gradually increase to reach >10% (vol/vol) through alcoholic fermentation. However, there is little information on protein damage in wine yeast during winemaking. We investigated the insoluble protein levels of wine yeast under laboratory conditions in SD medium and during fermentation in SGM. Under laboratory conditions, wine yeast cells, as well as laboratory strain cells, accumulated insoluble proteins under acute 10% (vol/vol) ethanol stress, and this accumulation was suppressed by pretreatment with 6% (vol/vol) ethanol. During the fermentation process, insoluble protein levels were maintained at low levels in wine yeast even when the SGM ethanol concentration exceeded 10% (vol/vol). These results indicate that the progression of wine yeast through fermentation in SGM results in stress tolerance, similar to the pretreatment of cells with mild ethanol stress. These findings further the understanding of yeast cell physiology during winemaking.
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Shrivastava A, Sandhof CA, Reinle K, Jawed A, Ruger-Herreros C, Schwarz D, Creamer D, Nussbaum-Krammer C, Mogk A, Bukau B. The cytoprotective sequestration activity of small heat shock proteins is evolutionarily conserved. J Cell Biol 2022; 221:213447. [PMID: 36069810 PMCID: PMC9458469 DOI: 10.1083/jcb.202202149] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 07/21/2022] [Accepted: 08/16/2022] [Indexed: 11/22/2022] Open
Abstract
The chaperone-mediated sequestration of misfolded proteins into inclusions is a pivotal cellular strategy to maintain proteostasis in Saccharomyces cerevisiae, executed by small heat shock proteins (sHsps) Hsp42 and Btn2. Direct homologs of Hsp42 and Btn2 are absent in other organisms, questioning whether sequestration represents a conserved proteostasis strategy and, if so, which factors are involved. We examined sHsps from Escherchia coli, Caenorhabditis elegans, and humans for their ability to complement the defects of yeast sequestrase mutants. We show that sequestration of misfolded proteins is an original and widespread activity among sHsps executed by specific family members. Sequestrase positive C. elegans' sHsps harbor specific sequence features, including a high content of aromatic and methionine residues in disordered N-terminal extensions. Those sHsps buffer limitations in Hsp70 capacity in C. elegans WT animals and are upregulated in long-lived daf-2 mutants, contributing to lifespan extension. Cellular protection by sequestration of misfolded proteins is, therefore, an evolutionarily conserved activity of the sHsp family.
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Affiliation(s)
- Aseem Shrivastava
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Carl Alexander Sandhof
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kevin Reinle
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Areeb Jawed
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Carmen Ruger-Herreros
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Dominic Schwarz
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Declan Creamer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Carmen Nussbaum-Krammer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Axel Mogk
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
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Wickner RB, Edskes HK, Son M, Wu S. Anti-Prion Systems Block Prion Transmission, Attenuate Prion Generation, Cure Most Prions as They Arise and Limit Prion-Induced Pathology in Saccharomyces cerevisiae. BIOLOGY 2022; 11:biology11091266. [PMID: 36138748 PMCID: PMC9495834 DOI: 10.3390/biology11091266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/08/2022] [Accepted: 08/16/2022] [Indexed: 11/16/2022]
Abstract
Simple Summary Virus and bacterial infections are opposed by their hosts at many levels. Similarly, we find that infectious proteins (prions) are severely restricted by an array of host systems, acting independently to prevent infection, generation, propagation and the ill effects of yeast prions. These ‘anti-prion systems’ work in normal cells without the overproduction or deficiency of any components. DNA repair systems reverse the effects of DNA damage, with only a rare lesion propagated as a mutation. Similarly, the combined effects of several anti-prion systems cure and block the generation of all but 1 in about 5000 prions arising. We expect that application of our approach to mammalian cells will detect analogous or even homologous systems that will be useful in devising therapy for human amyloidoses, most of which are prions. Abstract All variants of the yeast prions [PSI+] and [URE3] are detrimental to their hosts, as shown by the dramatic slowing of growth (or even lethality) of a majority, by the rare occurrence in wild isolates of even the mildest variants and by the absence of reproducible benefits of these prions. To deal with the prion problem, the host has evolved an array of anti-prion systems, acting in normal cells (without overproduction or deficiency of any component) to block prion transmission from other cells, to lower the rates of spontaneous prion generation, to cure most prions as they arise and to limit the damage caused by those variants that manage to elude these (necessarily) imperfect defenses. Here we review the properties of prion protein sequence polymorphisms Btn2, Cur1, Hsp104, Upf1,2,3, ribosome-associated chaperones, inositol polyphosphates, Sis1 and Lug1, which are responsible for these anti-prion effects. We recently showed that the combined action of ribosome-associated chaperones, nonsense-mediated decay factors and the Hsp104 disaggregase lower the frequency of [PSI+] appearance as much as 5000-fold. Moreover, while Btn2 and Cur1 are anti-prion factors against [URE3] and an unrelated artificial prion, they promote [PSI+] prion generation and propagation.
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Antiprion systems in yeast cooperate to cure or prevent the generation of nearly all [ PSI+] and [URE3] prions. Proc Natl Acad Sci U S A 2022; 119:e2205500119. [PMID: 35787049 PMCID: PMC9282430 DOI: 10.1073/pnas.2205500119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
[PSI+] and [URE3] are prions of Saccharomyces cerevisiae based on amyloids of Sup35p and Ure2p, respectively. In normal cells, antiprion systems block prion formation, cure many prions that arise, prevent infection by prions, and prevent toxicity of those prions that escape the other systems. The upf1Δ, ssz1Δ, and hsp104T160M single mutants each develop [PSI+] at 10- to 15-fold, but the triple mutant spontaneously generates [PSI+] at up to ∼5,000-fold the wild-type rate. Most such [PSI+] variants are cured by restoration of any one of the three defective antiprion systems, defining a previously unknown type of [PSI+] variant and proving that these three antiprion systems act independently. Generation of [PSI+] variants stable in wild-type cells is also increased in upf1Δ ssz1Δ hsp104T160M strains 25- to 500-fold. Btn2 and Cur1 each cure 90% of [URE3] prions generated in their absence, but we find that btn2Δ or cur1Δ diminishes the frequency of [PSI+] generation in an otherwise wild-type strain. Most [PSI+] isolates in a wild-type strain are destabilized on transfer to a btn2Δ or cur1Δ host. Single upf1Δ or hsp104T160M mutants show the effects of btn2Δ or cur1Δ but not upf1Δ ssz1Δ hsp104T160M or ssz1Δ hsp104T160M strains. The disparate action of Btn2 on [URE3] and [PSI+] may be a result of [PSI+]'s generally higher seed number and lower amyloid structural stability compared with [URE3]. Thus, prion generation is not a rare event, but the escape of a nascent prion from the surveillance by the antiprion systems is indeed rare.
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26
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Kumar A, Mathew V, Stirling PC. Nuclear protein quality control in yeast: the latest INQuiries. J Biol Chem 2022; 298:102199. [PMID: 35760103 PMCID: PMC9305344 DOI: 10.1016/j.jbc.2022.102199] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 06/07/2022] [Accepted: 06/19/2022] [Indexed: 11/29/2022] Open
Abstract
The nucleus is a highly organized organelle with an intricate substructure of chromatin, RNAs, and proteins. This environment represents a challenge for maintaining protein quality control, since non-native proteins may interact inappropriately with other macromolecules and thus interfere with their function. Maintaining a healthy nuclear proteome becomes imperative during times of stress, such as upon DNA damage, heat shock, or starvation, when the proteome must be remodeled to effect cell survival. This is accomplished with the help of nuclear-specific chaperones, degradation pathways, and specialized structures known as protein quality control (PQC) sites that sequester proteins to help rapidly remodel the nuclear proteome. In this review, we focus on the current knowledge of PQC sites in Saccharomyces cerevisiae, particularly on a specialized nuclear PQC site called the intranuclear quality control site, a poorly understood nuclear inclusion that coordinates dynamic proteome triage decisions in yeast.
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Affiliation(s)
- Arun Kumar
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada; Dept. of Medical Genetics, University of British Columbia, Vancouver Canada
| | - Veena Mathew
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada
| | - Peter C Stirling
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada; Dept. of Medical Genetics, University of British Columbia, Vancouver Canada.
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27
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Ishikawa Y, Nishino S, Fukuda S, Nguyet VTA, Izawa S. Severe ethanol stress induces the preferential synthesis of mitochondrial disaggregase Hsp78 and formation of DUMPs in Saccharomyces cerevisiae. Biochim Biophys Acta Gen Subj 2022; 1866:130147. [DOI: 10.1016/j.bbagen.2022.130147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/24/2022] [Accepted: 04/05/2022] [Indexed: 01/10/2023]
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de Moura Ferreira MA, da Silveira FA, da Silveira WB. Ethanol stress responses in Kluyveromyces marxianus: current knowledge and perspectives. Appl Microbiol Biotechnol 2022; 106:1341-1353. [DOI: 10.1007/s00253-022-11799-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 11/02/2022]
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29
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Borgert L, Mishra S, den Brave F. Quality control of cytoplasmic proteins inside the nucleus. Comput Struct Biotechnol J 2022; 20:4618-4625. [PMID: 36090811 PMCID: PMC9440239 DOI: 10.1016/j.csbj.2022.08.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/13/2022] [Accepted: 08/15/2022] [Indexed: 11/03/2022] Open
Abstract
A complex network of molecular chaperones and proteolytic machinery safeguards the proteins which comprise the proteome, from the time they are synthesized on ribosomes to their destruction via proteolysis. Impaired protein quality control results in the accumulation of aberrant proteins, which may undergo unwanted spurious interactions with other proteins, thereby interfering with a broad range of cellular functions. To protect the cellular environment, such proteins are degraded or sequestered into inclusions in different subcellular compartments. Recent findings demonstrate that aberrant or mistargeted proteins from different cytoplasmic compartments are removed from their environment by transporting them into the nucleus. These proteins are degraded by the nuclear ubiquitin–proteasome system or sequestered into intra-nuclear inclusions. Here, we discuss the emerging role of the nucleus as a cellular quality compartment based on recent findings in the yeast Saccharomyces cerevisiae. We describe the current knowledge on cytoplasmic substrates of nuclear protein quality control, the mechanism of nuclear import of such proteins, as well as possible advantages and risks of nuclear sequestration of aberrant proteins.
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30
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Dannenmaier S, Desroches Altamirano C, Schüler L, Zhang Y, Hummel J, Milanov M, Oeljeklaus S, Koch HG, Rospert S, Alberti S, Warscheid B. Quantitative proteomics identifies the universally conserved ATPase Ola1p as a positive regulator of heat shock response in Saccharomyces cerevisiae. J Biol Chem 2021; 297:101050. [PMID: 34571008 PMCID: PMC8531669 DOI: 10.1016/j.jbc.2021.101050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/24/2021] [Accepted: 08/04/2021] [Indexed: 12/02/2022] Open
Abstract
The universally conserved P-loop ATPase Ola1 is implicated in various cellular stress response pathways, as well as in cancer and tumor progression. However, Ola1p functions are divergent between species, and the involved mechanisms are only poorly understood. Here, we studied the role of Ola1p in the heat shock response of the yeast Saccharomyces cerevisiae using a combination of quantitative and pulse labeling-based proteomics approaches, in vitro studies, and cell-based assays. Our data show that when heat stress is applied to cells lacking Ola1p, the expression of stress-protective proteins is enhanced. During heat stress Ola1p associates with detergent-resistant protein aggregates and rapidly forms assemblies that localize to stress granules. The assembly of Ola1p was also observed in vitro using purified protein and conditions, which resembled those in living cells. We show that loss of Ola1p results in increased protein ubiquitination of detergent-insoluble aggregates recovered from heat-shocked cells. When cells lacking Ola1p were subsequently relieved from heat stress, reinitiation of translation was delayed, whereas, at the same time, de novo synthesis of central factors required for protein refolding and the clearance of aggregates was enhanced when compared with wild-type cells. The combined data suggest that upon acute heat stress, Ola1p is involved in the stabilization of misfolded proteins, which become sequestered in cytoplasmic stress granules. This function of Ola1p enables cells to resume translation in a timely manner as soon as heat stress is relieved.
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Affiliation(s)
- Stefan Dannenmaier
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Lisa Schüler
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ying Zhang
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Johannes Hummel
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Martin Milanov
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Silke Oeljeklaus
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Hans-Georg Koch
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Simon Alberti
- BIOTEC and CMCB, Technische Universität Dresden, Dresden, Germany
| | - Bettina Warscheid
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.
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31
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Reinle K, Mogk A, Bukau B. The Diverse Functions of Small Heat Shock Proteins in the Proteostasis Network. J Mol Biol 2021; 434:167157. [PMID: 34271010 DOI: 10.1016/j.jmb.2021.167157] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 01/21/2023]
Abstract
The protein quality control (PQC) system maintains protein homeostasis by counteracting the accumulation of misfolded protein conformers. Substrate degradation and refolding activities executed by ATP-dependent proteases and chaperones constitute major strategies of the proteostasis network. Small heat shock proteins represent ATP-independent chaperones that bind to misfolded proteins, preventing their uncontrolled aggregation. sHsps share the conserved α-crystallin domain (ACD) and gain functional specificity through variable and largely disordered N- and C-terminal extensions (NTE, CTE). They form large, polydisperse oligomers through multiple, weak interactions between NTE/CTEs and ACD dimers. Sequence variations of sHsps and the large variability of sHsp oligomers enable sHsps to fulfill diverse tasks in the PQC network. sHsp oligomers represent inactive yet dynamic resting states that are rapidly deoligomerized and activated upon stress conditions, releasing substrate binding sites in NTEs and ACDs Bound substrates are usually isolated in large sHsp/substrate complexes. This sequestration activity of sHsps represents a third strategy of the proteostasis network. Substrate sequestration reduces the burden for other PQC components during immediate and persistent stress conditions. Sequestered substrates can be released and directed towards refolding pathways by ATP-dependent Hsp70/Hsp100 chaperones or sorted for degradation by autophagic pathways. sHsps can also maintain the dynamic state of phase-separated stress granules (SGs), which store mRNA and translation factors, by reducing the accumulation of misfolded proteins inside SGs and preventing unfolding of SG components. This ensures SG disassembly and regain of translational capacity during recovery periods.
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Affiliation(s)
- Kevin Reinle
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany; Deutsches Krebsforschungszentrum (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Axel Mogk
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany; Deutsches Krebsforschungszentrum (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
| | - Bernd Bukau
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany; Deutsches Krebsforschungszentrum (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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32
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Ullah M, Qian NPM, Yannarelli G, Akbar A. Heat shock protein 20 promotes sirtuin 1-dependent cell proliferation in induced pluripotent stem cells. World J Stem Cells 2021; 13:659-669. [PMID: 34249234 PMCID: PMC8246253 DOI: 10.4252/wjsc.v13.i6.659] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/27/2021] [Accepted: 05/27/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Heat shock proteins (HSPs) are molecular chaperones that protect cells against cellular stresses or injury. However, it has been increasingly recognized that they also play crucial roles in regulating fundamental cellular processes. HSP20 has been implicated in cell proliferation, but conflicting studies have shown that it can either promote or suppress proliferation. The underlying mechanisms by which HSP20 regulates cell proliferation and pluripotency remain unexplored. While the effect of HSP20 on cell proliferation has been recognized, its role in inducing pluripotency in human-induced pluripotent stem cells (iPSCs) has not been addressed. AIM To evaluate the efficacy of HSP20 overexpression in human iPSCs and evaluate the ability to promote cell proliferation. The purpose of this study was to investigate whether overexpression of HSP20 in iPSCs can increase pluripotency and regeneration. METHODS We used iPSCs, which retain their potential for cell proliferation. HSP20 overexpression effectively enhanced cell proliferation and pluripotency. Overexpression of HSP20 in iPSCs was characterized by immunocytochemistry staining and real-time polymerase chain reaction. We also used cell culture, cell counting, western blotting, and flow cytometry analyses to validate HSP20 overexpression and its mechanism. RESULTS This study demonstrated that overexpression of HSP20 can increase the pluripotency in iPSCs. Furthermore, by overexpressing HSP20 in iPSCs, we showed that HSP20 upregulated proliferation markers, induced pluripotent genes, and drove cell proliferation in a sirtuin 1 (SIRT1)-dependent manner. These data have practical applications in the field of stem cell-based therapies where the mass expansion of cells is needed to generate large quantities of stem cell-derived cells for transplantation purposes. CONCLUSION We found that the overexpression of HSP20 enhanced the proliferation of iPSCs in a SIRT1-dependent manner. Herein, we established the distinct crosstalk between HSP20 and SIRT1 in regulating cell proliferation and pluripotency. Our study provides novel insights into the mechanisms controlling cell proliferation that can potentially be exploited to improve the expansion and pluripotency of human iPSCs for cell transplantation therapies. These results suggest that iPSCs overexpressing HSP20 exert regenerative and proliferative effects and may have the potential to improve clinical outcomes.
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Affiliation(s)
- Mujib Ullah
- Institute for Immunity and Transplantation, Stem Cell Biology and Regenerative Medicine, School of Medicine, Stanford University, Stanford, CA 94304, United States.
| | - Nicole Pek Min Qian
- Immunology and School of Medicine, Stanford University, Stanford, CA 94304, United States
| | - Gustavo Yannarelli
- Laboratorio de Regulación Génica y Células Madre, Instituto de Medicina Traslacional, Trasplante y Bioingeniería (IMeTTyB), Universidad Favaloro-CONICET, Buenos Aires 1078, Argentina
| | - Asma Akbar
- Institute for Molecular Medicine, School of Medicine, Stanford University, Stanford, CA 94304, United States
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33
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Reversible protein aggregation as cytoprotective mechanism against heat stress. Curr Genet 2021; 67:849-855. [PMID: 34091720 PMCID: PMC8592950 DOI: 10.1007/s00294-021-01191-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/24/2021] [Accepted: 04/27/2021] [Indexed: 01/01/2023]
Abstract
Temperature fluctuation is one of the most frequent threats to which organisms are exposed in nature. The activation of gene expression programs that trigger the transcription of heat stress-protective genes is the main cellular response to resist high temperatures. In addition, reversible accumulation and compartmentalization of thermosensitive proteins in high-order molecular assemblies are emerging as critical mechanisms to ensure cellular protection upon heat stress. Here, we summarize representative examples of membrane-less intracellular bodies formed upon heat stress in yeasts and human cells and highlight how protein aggregation can be turned into a cytoprotective mechanism.
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34
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Eisele F, Eisele-Bürger AM, Hao X, Berglund LL, Höög JL, Liu B, Nyström T. An Hsp90 co-chaperone links protein folding and degradation and is part of a conserved protein quality control. Cell Rep 2021; 35:109328. [PMID: 34192536 DOI: 10.1016/j.celrep.2021.109328] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 11/30/2020] [Accepted: 06/09/2021] [Indexed: 10/21/2022] Open
Abstract
In this paper, we show that the essential Hsp90 co-chaperone Sgt1 is a member of a general protein quality control network that links folding and degradation through its participation in the degradation of misfolded proteins both in the cytosol and the endoplasmic reticulum (ER). Sgt1-dependent protein degradation acts in a parallel pathway to the ubiquitin ligase (E3) and ubiquitin chain elongase (E4), Hul5, and overproduction of Hul5 partly suppresses defects in cells with reduced Sgt1 activity. Upon proteostatic stress, Sgt1 accumulates transiently, in an Hsp90- and proteasome-dependent manner, with quality control sites (Q-bodies) of both yeast and human cells that co-localize with Vps13, a protein that creates organelle contact sites. Misfolding disease proteins, such as synphilin-1 involved in Parkinson's disease, are also sequestered to these compartments and require Sgt1 for their clearance.
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Affiliation(s)
- Frederik Eisele
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health - AgeCap, University of Gothenburg, Medicinaregatan 7A, 413 90 Gothenburg, Sweden.
| | - Anna Maria Eisele-Bürger
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health - AgeCap, University of Gothenburg, Medicinaregatan 7A, 413 90 Gothenburg, Sweden; Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, PO Box 7015, 75007 Uppsala, Sweden
| | - Xinxin Hao
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health - AgeCap, University of Gothenburg, Medicinaregatan 7A, 413 90 Gothenburg, Sweden
| | - Lisa Larsson Berglund
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health - AgeCap, University of Gothenburg, Medicinaregatan 7A, 413 90 Gothenburg, Sweden; Department of Chemistry & Molecular Biology, University of Gothenburg, Medicinaregatan 9 C, 413 90 Gothenburg, Sweden
| | - Johanna L Höög
- Department of Chemistry & Molecular Biology, University of Gothenburg, Medicinaregatan 9 C, 413 90 Gothenburg, Sweden
| | - Beidong Liu
- Department of Chemistry & Molecular Biology, University of Gothenburg, Medicinaregatan 9 C, 413 90 Gothenburg, Sweden
| | - Thomas Nyström
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health - AgeCap, University of Gothenburg, Medicinaregatan 7A, 413 90 Gothenburg, Sweden.
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35
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Feder ZA, Ali A, Singh A, Krakowiak J, Zheng X, Bindokas VP, Wolfgeher D, Kron SJ, Pincus D. Subcellular localization of the J-protein Sis1 regulates the heat shock response. J Cell Biol 2021; 220:211600. [PMID: 33326013 PMCID: PMC7748816 DOI: 10.1083/jcb.202005165] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 10/13/2020] [Accepted: 11/06/2020] [Indexed: 12/24/2022] Open
Abstract
Cells exposed to heat shock induce a conserved gene expression program, the heat shock response (HSR), encoding protein homeostasis (proteostasis) factors. Heat shock also triggers proteostasis factors to form subcellular quality control bodies, but the relationship between these spatial structures and the HSR is unclear. Here we show that localization of the J-protein Sis1, a cofactor for the chaperone Hsp70, controls HSR activation in yeast. Under nonstress conditions, Sis1 is concentrated in the nucleoplasm, where it promotes Hsp70 binding to the transcription factor Hsf1, repressing the HSR. Upon heat shock, Sis1 forms an interconnected network with other proteostasis factors that spans the nucleolus and the surface of the endoplasmic reticulum. We propose that localization of Sis1 to this network directs Hsp70 activity away from Hsf1 in the nucleoplasm, leaving Hsf1 free to induce the HSR. In this manner, Sis1 couples HSR activation to the spatial organization of the proteostasis network.
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Affiliation(s)
- Zoë A Feder
- Whitehead Institute for Biomedical Research, Cambridge, MA
| | - Asif Ali
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL
| | - Abhyudai Singh
- Department of Electrical and Computer Engineering, University of Delaware, Newark, DE.,Department of Biomedical Engineering, University of Delaware, Newark, DE.,Department of Mathematical Sciences, University of Delaware, Newark, DE.,Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE
| | | | - Xu Zheng
- Whitehead Institute for Biomedical Research, Cambridge, MA.,State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, China
| | - Vytas P Bindokas
- Integrated Light Microscopy Core Facility, University of Chicago, Chicago, IL
| | - Donald Wolfgeher
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL
| | - Stephen J Kron
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL
| | - David Pincus
- Whitehead Institute for Biomedical Research, Cambridge, MA.,Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL.,Center for Physics of Evolving Systems, University of Chicago, Chicago, IL
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Troussicot L, Burmann BM, Molin M. Structural determinants of multimerization and dissociation in 2-Cys peroxiredoxin chaperone function. Structure 2021; 29:640-654. [PMID: 33945778 DOI: 10.1016/j.str.2021.04.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/31/2021] [Accepted: 04/14/2021] [Indexed: 12/19/2022]
Abstract
Peroxiredoxins (PRDXs) are abundant peroxidases present in all kingdoms of life. Recently, they have been shown to also carry out additional roles as molecular chaperones. To address this emerging supplementary function, this review focuses on structural studies of 2-Cys PRDX systems exhibiting chaperone activity. We provide a detailed understanding of the current knowledge of structural determinants underlying the chaperone function of PRDXs. Specifically, we describe the mechanisms which may modulate their quaternary structure to facilitate interactions with client proteins and how they are coordinated with the functions of other molecular chaperones. Following an overview of PRDX molecular architecture, we outline structural details of the presently best-characterized peroxiredoxins exhibiting chaperone function and highlight common denominators. Finally, we discuss the remarkable structural similarities between 2-Cys PRDXs, small HSPs, and J-domain-independent Hsp40 holdases in terms of their functions and dynamic equilibria between low- and high-molecular-weight oligomers.
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Affiliation(s)
- Laura Troussicot
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Björn M Burmann
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden.
| | - Mikael Molin
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden; Department of Biology and Biological Engineering, Chalmers University of Technology, 405 30 Göteborg, Sweden.
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Edskes HK, Stroobant EE, DeWilde MP, Bezsonov EE, Wickner RB. Proteasome Control of [URE3] Prion Propagation by Degradation of Anti-Prion Proteins Cur1 and Btn2 in Saccharomyces cerevisiae. Genetics 2021; 218:6179111. [PMID: 33742650 DOI: 10.1093/genetics/iyab037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 02/27/2021] [Indexed: 01/16/2023] Open
Abstract
[URE3] is a prion of the nitrogen catabolism controller, Ure2p, and [PSI+] is a prion of the translation termination factor Sup35p in S. cerevisiae. Btn2p cures [URE3] by sequestration of Ure2p amyloid filaments. Cur1p, paralogous to Btn2p, also cures [URE3], but by a different (unknown) mechanism. We find that an array of mutations impairing proteasome assembly or MG132 inhibition of proteasome activity result in loss of [URE3]. In proportion to their prion-curing effects, each mutation affecting proteasomes elevates the cellular concentration of the anti-prion proteins Btn2 and Cur1. Of >4,600 proteins detected by SILAC, Btn2p was easily the most overexpressed in a pre9Δ (α3 core subunit) strain. Indeed, deletion of BTN2 and CUR1 prevents the prion-curing effects of proteasome impairment. Surprisingly, the 15 most unstable yeast proteins are not increased in pre9Δ cells suggesting altered proteasome specificity rather than simple inactivation. Hsp42, a chaperone that cooperates with Btn2 and Cur1 in curing [URE3], is also necessary for the curing produced by proteasome defects, although Hsp42p levels are not substantially altered by a proteasome defect. We find that pre9Δ and proteasome chaperone mutants that most efficiently lose [URE3], do not destabilize [PSI+] or alter cellular levels of Sup35p. A tof2 mutation or deletion likewise destabilizes [URE3], and elevates Btn2p, suggesting that Tof2p deficiency inactivates proteasomes. We suggest that when proteasomes are saturated with denatured/misfolded proteins, their reduced degradation of Btn2p and Cur1p automatically upregulates these aggregate-handling systems to assist in the clean-up.
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Affiliation(s)
- Herman K Edskes
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA
| | - Emily E Stroobant
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA
| | - Morgan P DeWilde
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA
| | - Evgeny E Bezsonov
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA
| | - Reed B Wickner
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA
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Acquired Resistance to Severe Ethanol Stress in Saccharomyces cerevisiae Protein Quality Control. Appl Environ Microbiol 2021; 87:AEM.02353-20. [PMID: 33361368 DOI: 10.1128/aem.02353-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/14/2020] [Indexed: 12/11/2022] Open
Abstract
Acute severe ethanol stress (10% [vol/vol]) damages proteins and causes the intracellular accumulation of insoluble proteins in Saccharomyces cerevisiae On the other hand, a pretreatment with mild stress increases tolerance to subsequent severe stress, which is called acquired stress resistance. It currently remains unclear whether the accumulation of insoluble proteins under severe ethanol stress may be mitigated by increasing protein quality control (PQC) activity in cells pretreated with mild stress. In the present study, we examined the induction of resistance to severe ethanol stress in PQC and confirmed that a pretreatment with 6% (vol/vol) ethanol or mild thermal stress at 37°C significantly reduced insoluble protein levels and the aggregation of Lsg1, which is prone to denaturation and aggregation by stress, in yeast cells under 10% (vol/vol) ethanol stress. The induction of this stress resistance required the new synthesis of proteins; the expression of proteins comprising the bichaperone system (Hsp104, Ssa3, and Fes1), Sis1, and Hsp42 was upregulated during the pretreatment and maintained under subsequent severe ethanol stress. Since the pretreated cells of deficient mutants in the bichaperone system (fes1Δ hsp104Δ and ssa2Δ ssa3Δ ssa4Δ) failed to sufficiently reduce insoluble protein levels and Lsg1 aggregation, the enhanced activity of the bichaperone system appears to be important for the induction of adequate stress resistance. In contrast, the importance of proteasomes and aggregases (Btn2 and Hsp42) in the induction of stress resistance has not been confirmed. These results provide further insights into the PQC activity of yeast cells under severe ethanol stress, including the brewing process.IMPORTANCE Although the budding yeast S. cerevisiae, which is used in the production of alcoholic beverages and bioethanol, is highly tolerant of ethanol, high concentrations of ethanol are also stressful to the yeast and cause various adverse effects, including protein denaturation. A pretreatment with mild stress improves the ethanol tolerance of yeast cells; however, it currently remains unclear whether it increases PQC activity and reduces the levels of denatured proteins. In the present study, we found that a pretreatment with mild ethanol upregulated the expression of proteins involved in PQC and mitigated the accumulation of insoluble proteins, even under severe ethanol stress. These results provide novel insights into ethanol tolerance and the adaptive capacity of yeast. They may also contribute to research on the physiology of yeast cells during the brewing process, in which the concentration of ethanol gradually increases.
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Alberti S, Hyman AA. Biomolecular condensates at the nexus of cellular stress, protein aggregation disease and ageing. Nat Rev Mol Cell Biol 2021; 22:196-213. [PMID: 33510441 DOI: 10.1038/s41580-020-00326-6] [Citation(s) in RCA: 625] [Impact Index Per Article: 156.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2020] [Indexed: 12/14/2022]
Abstract
Biomolecular condensates are membraneless intracellular assemblies that often form via liquid-liquid phase separation and have the ability to concentrate biopolymers. Research over the past 10 years has revealed that condensates play fundamental roles in cellular organization and physiology, and our understanding of the molecular principles, components and forces underlying their formation has substantially increased. Condensate assembly is tightly regulated in the intracellular environment, and failure to control condensate properties, formation and dissolution can lead to protein misfolding and aggregation, which are often the cause of ageing-associated diseases. In this Review, we describe the mechanisms and regulation of condensate assembly and dissolution, highlight recent advances in understanding the role of biomolecular condensates in ageing and disease, and discuss how cellular stress, ageing-related loss of homeostasis and a decline in protein quality control may contribute to the formation of aberrant, disease-causing condensates. Our improved understanding of condensate pathology provides a promising path for the treatment of protein aggregation diseases.
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Affiliation(s)
- Simon Alberti
- Technische Universität Dresden, Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Engineering (CMCB), Dresden, Germany.
| | - Anthony A Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
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40
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Nuclear Ubiquitin-Proteasome Pathways in Proteostasis Maintenance. Biomolecules 2021; 11:biom11010054. [PMID: 33406777 PMCID: PMC7824755 DOI: 10.3390/biom11010054] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/28/2020] [Accepted: 12/30/2020] [Indexed: 12/19/2022] Open
Abstract
Protein homeostasis, or proteostasis, is crucial for the functioning of a cell, as proteins that are mislocalized, present in excessive amounts, or aberrant due to misfolding or other type of damage can be harmful. Proteostasis includes attaining the correct protein structure, localization, and the formation of higher order complexes, and well as the appropriate protein concentrations. Consequences of proteostasis imbalance are evident in a range of neurodegenerative diseases characterized by protein misfolding and aggregation, such as Alzheimer's, Parkinson's, and amyotrophic lateral sclerosis. To protect the cell from the accumulation of aberrant proteins, a network of protein quality control (PQC) pathways identifies the substrates and direct them towards refolding or elimination via regulated protein degradation. The main pathway for degradation of misfolded proteins is the ubiquitin-proteasome system. PQC pathways have been first described in the cytoplasm and the endoplasmic reticulum, however, accumulating evidence indicates that the nucleus is an important PQC compartment for ubiquitination and proteasomal degradation of not only nuclear, but also cytoplasmic proteins. In this review, we summarize the nuclear ubiquitin-proteasome pathways involved in proteostasis maintenance in yeast, focusing on inner nuclear membrane-associated degradation (INMAD) and San1-mediated protein quality control.
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Abstract
The heat shock response (HSR) is a gene expression program that protects cells from heat and proteotoxic stressors. In this issue, Feder et al. (2020. J. Cell Biol.https://doi.org/10.1083/jcb.202005165) show that subcellular relocalization of the cochaperone Sis1 drives the HSR by de-suppressing the transcription factor Hsf1.
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Affiliation(s)
| | - Onn Brandman
- Department of Biochemistry, Stanford University, Stanford, CA
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42
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Boronat S, Cabrera M, Hidalgo E. Spatial sequestration of misfolded proteins as an active chaperone-mediated process during heat stress. Curr Genet 2021; 67:237-243. [PMID: 33386485 DOI: 10.1007/s00294-020-01135-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 01/05/2023]
Abstract
Under thermal stress, different protein quality control (PQC) strategies are activated to maintain an intact proteome, which may vary from one model system to another. Hence thermo-sensitive proteins that lose their active conformation might be refolded with the aid of chaperones or removed by the ubiquitin-proteasome system or the process of autophagy. We have recently developed thermo-sensitive reporters to study PQC in fission yeast and shown the relevance of a third adaptation strategy: the sequestration of misfolded proteins into inclusions which will prevent a rapid degradation and allow the refolding once stress ends. These protein inclusions, protein aggregate centers (PACs), contain a broad spectrum of misfolding/aggregation-prone proteins and chaperones involved in their assembly or dissolution. The chaperone couple Mas5/Ssa2 plays a crucial role in PAC formation, whereas the Hsp104 chaperone promotes their disassembly. The absence of aggregates observed in cells lacking Mas5 could be also explained by the activation of the transcription factor Hsf1 and the induction of chaperone genes, we have excluded this possibility here demonstrating that increased Hsf1 activity and the subsequent overexpression of chaperones do not prevent the assembly of protein aggregates. Protein deposition at certain locations also constitutes a tactic to inactivate proteins temporally. This is the case of Pyp1, the main phosphatase of the stress response kinase Sty1. Upon stress imposition, misfolded Pyp1 is sequestered into cytosolic protein foci while active Sty1 at the nucleus switches on the transcriptional response. In conclusion, we propose that the assembly of aggregation-like foci, PACs in fission yeast, is a crucial PQC strategy during heat stress, and that the Hsp40 chaperone Mas5 is required for PAC assembly and connects physiological and heat-shock triggered PQC.
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Affiliation(s)
- Susanna Boronat
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Dr. Aiguader 88, 08003, Barcelona, Spain
| | - Margarita Cabrera
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Dr. Aiguader 88, 08003, Barcelona, Spain
| | - Elena Hidalgo
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Dr. Aiguader 88, 08003, Barcelona, Spain.
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Mathew V, Kumar A, Jiang YK, West K, Tam AS, Stirling PC. Cdc48 regulates intranuclear quality control sequestration of the Hsh155 splicing factor in budding yeast. J Cell Sci 2020; 133:jcs.252551. [PMID: 33172985 DOI: 10.1242/jcs.252551] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/30/2020] [Indexed: 11/20/2022] Open
Abstract
Cdc48 (known as VCP in mammals) is a highly conserved ATPase chaperone that plays an essential role in the assembly and disassembly of protein-DNA complexes and in degradation of misfolded proteins. We find that in Saccharomyces cerevisiae budding yeast, Cdc48 accumulates during cellular stress at intranuclear protein quality control sites (INQ). We show that Cdc48 function is required to suppress INQ formation under non-stress conditions and to promote recovery following genotoxic stress. Cdc48 physically associates with the INQ substrate and splicing factor Hsh155, and regulates its assembly with partner proteins. Accordingly, cdc48 mutants have defects in splicing and show spontaneous distribution of Hsh155 to INQ aggregates, where it is stabilized. Overall, this study shows that Cdc48 regulates deposition of proteins at INQ and suggests a previously unknown role for Cdc48 in the regulation or stabilization of splicing subcomplexes.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Veena Mathew
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Arun Kumar
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver V6H 3N1, Canada
| | - Yangyang K Jiang
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Kyra West
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Annie S Tam
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver V6H 3N1, Canada
| | - Peter C Stirling
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada .,Department of Medical Genetics, University of British Columbia, Vancouver V6H 3N1, Canada
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44
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Kohler V, Andréasson C. Hsp70-mediated quality control: should I stay or should I go? Biol Chem 2020; 401:1233-1248. [PMID: 32745066 DOI: 10.1515/hsz-2020-0187] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/11/2020] [Indexed: 12/30/2022]
Abstract
Chaperones of the 70 kDa heat shock protein (Hsp70) superfamily are key components of the cellular proteostasis system. Together with its co-chaperones, Hsp70 forms proteostasis subsystems that antagonize protein damage during physiological and stress conditions. This function stems from highly regulated binding and release cycles of protein substrates, which results in a flow of unfolded, partially folded and misfolded species through the Hsp70 subsystem. Specific factors control how Hsp70 makes decisions regarding folding and degradation fates of the substrate proteins. In this review, we summarize how the flow of Hsp70 substrates is controlled in the cell with special emphasis on recent advances regarding substrate release mechanisms.
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Affiliation(s)
- Verena Kohler
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, S-106 91 Stockholm, Sweden
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, S-106 91 Stockholm, Sweden
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45
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Releasing the Lockdown: An Emerging Role for the Ubiquitin-Proteasome System in the Breakdown of Transient Protein Inclusions. Biomolecules 2020; 10:biom10081168. [PMID: 32784966 PMCID: PMC7463783 DOI: 10.3390/biom10081168] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 08/06/2020] [Accepted: 08/08/2020] [Indexed: 12/20/2022] Open
Abstract
Intracellular protein inclusions are diverse cellular entities with distinct biological properties. They vary in their protein content, sequestration sites, physiological function, conditions for their generation, and turnover rates. Major distinctions have been recognized between stationary amyloids and dynamic, misfolded protein deposits. The former being a dead end for irreversibly misfolded proteins, hence, cleared predominantly by autophagy, while the latter consists of a protein-quality control mechanism, important for cell endurance, where proteins are sequestered during proteotoxic stress and resolved upon its relief. Accordingly, the disaggregation of transient inclusions is a regulated process consisting of protein solubilization, followed by a triage step to either refolding or to ubiquitin-mediated degradation. Recent studies have demonstrated an indispensable role in disaggregation for components of the chaperone and the ubiquitin-proteasome systems. These include heat-shock chaperones of the 40/70/100 kDa families, the proteasome, proteasome substrate shuttling factors, and deubiquitylating enzymes. Thus, a functional link has been established between the chaperone machinery that extracts proteins from transient deposits and 26S proteasome-dependent disaggregation, indicative of a coordinated process. In this review, we discuss data emanating from these important studies and subsequently consolidate the information in the form of a working model for the disaggregation mechanism.
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46
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Andreotti DZ, Silva JDN, Matumoto AM, Orellana AM, de Mello PS, Kawamoto EM. Effects of Physical Exercise on Autophagy and Apoptosis in Aged Brain: Human and Animal Studies. Front Nutr 2020; 7:94. [PMID: 32850930 PMCID: PMC7399146 DOI: 10.3389/fnut.2020.00094] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 05/22/2020] [Indexed: 12/13/2022] Open
Abstract
The aging process is characterized by a series of molecular and cellular changes over the years that could culminate in the deterioration of physiological parameters important to keeping an organism alive and healthy. Physical exercise, defined as planned, structured and repetitive physical activity, has been an important force to alter physiology and brain development during the process of human beings' evolution. Among several aspects of aging, the aim of this review is to discuss the balance between two vital cellular processes such as autophagy and apoptosis, based on the fact that physical exercise as a non-pharmacological strategy seems to rescue the imbalance between autophagy and apoptosis during aging. Therefore, the effects of different types or modalities of physical exercise in humans and animals, and the benefits of each of them on aging, will be discussed as a possible preventive strategy against neuronal death.
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Affiliation(s)
- Diana Zukas Andreotti
- Laboratory of Molecular and Functional Neurobiology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Josiane do Nascimento Silva
- Laboratory of Molecular and Functional Neurobiology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Amanda Midori Matumoto
- Laboratory of Molecular and Functional Neurobiology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Ana Maria Orellana
- Laboratory of Molecular Neuropharmacology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Paloma Segura de Mello
- Laboratory of Molecular Neuropharmacology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Elisa Mitiko Kawamoto
- Laboratory of Molecular and Functional Neurobiology, Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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47
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Wickner RB, Edskes HK, Son M, Wu S, Niznikiewicz M. How Do Yeast Cells Contend with Prions? Int J Mol Sci 2020; 21:ijms21134742. [PMID: 32635197 PMCID: PMC7369894 DOI: 10.3390/ijms21134742] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 12/11/2022] Open
Abstract
Infectious proteins (prions) include an array of human (mammalian) and yeast amyloid diseases in which a protein or peptide forms a linear β-sheet-rich filament, at least one functional amyloid prion, and two functional infectious proteins unrelated to amyloid. In Saccharomyces cerevisiae, at least eight anti-prion systems deal with pathogenic amyloid yeast prions by (1) blocking their generation (Ssb1,2, Ssz1, Zuo1), (2) curing most variants as they arise (Btn2, Cur1, Hsp104, Upf1,2,3, Siw14), and (3) limiting the pathogenicity of variants that do arise and propagate (Sis1, Lug1). Known mechanisms include facilitating proper folding of the prion protein (Ssb1,2, Ssz1, Zuo1), producing highly asymmetric segregation of prion filaments in mitosis (Btn2, Hsp104), competing with the amyloid filaments for prion protein monomers (Upf1,2,3), and regulation of levels of inositol polyphosphates (Siw14). It is hoped that the discovery of yeast anti-prion systems and elucidation of their mechanisms will facilitate finding analogous or homologous systems in humans, whose manipulation may be useful in treatment.
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48
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den Brave F, Cairo LV, Jagadeesan C, Ruger-Herreros C, Mogk A, Bukau B, Jentsch S. Chaperone-Mediated Protein Disaggregation Triggers Proteolytic Clearance of Intra-nuclear Protein Inclusions. Cell Rep 2020; 31:107680. [PMID: 32492414 PMCID: PMC7273177 DOI: 10.1016/j.celrep.2020.107680] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 04/02/2020] [Accepted: 04/30/2020] [Indexed: 12/31/2022] Open
Abstract
The formation of insoluble inclusions in the cytosol and nucleus is associated with impaired protein homeostasis and is a hallmark of several neurodegenerative diseases. Due to the absence of the autophagic machinery, nuclear protein aggregates require a solubilization step preceding degradation by the 26S proteasome. Using yeast, we identify a nuclear protein quality control pathway required for the clearance of protein aggregates. The nuclear J-domain protein Apj1 supports protein disaggregation together with Hsp70 but independent of the canonical disaggregase Hsp104. Disaggregation mediated by Apj1/Hsp70 promotes turnover rather than refolding. A loss of Apj1 activity uncouples disaggregation from proteasomal turnover, resulting in accumulation of toxic soluble protein species. Endogenous substrates of the Apj1/Hsp70 pathway include both nuclear and cytoplasmic proteins, which aggregate inside the nucleus upon proteotoxic stress. These findings demonstrate the coordinated activity of the Apj1/Hsp70 disaggregation system with the 26S proteasome in facilitating the clearance of toxic inclusions inside the nucleus.
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Affiliation(s)
- Fabian den Brave
- Department of Molecular Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
| | - Lucas V Cairo
- Department of Molecular Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany; Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Chandhuru Jagadeesan
- Department of Molecular Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany; Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Carmen Ruger-Herreros
- Center for Molecular Biology of Heidelberg University (ZMBH), Im Neuenheimer Feld 282, DKFZ-ZMBH Alliance, Heidelberg, Germany; German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Axel Mogk
- Center for Molecular Biology of Heidelberg University (ZMBH), Im Neuenheimer Feld 282, DKFZ-ZMBH Alliance, Heidelberg, Germany; German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH), Im Neuenheimer Feld 282, DKFZ-ZMBH Alliance, Heidelberg, Germany; German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Stefan Jentsch
- Department of Molecular Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
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49
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Nachman E, Wentink AS, Madiona K, Bousset L, Katsinelos T, Allinson K, Kampinga H, McEwan WA, Jahn TR, Melki R, Mogk A, Bukau B, Nussbaum-Krammer C. Disassembly of Tau fibrils by the human Hsp70 disaggregation machinery generates small seeding-competent species. J Biol Chem 2020; 295:9676-9690. [PMID: 32467226 PMCID: PMC7363153 DOI: 10.1074/jbc.ra120.013478] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 05/17/2020] [Indexed: 12/14/2022] Open
Abstract
The accumulation of amyloid Tau aggregates is implicated in Alzheimer's disease (AD) and other tauopathies. Molecular chaperones are known to maintain protein homeostasis. Here, we show that an ATP-dependent human chaperone system disassembles Tau fibrils in vitro We found that this function is mediated by the core chaperone HSC70, assisted by specific cochaperones, in particular class B J-domain proteins and a heat shock protein 110 (Hsp110)-type nucleotide exchange factor (NEF). The Hsp70 disaggregation machinery processed recombinant fibrils assembled from all six Tau isoforms as well as Sarkosyl-resistant Tau aggregates extracted from cell cultures and human AD brain tissues, demonstrating the ability of the Hsp70 machinery to recognize a broad range of Tau aggregates. However, the chaperone activity released monomeric and small oligomeric Tau species, which induced the aggregation of self-propagating Tau conformers in a Tau cell culture model. We conclude that the activity of the Hsp70 disaggregation machinery is a double-edged sword, as it eliminates Tau amyloids at the cost of generating new seeds.
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Affiliation(s)
- Eliana Nachman
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany.,Schaller Research Group Proteostasis in Neurodegenerative Disease of Heidelberg University and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Anne S Wentink
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Karine Madiona
- Institute Francois Jacob (MIRCen), CEA, and Laboratory of Neurodegenerative Diseases, CNRS, Fontenay-Aux-Roses, France
| | - Luc Bousset
- Institute Francois Jacob (MIRCen), CEA, and Laboratory of Neurodegenerative Diseases, CNRS, Fontenay-Aux-Roses, France
| | - Taxiarchis Katsinelos
- Department of Clinical Neurosciences, UK Dementia Research Institute at the University of Cambridge, Cambridge, United Kingdom
| | - Kieren Allinson
- Department of Neuropathology, Cambridge Universities Hospital Trust, Cambridge, United Kingdom
| | - Harm Kampinga
- Department of Biomedical Science of Cell and System, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - William A McEwan
- Department of Clinical Neurosciences, UK Dementia Research Institute at the University of Cambridge, Cambridge, United Kingdom
| | - Thomas R Jahn
- Schaller Research Group Proteostasis in Neurodegenerative Disease of Heidelberg University and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ronald Melki
- Institute Francois Jacob (MIRCen), CEA, and Laboratory of Neurodegenerative Diseases, CNRS, Fontenay-Aux-Roses, France
| | - Axel Mogk
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Carmen Nussbaum-Krammer
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
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Neuromuscular Diseases Due to Chaperone Mutations: A Review and Some New Results. Int J Mol Sci 2020; 21:ijms21041409. [PMID: 32093037 PMCID: PMC7073051 DOI: 10.3390/ijms21041409] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 12/12/2022] Open
Abstract
Skeletal muscle and the nervous system depend on efficient protein quality control, and they express chaperones and cochaperones at high levels to maintain protein homeostasis. Mutations in many of these proteins cause neuromuscular diseases, myopathies, and hereditary motor and sensorimotor neuropathies. In this review, we cover mutations in DNAJB6, DNAJB2, αB-crystallin (CRYAB, HSPB5), HSPB1, HSPB3, HSPB8, and BAG3, and discuss the molecular mechanisms by which they cause neuromuscular disease. In addition, previously unpublished results are presented, showing downstream effects of BAG3 p.P209L on DNAJB6 turnover and localization.
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