|
1
|
Wang X, Liu Z, Xu X, Wang X, Ming Z, Liu C, Gao H, Li T, Liang Q. KSHV hijacks the antiviral kinase IKKε to initiate lytic replication. PLoS Pathog 2025; 21:e1012856. [PMID: 39823515 PMCID: PMC11781660 DOI: 10.1371/journal.ppat.1012856] [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: 07/30/2024] [Revised: 01/30/2025] [Accepted: 12/23/2024] [Indexed: 01/19/2025] Open
Abstract
IKKε is a traditional antiviral kinase known for positively regulating the production of type I interferon (IFN) and the expression of IFN-stimulated genes (ISGs) during various virus infections. However, through an inhibitor screen targeting cellular kinases, we found that IKKε plays a crucial role in the lytic replication of Kaposi's sarcoma-associated herpesvirus (KSHV). Mechanistically, during KSHV lytic replication, IKKε undergoes significant SUMOylation at both Lys321 and Lys549 by the viral SUMO E3 ligase ORF45. This SUMOylation event leads to the association of IKKε with PML, resulting in the disruption of PML nuclear bodies (PML NBs) and subsequent increase in lytic replication of KSHV. Notably, IKKε does not affect the total expression level of PML but facilitates the translocation of PML from the nucleus to the cytoplasm during KSHV lytic replication. Further experiments utilizing mutations on the SUMOylation sites of IKKε or inhibiting IKKε using BAY-985 showed that these actions no longer impact PML NBs and completely suppress the lytic replication of KSHV. These findings not only emphasize the essential role of IKKε in the life cycle of KSHV but also illustrate how KSHV exploits IKKε through SUMOylation modification to enhance its own replication process.
Collapse
Affiliation(s)
- Xiaoqian Wang
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Joint Ph.D. Degree Program between SJTU-SM and HUJI-MED, Shanghai Jiao Tong University, Shanghai, China
| | - Zhenshan Liu
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xue Xu
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xin Wang
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zizhen Ming
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chengrong Liu
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hang Gao
- Department of Bone and Joint Surgery, Orthopaedic Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Tingting Li
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, Laboratory of Animal Nutrition and Human Health, Hunan Provincial Key Laboratory of Animal Intestinal Function and Regulation, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Qiming Liang
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| |
Collapse
|
|
2
|
Singhal J, Madan E, Chaurasiya A, Srivastava P, Singh N, Kaushik S, Kahlon AK, Maurya MK, Marothia M, Joshi P, Ranganathan A, Singh S. Host SUMOylation Pathway Negatively Regulates Protective Immune Responses and Promotes Leishmania donovani Survival. Front Cell Infect Microbiol 2022; 12:878136. [PMID: 35734580 PMCID: PMC9207379 DOI: 10.3389/fcimb.2022.878136] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/19/2022] [Indexed: 11/25/2022] Open
Abstract
SUMOylation is one of the post-translational modifications that have recently been described as a key regulator of various cellular, nuclear, metabolic, and immunological processes. The process of SUMOylation involves the modification of one or more lysine residues of target proteins by conjugation of a ubiquitin-like, small polypeptide known as SUMO for their degradation, stability, transcriptional regulation, cellular localization, and transport. Herein, for the first time, we report the involvement of the host SUMOylation pathway in the process of infection of Leishmania donovani, a causative agent of visceral leishmaniasis. Our data revealed that infection of L. donovani to the host macrophages leads to upregulation of SUMOylation pathway genes and downregulation of a deSUMOylating gene, SENP1. Further, to confirm the effect of the host SUMOylation on the growth of Leishmania, the genes associated with the SUMOylation pathway were silenced and parasite load was analyzed. The knockdown of the SUMOylation pathway led to a reduction in parasitic load, suggesting the role of the host SUMOylation pathway in the disease progression and parasite survival. Owing to the effect of the SUMOylation pathway in autophagy, we further investigated the status of host autophagy to gain mechanistic insights into how SUMOylation mediates the regulation of growth of L. donovani. Knockdown of genes of host SUMOylation pathway led to the reduction of the expression levels of host autophagy markers while promoting autophagosome–lysosome fusion, suggesting SUMOylation-mediated autophagy in terms of autophagy initiation and autophagy maturation during parasite survival. The levels of reactive oxygen species (ROS) generation, nitric oxide (NO) production, and pro-inflammatory cytokines were also elevated upon the knockdown of genes of the host SUMOylation pathway during L. donovani infection. This indicates the involvement of the SUMOylation pathway in the modulation of protective immune responses and thus favoring parasite survival. Taken together, the results of this study indicate the hijacking of the host SUMOylation pathway by L. donovani toward the suppression of host immune responses and facilitation of host autophagy to potentially facilitate its survival. Targeting of SUMOylation pathway can provide a starting point for the design and development of novel therapeutic interventions to combat leishmaniasis.
Collapse
Affiliation(s)
- Jhalak Singhal
- *Correspondence: Jhalak Singhal, ; Anand Ranganathan, ; Shailja Singh,
| | | | | | | | | | | | | | | | | | | | - Anand Ranganathan
- *Correspondence: Jhalak Singhal, ; Anand Ranganathan, ; Shailja Singh,
| | - Shailja Singh
- *Correspondence: Jhalak Singhal, ; Anand Ranganathan, ; Shailja Singh,
| |
Collapse
|
|
3
|
Fan Y, Li X, Zhang L, Zong Z, Wang F, Huang J, Zeng L, Zhang C, Yan H, Zhang L, Zhou F. SUMOylation in Viral Replication and Antiviral Defense. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104126. [PMID: 35060688 PMCID: PMC8895153 DOI: 10.1002/advs.202104126] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 12/07/2021] [Indexed: 05/22/2023]
Abstract
SUMOylation is a ubiquitination-like post-translational modification that plays an essential role in the regulation of protein function. Recent studies have shown that proteins from both RNA and DNA virus families can be modified by SUMO conjugation, which facilitates viral replication. Viruses can manipulate the entire process of SUMOylation through interplay with the SUMO pathway. By contrast, SUMOylation can eliminate viral infection by regulating host antiviral immune components. A deeper understanding of how SUMOylation regulates viral proteins and cellular antiviral components is necessary for the development of effective antiviral therapies. In the present review, the regulatory mechanism of SUMOylation in viral replication and infection and the antiviral immune response, and the consequences of this regulation for viral replication and engagement with antiviral innate immunity are summarized. The potential therapeutic applications of SUMOylation in diseases caused by viruses are also discussed.
Collapse
Affiliation(s)
- Yao Fan
- Department of PharmacologyZhejiang University City College School of MedicineHangzhouZhejiang310015China
- Institutes of Biology and Medical ScienceSoochow UniversitySuzhou215123China
| | - Xiang Li
- MOE Laboratory of Biosystems Homeostasis and Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhou310058China
| | - Lei Zhang
- Department of Orthopaedic SurgeryThe Third Affiliated Hospital of Wenzhou Medical UniversityRui'an325200China
| | - Zhi Zong
- MOE Laboratory of Biosystems Homeostasis and Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhou310058China
| | - Fangwei Wang
- MOE Laboratory of Biosystems Homeostasis and Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhou310058China
| | - Jun Huang
- MOE Laboratory of Biosystems Homeostasis and Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhou310058China
| | - Linghui Zeng
- Department of PharmacologyZhejiang University City College School of MedicineHangzhouZhejiang310015China
| | - Chong Zhang
- Department of PharmacologyZhejiang University City College School of MedicineHangzhouZhejiang310015China
| | - Haiyan Yan
- Department of PharmacologyZhejiang University City College School of MedicineHangzhouZhejiang310015China
| | - Long Zhang
- MOE Laboratory of Biosystems Homeostasis and Protection and Innovation Center for Cell Signaling NetworkLife Sciences InstituteZhejiang UniversityHangzhou310058China
| | - Fangfang Zhou
- Institutes of Biology and Medical ScienceSoochow UniversitySuzhou215123China
| |
Collapse
|
|
4
|
Liu Z, Liu C, Wang X, Li W, Zhou J, Dong P, Xiao MZX, Wang C, Zhang Y, Fu J, Zhu F, Liang Q. RSK1 SUMOylation is required for KSHV lytic replication. PLoS Pathog 2021; 17:e1010123. [PMID: 34871326 PMCID: PMC8675914 DOI: 10.1371/journal.ppat.1010123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/16/2021] [Accepted: 11/16/2021] [Indexed: 01/01/2023] Open
Abstract
RSK1, a downstream kinase of the MAPK pathway, has been shown to regulate multiple cellular processes and is essential for lytic replication of a variety of viruses, including Kaposi's sarcoma-associated herpesvirus (KSHV). Besides phosphorylation, it is not known whether other post-translational modifications play an important role in regulating RSK1 function. We demonstrate that RSK1 undergoes robust SUMOylation during KSHV lytic replication at lysine residues K110, K335, and K421. SUMO modification does not alter RSK1 activation and kinase activity upon KSHV ORF45 co-expression, but affects RSK1 downstream substrate phosphorylation. Compared to wild-type RSK1, the overall phosphorylation level of RxRxxS*/T* motif is significantly declined in RSK1K110/335/421R expressing cells. Specifically, SUMOylation deficient RSK1 cannot efficiently phosphorylate eIF4B. Sequence analysis showed that eIF4B has one SUMO-interacting motif (SIM) between the amino acid position 166 and 170 (166IRVDV170), which mediates the association between eIF4B and RSK1 through SUMO-SIM interaction. These results indicate that SUMOylation regulates the phosphorylation of RSK1 downstream substrates, which is required for efficient KSHV lytic replication.
Collapse
Affiliation(s)
- Zhenshan Liu
- Research Center of Translational Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chengrong Liu
- Research Center of Translational Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xin Wang
- Research Center of Translational Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wenwei Li
- Department of Biological Science, Florida State University, Tallahassee, Flordia, United States of America
| | - Jingfan Zhou
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Peixian Dong
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Maggie Z. X. Xiao
- Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Chunxia Wang
- Department of Critical Care Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Yucai Zhang
- Department of Critical Care Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Joyce Fu
- Department of Statistics, University of California, Riverside, Riverside, California, United States of America
| | - Fanxiu Zhu
- Department of Biological Science, Florida State University, Tallahassee, Flordia, United States of America
- * E-mail: (FZ); (QL)
| | - Qiming Liang
- Research Center of Translational Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
- * E-mail: (FZ); (QL)
| |
Collapse
|
|
5
|
Patra U, Müller S. A Tale of Usurpation and Subversion: SUMO-Dependent Integrity of Promyelocytic Leukemia Nuclear Bodies at the Crossroad of Infection and Immunity. Front Cell Dev Biol 2021; 9:696234. [PMID: 34513832 PMCID: PMC8430037 DOI: 10.3389/fcell.2021.696234] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 07/30/2021] [Indexed: 12/13/2022] Open
Abstract
Promyelocytic leukemia nuclear bodies (PML NBs) are multi-protein assemblies representing distinct sub-nuclear structures. As phase-separated molecular condensates, PML NBs exhibit liquid droplet-like consistency. A key organizer of the assembly and dynamics of PML NBs is the ubiquitin-like SUMO modification system. SUMO is covalently attached to PML and other core components of PML NBs thereby exhibiting a glue-like function by providing multivalent interactions with proteins containing SUMO interacting motifs (SIMs). PML NBs serve as the catalytic center for nuclear SUMOylation and SUMO-SIM interactions are essential for protein assembly within these structures. Importantly, however, formation of SUMO chains on PML and other PML NB-associated proteins triggers ubiquitylation and proteasomal degradation which coincide with disruption of these nuclear condensates. To date, a plethora of nuclear activities such as transcriptional and post-transcriptional regulation of gene expression, apoptosis, senescence, cell cycle control, DNA damage response, and DNA replication have been associated with PML NBs. Not surprisingly, therefore, SUMO-dependent PML NB integrity has been implicated in regulating many physiological processes including tumor suppression, metabolism, drug-resistance, development, cellular stemness, and anti-pathogen immune response. The interplay between PML NBs and viral infection is multifaceted. As a part of the cellular antiviral defense strategy, PML NB components are crucial restriction factors for many viruses and a mutual positive correlation has been found to exist between PML NBs and the interferon response. Viruses, in turn, have developed counterstrategies for disarming PML NB associated immune defense measures. On the other end of the spectrum, certain viruses are known to usurp specific PML NB components for successful replication and disruption of these sub-nuclear foci has recently been linked to the stimulation rather than curtailment of antiviral gene repertoire. Importantly, the ability of invading virions to manipulate the host SUMO modification machinery is essential for this interplay between PML NB integrity and viruses. Moreover, compelling evidence is emerging in favor of bacterial pathogens to negotiate with the SUMO system thereby modulating PML NB-directed intrinsic and innate immunity. In the current context, we will present an updated account of the dynamic intricacies between cellular PML NBs as the nuclear SUMO modification hotspots and immune regulatory mechanisms in response to viral and bacterial pathogens.
Collapse
Affiliation(s)
- Upayan Patra
- Institute of Biochemistry II, Faculty of Medicine, Goethe University, Frankfurt, Germany
| | - Stefan Müller
- Institute of Biochemistry II, Faculty of Medicine, Goethe University, Frankfurt, Germany
| |
Collapse
|
|
6
|
STUB1 is targeted by the SUMO-interacting motif of EBNA1 to maintain Epstein-Barr Virus latency. PLoS Pathog 2020; 16:e1008447. [PMID: 32176739 PMCID: PMC7105294 DOI: 10.1371/journal.ppat.1008447] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/30/2020] [Accepted: 03/01/2020] [Indexed: 12/31/2022] Open
Abstract
Latent Epstein-Barr virus (EBV) infection is strongly associated with several malignancies, including B-cell lymphomas and epithelial tumors. EBNA1 is a key antigen expressed in all EBV-associated tumors during latency that is required for maintenance of the EBV episome DNA and the regulation of viral gene transcription. However, the mechanism utilized by EBV to maintain latent infection at the levels of posttranslational regulation remains largely unclear. Here, we report that EBNA1 contains two SUMO-interacting motifs (SIM2 and SIM3), and mutation of SIM2, but not SIM3, dramatically disrupts the EBNA1 dimerization, while SIM3 contributes to the polySUMO2 modification of EBNA1 at lysine 477 in vitro. Proteomic and immunoprecipitation analyses further reveal that the SIM3 motif is required for the EBNA1-mediated inhibitory effects on SUMO2-modified STUB1, SUMO2-mediated degradation of USP7, and SUMO1-modified KAP1. Deletion of the EBNASIM motif leads to functional loss of both EBNA1-mediated viral episome maintenance and lytic gene silencing. Importantly, hypoxic stress induces the SUMO2 modification of EBNA1, and in turn the dissociation of EBNA1 with STUB1, KAP1 and USP7 to increase the SUMO1 modification of both STUB1 and KAP1 for reactivation of lytic replication. Therefore, the EBNA1SIM motif plays an essential role in EBV latency and is a potential therapeutic target against EBV-associated cancers. The Small Ubiquitin-related modifier (SUMO) modification of proteins is a reversible post-translational regulation involved in control of gene transcription, among other functions. Epstein-Barr virus (EBV) infects most people worldwide and contributes to the development of several types of cancers due to its ability to induce cell proliferation and survival. EBNA1 is expressed in all forms of EBV-associated tumors. In this study, we found that EBNA1 contains a SUMO-interacting motif (SIM) named EBNA1SIM, which is required for EBNA1 to exert inhibitory effects on a SUMO2-modified complex (SC2) including STUB1, KAP1 and USP7. Disruption of EBNA1SIM leads to loss of both EBNA1-mediated viral episome maintenance and lytic gene silencing. Importantly, hypoxia-mediated reactivation of viral lytic replication induces the EBNA1 dissociation from STUB1 in the SC2 complex. This discovery not only opens a new insight on the interplay between host and virus, but it also provides a therapeutic target specific against EBV-associated cancers.
Collapse
|
|
7
|
Koch S, Damas M, Freise A, Hage E, Dhingra A, Rückert J, Gallo A, Kremmer E, Tegge W, Brönstrup M, Brune W, Schulz TF. Kaposi's sarcoma-associated herpesvirus vIRF2 protein utilizes an IFN-dependent pathway to regulate viral early gene expression. PLoS Pathog 2019; 15:e1007743. [PMID: 31059555 PMCID: PMC6522069 DOI: 10.1371/journal.ppat.1007743] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 05/16/2019] [Accepted: 03/31/2019] [Indexed: 12/14/2022] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV; human herpesvirus 8) belongs to the subfamily of Gammaherpesvirinae and is the etiological agent of Kaposi’s sarcoma as well as of two lymphoproliferative diseases: primary effusion lymphoma and multicentric Castleman disease. The KSHV life cycle is divided into a latent and a lytic phase and is highly regulated by viral immunomodulatory proteins which control the host antiviral immune response. Among them is a group of proteins with homology to cellular interferon regulatory factors, the viral interferon regulatory factors 1–4. The KSHV vIRFs are known as inhibitors of cellular interferon signaling and are involved in different oncogenic pathways. Here we characterized the role of the second vIRF protein, vIRF2, during the KSHV life cycle. We found the vIRF2 protein to be expressed in different KSHV positive cells with early lytic kinetics. Importantly, we observed that vIRF2 suppresses the expression of viral early lytic genes in both newly infected and reactivated persistently infected endothelial cells. This vIRF2-dependent regulation of the KSHV life cycle might involve the increased expression of cellular interferon-induced genes such as the IFIT proteins 1, 2 and 3, which antagonize the expression of early KSHV lytic proteins. Our findings suggest a model in which the viral protein vIRF2 allows KSHV to harness an IFN-dependent pathway to regulate KSHV early gene expression. The life cycle of Kaposi Sarcoma herpesvirus involves both persistence in a latent form and productive replication to generate new viral particles. How the virus switches between latency and productive (‘lytic’) replication is only partially understood. Here we show that a viral homologue of interferon regulatory factors, vIRF2, antagonizes lytic protein expression in endothelial cells. It does this by inducing the expression of cellular interferon-regulated genes such as IFIT 1–3, which in turn dampens early viral gene expression. This observation suggests that vIRF2 allows KSHV to harness the interferon pathway to regulate early viral gene expression in endothelial cells.
Collapse
Affiliation(s)
- Sandra Koch
- Hannover Medical School, Institute of Virology, Hannover, Germany
- German Centre for Infection Research, Hannover-Braunschweig Site, Germany
| | - Modester Damas
- Hannover Medical School, Institute of Virology, Hannover, Germany
- German Centre for Infection Research, Hannover-Braunschweig Site, Germany
| | - Anika Freise
- Hannover Medical School, Institute of Virology, Hannover, Germany
- German Centre for Infection Research, Hannover-Braunschweig Site, Germany
| | - Elias Hage
- Hannover Medical School, Institute of Virology, Hannover, Germany
- German Centre for Infection Research, Hannover-Braunschweig Site, Germany
| | - Akshay Dhingra
- Hannover Medical School, Institute of Virology, Hannover, Germany
- German Centre for Infection Research, Hannover-Braunschweig Site, Germany
| | - Jessica Rückert
- Hannover Medical School, Institute of Virology, Hannover, Germany
- German Centre for Infection Research, Hannover-Braunschweig Site, Germany
| | - Antonio Gallo
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- German Centre for Infection Research, Hamburg Site, Germany
| | - Elisabeth Kremmer
- Institute of Molecular Immunology, Helmholtz Centre Munich, German Research Center for Environmental Health, Munich, Germany
| | - Werner Tegge
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Mark Brönstrup
- German Centre for Infection Research, Hannover-Braunschweig Site, Germany
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Wolfram Brune
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- German Centre for Infection Research, Hamburg Site, Germany
| | - Thomas F. Schulz
- Hannover Medical School, Institute of Virology, Hannover, Germany
- German Centre for Infection Research, Hannover-Braunschweig Site, Germany
- * E-mail:
| |
Collapse
|
|
8
|
de la Cruz-Herrera CF, Baz-Martínez M, Motiam AE, Vidal S, Collado M, Vidal A, Rodríguez MS, Esteban M, Rivas C. Phosphorylable tyrosine residue 162 in the double-stranded RNA-dependent kinase PKR modulates its interaction with SUMO. Sci Rep 2017; 7:14055. [PMID: 29070839 PMCID: PMC5656663 DOI: 10.1038/s41598-017-12777-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 09/14/2017] [Indexed: 12/21/2022] Open
Abstract
Activated dsRNA-dependent serine/threonine kinase PKR phosphorylates the alpha subunit of eukaryotic initiation factor 2 (eIF2α), resulting in a shut-off of general translation, induction of apoptosis, and inhibition of virus replication. PKR can be activated by binding to dsRNA or cellular proteins such as PACT/RAX, or by its conjugation to ISG15 or SUMO. Here, we demonstrate that PKR also interacts with SUMO in a non-covalent manner. We identify the phosphorylable tyrosine residue 162 in PKR (Y162) as a modulator of the PKR-SUMO non-covalent interaction as well as of the PKR SUMOylation. Finally, we show that the efficient SUMO-mediated eIF2α phosphorylation and inhibition of protein synthesis induced by PKR in response to dsRNA depend on this residue. In summary, our data identify a new mechanism of regulation of PKR activity and reinforce the relevance of both, tyrosine phosphorylation and SUMO interaction in controlling the activity of PKR.
Collapse
Affiliation(s)
- Carlos F de la Cruz-Herrera
- Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología-CSIC, Darwin 3, Madrid, 28049, Spain. .,Department of Molecular Genetics, University of Toronto, 1 Kings College Circle, Toronto, M5S 1A8, Canada.
| | - Maite Baz-Martínez
- Centro de Investigación en Medicina Molecular (CIMUS), Universidade de Santiago de Compostela, Instituto de Investigaciones Sanitarias (IDIS), Santiago de Compostela, E15706, Spain
| | - Ahmed El Motiam
- Centro de Investigación en Medicina Molecular (CIMUS), Universidade de Santiago de Compostela, Instituto de Investigaciones Sanitarias (IDIS), Santiago de Compostela, E15706, Spain
| | - Santiago Vidal
- Centro de Investigación en Medicina Molecular (CIMUS), Universidade de Santiago de Compostela, Instituto de Investigaciones Sanitarias (IDIS), Santiago de Compostela, E15706, Spain
| | - Manuel Collado
- Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), SERGAS, Santiago de Compostela, E15706, Spain
| | - Anxo Vidal
- Departamento de Fisioloxía and Centro de Investigación en Medicina Molecular (CIMUS), Universidade de Santiago de Compostela, Instituto de Investigaciones Sanitarias (IDIS), Santiago de Compostela, E15782, Spain
| | - Manuel S Rodríguez
- Advanced Technology Institute in Life Sciences (ITAV) CNRS-USR3505, 31106, Université de Toulouse, UPS, Toulouse, France.,Institut de Pharmacologie et de Biologie Structurale (IPBS) CNRS-UMR5089, 31077, Université de Toulouse, UPS, Toulouse, France
| | - Mariano Esteban
- Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología-CSIC, Darwin 3, Madrid, 28049, Spain
| | - Carmen Rivas
- Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología-CSIC, Darwin 3, Madrid, 28049, Spain. .,Centro de Investigación en Medicina Molecular (CIMUS), Universidade de Santiago de Compostela, Instituto de Investigaciones Sanitarias (IDIS), Santiago de Compostela, E15706, Spain.
| |
Collapse
|
|
9
|
Gammaherpesviral Tegument Proteins, PML-Nuclear Bodies and the Ubiquitin-Proteasome System. Viruses 2017; 9:v9100308. [PMID: 29065450 PMCID: PMC5691659 DOI: 10.3390/v9100308] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/18/2017] [Accepted: 10/20/2017] [Indexed: 12/13/2022] Open
Abstract
Gammaherpesviruses like Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) subvert the ubiquitin proteasome system for their own benefit in order to facilitate viral gene expression and replication. In particular, viral tegument proteins that share sequence homology to the formylglycineamide ribonucleotide amidotransferase (FGARAT, or PFAS), an enzyme in the cellular purine biosynthesis, are important for disrupting the intrinsic antiviral response associated with Promyelocytic Leukemia (PML) protein-associated nuclear bodies (PML-NBs) by proteasome-dependent and independent mechanisms. In addition, all herpesviruses encode for a potent ubiquitin protease that can efficiently remove ubiquitin chains from proteins and thereby interfere with several different cellular pathways. In this review, we discuss mechanisms and functional consequences of virus-induced ubiquitination and deubiquitination for early events in gammaherpesviral infection.
Collapse
|
|
10
|
Wilson VG. Viral Interplay with the Host Sumoylation System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 963:359-388. [PMID: 28197923 PMCID: PMC7121812 DOI: 10.1007/978-3-319-50044-7_21] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Viruses have evolved elaborate means to regulate diverse cellular pathways in order to create a cellular environment that facilitates viral survival and reproduction. This includes enhancing viral macromolecular synthesis and assembly, as well as preventing antiviral responses, including intrinsic, innate, and adaptive immunity. There are numerous mechanisms by which viruses mediate their effects on the host cell, and this includes targeting various cellular post-translational modification systems, including sumoylation. The wide-ranging impact of sumoylation on cellular processes such as transcriptional regulation, apoptosis, stress response, and cell cycle control makes it an attractive target for viral dysregulation. To date, proteins from both RNA and DNA virus families have been shown to be modified by SUMO conjugation, and this modification appears critical for viral protein function. More interestingly, members of the several viral families have been shown to modulate sumoylation, including papillomaviruses, adenoviruses, herpesviruses, orthomyxoviruses, filoviruses, and picornaviruses. This chapter will focus on mechanisms by which sumoylation both impacts human viruses and is used by viruses to promote viral infection and disease.
Collapse
Affiliation(s)
- Van G Wilson
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center, 8447 HWY 47, Bryan, TX, 77807-1359, USA.
| |
Collapse
|
|
11
|
The Latency-Associated Nuclear Antigen of Kaposi's Sarcoma-Associated Herpesvirus Inhibits Expression of SUMO/Sentrin-Specific Peptidase 6 To Facilitate Establishment of Latency. J Virol 2017; 91:JVI.00806-17. [PMID: 28615201 DOI: 10.1128/jvi.00806-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 05/15/2017] [Indexed: 11/20/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV), which belongs to the Gammaherpesviridae, typically displays two different phases in its life cycle, the latent phase and the lytic phase. Latency-associated nuclear antigen (LANA), the primary viral product during latency, has been reported to bind to a series of cellular gene promoters to modulate gene transcription. To systemically elucidate the cellular genes regulated by LANA, we identified genome-wide LANA binding sites by chromatin immunoprecipitation coupled with sequencing (ChIP-seq). We stratified ChIP-seq data and found that LANA might be involved in the macromolecule catabolic process. Specifically, we found and verified that LANA could directly bind to the promoter of the SUMO/sentrin-specific peptidase 6 (SENP6) gene in vivo and in vitro LANA could repress SENP6 promoter activity in a dose-dependent manner in a reporter gene assay. LANA expression was sufficient to inhibit endogenous SENP6 expression at both the RNA and protein levels. Moreover, SENP6 overexpression in KSHV-infected cells reduced LANA at the protein level. Mechanistically, we found that SENP6 could interact with LANA and reduce the formation of sumoylated LANA, which relies on the desumoylation ability of SENP6. During de novo infection, SENP6 overexpression would decrease the abundance of LANA and enhance viral gene expression, which would hamper the establishment of latency. Taken together, these data suggest that KSHV-encoded LANA could inhibit SENP6 expression to regulate the abundance of itself, which may play an important role in controlling the establishment of latency.IMPORTANCE LANA, as a key latent protein produced by KSHV, is responsible for episome persistence and regulates viral reactivation. In the present study, our results demonstrated that LANA could bind to the promoter region of the SENP6 gene and inhibit SENP6 expression while the regulated SENP6 could in turn modulate the abundance of LANA through desumoylation. This delicate regulation may provide important insights to explain the abundance of LANA during KSHV latency.
Collapse
|
|
12
|
Koch S, Schulz TF. Rhadinoviral interferon regulatory factor homologues. Biol Chem 2017; 398:857-870. [PMID: 28455950 DOI: 10.1515/hsz-2017-0111] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/20/2017] [Indexed: 01/17/2023]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8 (HHV8) is a gammaherpesvirus and the etiological agent of Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman disease. The KSHV genome contains genes for a unique group of proteins with homology to cellular interferon regulatory factors, termed viral interferon regulatory factors (vIRFs). This review will give an overview over the oncogenic, antiapoptotic and immunomodulatory characteristics of KSHV and related vIRFs.
Collapse
|
|
13
|
Wang J, Guo Y, Wang X, Zhao R, Wang Y. Modulation of global SUMOylation by Kaposi's sarcoma-associated herpesvirus and its effects on viral gene expression. J Med Virol 2017. [PMID: 28639696 DOI: 10.1002/jmv.24882] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Some viruses have evolved to exploit the host SUMOylation system to regulate their own replication. Kaposi's sarcoma-associated herpesvirus (KSHV) encodes K-bZIP, a SUMO E3 ligase catalyzing the SUMOylation of viral and host proteins. KSHV also encodes replication and transcriptional activator (RTA), a SUMO-targeted ubiquitin ligase catalyzing the ubiquitination of SUMOylated proteins and targeting them for degradation. Using chronic KSHV-infected TRE × BCBL-1 RTA cells, the expression kinetics of K-bZIP and RTA, and the global SUMOylation level were detected. The endogenous K-bZIP protein increased dramatically after the induction of the RTA gene that is tetracycline responsive, but then decreased rapidly after peaking at 8 h post tetracycline treatment. Consistently, the global SUMO-conjugated proteins increased and remained at high levels until 8 h, and decreased afterward, correlating with the expression kinetics of RTA and K-bZIP. In luciferase reporter assays, transfection of 293T cells with SUMO2 expression plasmid reduced the RTA transactivations of immediate-early genes k8, orf45, and orf50, but enhanced the RTA transactivations of other viral genes including orf57, pan, k2, orf8, and orf73. These results indicated that KSHV might regulate gene expression and viral replication schedule through modulation of the global SUMOylation level, probably via RTA, and RTA-regulated K-bZIP.
Collapse
Affiliation(s)
- Jinzhong Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, China
| | - Yuying Guo
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Xu Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Rui Zhao
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Ying Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, China
| |
Collapse
|
|
14
|
SUMO Modification Stabilizes Enterovirus 71 Polymerase 3D To Facilitate Viral Replication. J Virol 2016; 90:10472-10485. [PMID: 27630238 DOI: 10.1128/jvi.01756-16] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 09/04/2016] [Indexed: 12/15/2022] Open
Abstract
Accumulating evidence suggests that viruses hijack cellular proteins to circumvent the host immune system. Ubiquitination and SUMOylation are extensively studied posttranslational modifications (PTMs) that play critical roles in diverse biological processes. Cross talk between ubiquitination and SUMOylation of both host and viral proteins has been reported to result in distinct functional consequences. Enterovirus 71 (EV71), an RNA virus belonging to the family Picornaviridae, is a common cause of hand, foot, and mouth disease. Little is known concerning how host PTM systems interact with enteroviruses. Here, we demonstrate that the 3D protein, an RNA-dependent RNA polymerase (RdRp) of EV71, is modified by small ubiquitin-like modifier 1 (SUMO-1) both during infection and in vitro Residues K159 and L150/D151/L152 were responsible for 3D SUMOylation as determined by bioinformatics prediction combined with site-directed mutagenesis. Also, primer-dependent polymerase assays indicated that mutation of SUMOylation sites impaired 3D polymerase activity and virus replication. Moreover, 3D is ubiquitinated in a SUMO-dependent manner, and SUMOylation is crucial for 3D stability, which may be due to the interplay between the two PTMs. Importantly, increasing the level of SUMO-1 in EV71-infected cells augmented the SUMOylation and ubiquitination levels of 3D, leading to enhanced replication of EV71. These results together suggested that SUMO and ubiquitin cooperatively regulated EV71 infection, either by SUMO-ubiquitin hybrid chains or by ubiquitin conjugating to the exposed lysine residue through SUMOylation. Our study provides new insight into how a virus utilizes cellular pathways to facilitate its replication. IMPORTANCE Infection with enterovirus 71 (EV71) often causes neurological diseases in children, and EV71 is responsible for the majority of fatalities. Based on a better understanding of interplay between virus and host cell, antiviral drugs against enteroviruses may be developed. As a dynamic cellular process of posttranslational modification, SUMOylation regulates global cellular protein localization, interaction, stability, and enzymatic activity. However, little is known concerning how SUMOylation directly influences virus replication by targeting viral polymerase. Here, we found that EV71 polymerase 3D was SUMOylated during EV71 infection and in vitro Moreover, the SUMOylation sites were determined, and in vitro polymerase assays indicated that mutations at SUMOylation sites could impair polymerase synthesis. Importantly, 3D is ubiquitinated in a SUMOylation-dependent manner that enhances the stability of the viral polymerase. Our findings indicate that the two modifications likely cooperatively enhance virus replication. Our study may offer a new therapeutic strategy against virus replication.
Collapse
|
|
15
|
Gan J, Qiao N, Strahan R, Zhu C, Liu L, Verma SC, Wei F, Cai Q. Manipulation of ubiquitin/SUMO pathways in human herpesviruses infection. Rev Med Virol 2016; 26:435-445. [DOI: 10.1002/rmv.1900] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 07/03/2016] [Accepted: 07/25/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Jin Gan
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College; Fudan University; Shanghai China
| | - Niu Qiao
- Department of Medical Systems Biology, School of Basic Medical Sciences; Department of Translational Medicine, Shanghai Public Health Clinical Center; Institutes of Biomedical Sciences, Fudan University; Shanghai China
| | - Roxanne Strahan
- Department of Microbiology & Immunology; University of Nevada, Reno School of Medicine; Reno NV USA
| | - Caixia Zhu
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College; Fudan University; Shanghai China
| | - Lei Liu
- Department of Medical Systems Biology, School of Basic Medical Sciences; Department of Translational Medicine, Shanghai Public Health Clinical Center; Institutes of Biomedical Sciences, Fudan University; Shanghai China
| | - Subhash C. Verma
- Department of Microbiology & Immunology; University of Nevada, Reno School of Medicine; Reno NV USA
| | - Fang Wei
- ShengYushou Center of Cell Biology and Immunology, School of Life Sciences and Biotechnology; Shanghai Jiao Tong University; Shanghai China
| | - Qiliang Cai
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College; Fudan University; Shanghai China
| |
Collapse
|
|
16
|
Chang PC, Campbell M, Robertson ES. Human Oncogenic Herpesvirus and Post-translational Modifications - Phosphorylation and SUMOylation. Front Microbiol 2016; 7:962. [PMID: 27379086 PMCID: PMC4911386 DOI: 10.3389/fmicb.2016.00962] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 06/03/2016] [Indexed: 01/05/2023] Open
Abstract
Pathogens, especially viruses, evolve abilities to utilize cellular machineries to facilitate their survival and propagation. Post-translational modifications (PTMs), especially phosphorylation and SUMOylation, that reversibly modulate the function and interactions of target proteins are among the most important features in cell signaling pathways. PTM-dependent events also serve as one of the favorite targets for viruses. Among the seven unambiguous human oncogenic viruses, hepatitis B virus (HBV), hepatitis C virus (HCV), Epstein-Barr virus (EBV), Kaposi's sarcoma-associated herpesvirus (KSHV), human papillomavirus (HPV), Human T lymphotrophic virus-1 (HTLV-1), and Merkel cell polyomavirus (MCPyV), two are herpesviruses. The life cycle of herpesviruses consists of latent and lytic phases and the rapid switch between these states includes global remodeling of the viral genome from heterochromatin-to-euchromatin. The balance between lytic replication and latency is essential for herpesvirus to maintain a persistent infection through a combination of viral propagation and evasion of the host immune response, which consequently may contribute to tumorigenesis. It is no surprise that the swift reversibility of PTMs, especially SUMOylation, a modification that epigenetically regulates chromatin structure, is a major hijack target of the host for oncogenic herpesviruses. In this brief review, we summarize the varied ways in which herpesviruses engage the host immune components through PTMs, focusing on phosphorylation and SUMOylation.
Collapse
Affiliation(s)
- Pei-Ching Chang
- Institute of Microbiology and Immunology, National Yang-Ming UniversityTaipei, China
- *Correspondence: Pei-Ching Chang, ; Erle S. Robertson,
| | - Mel Campbell
- UC Davis Cancer Center, University of California, Davis, DavisCA, USA
| | - Erle S. Robertson
- Department of Otorhinolaryngology and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, PhiladelphiaPA, USA
- *Correspondence: Pei-Ching Chang, ; Erle S. Robertson,
| |
Collapse
|
|
17
|
Laura MV, de la Cruz-Herrera CF, Ferreirós A, Baz-Martínez M, Lang V, Vidal A, Muñoz-Fontela C, Rodríguez MS, Collado M, Rivas C. KSHV latent protein LANA2 inhibits sumo2 modification of p53. Cell Cycle 2015; 14:277-82. [PMID: 25607652 DOI: 10.4161/15384101.2014.980657] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Tumor suppressor p53 plays a crucial antiviral role and targeting of p53 by viral proteins is a common mechanism involved in virus oncogenesis. The activity of p53 is tightly regulated at the post-translational levels through a myriad of modifications. Among them, modification of p53 by SUMO has been associated with the onset of cellular senescence. Kaposi´s sarcoma-associated herpesvirus (KSHV) expresses several proteins targeting p53, including the latent protein LANA2 that regulates polyubiquitylation and phosphorylation of p53. Here we show that LANA2 also inhibits the modification of p53 by SUMO2. Furthermore, we show that the reduction of p53-SUMO2 conjugation by LANA2, as well as the p53-LANA2 interaction, both require the SUMOylation of the viral protein and its interaction with SUMO or SUMOylated proteins in a non-covalent manner. Finally, we show that the control of p53-SUMO2 conjugation by LANA2 correlates with its ability to inhibit SUMO2- and type I interferon-induced senescence. These results highlight the importance of p53 SUMOylation in the control of virus infection and suggest that viral oncoproteins could contribute to viral infection and cell transformation by abrogating p53 SUMOylation.
Collapse
Affiliation(s)
- Marcos-Villar Laura
- a Department of Molecular and Cellular Biology; Centro Nacional de Biotecnología-CSIC ; Madrid , Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
|
18
|
Kaposi's Sarcoma-Associated Herpesvirus Viral Interferon Regulatory Factor 1 Interacts with a Member of the Interferon-Stimulated Gene 15 Pathway. J Virol 2015; 89:11572-83. [PMID: 26355087 DOI: 10.1128/jvi.01482-15] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/01/2015] [Indexed: 12/26/2022] Open
Abstract
UNLABELLED Kaposi's sarcoma-associated herpesvirus (KSHV) is a gammaherpesvirus known to establish lifelong latency in the human host. We and others have previously shown that three KSHV homologs of cellular interferon regulatory factors (IRFs), known as viral IRFs (vIRFs), participate in evasion of the host interferon (IFN) response. We report that vIRF1 interacts with the cellular interferon-stimulated gene 15 (ISG15) E3 ligase, HERC5, in the context of Toll-like receptor 3 (TLR3) activation and IFN induction. The ISG15 protein is covalently conjugated to target proteins upon activation of the interferon response. Interaction between vIRF1 and HERC5 was confirmed by immunoprecipitation, and the region between amino acids 224 and 349 of vIRF1 was required for interaction with HERC5. We further report that expression of vIRF1 in the context of TLR3 activation results in decreased ISG15 conjugation of proteins. Specifically, TLR3-induced ISG15 conjugation and protein levels of cellular IRF3, a known ISG15 target, were decreased in the presence of vIRF1 compared to the control. vIRF1 itself was also identified as a target of ISG15 conjugation. KSHV-infected cells exhibited increased ISG15 conjugation upon reactivation from latency in coordination with increased IFN. Furthermore, knockdown of ISG15 in latently infected cells resulted in a higher level of KSHV reactivation and an increase in infectious virus. These data suggest that the KSHV vIRF1 protein affects ISG15 conjugation and interferon responses and may contribute to effective KSHV replication. IMPORTANCE The KSHV vIRF1 protein can inhibit interferon activation in response to viral infection. We identified a cellular protein named HERC5, which is the major ligase for ISG15, as a vIRF1 binding partner. vIRF1 association with HERC5 altered ISG15 modification of cellular proteins, and knockdown of ISG15 augmented reactivation of KSHV from latency.
Collapse
|
|
19
|
Kumari P, Narayanan S, Kumar H. Herpesviruses: interfering innate immunity by targeting viral sensing and interferon pathways. Rev Med Virol 2015; 25:187-201. [DOI: 10.1002/rmv.1836] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/03/2015] [Accepted: 03/04/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Puja Kumari
- Laboratory of Immunology, Department of Biological Sciences; Indian Institute of Science Education and Research (IISER); Bhopal India
| | - Sathish Narayanan
- Laboratory of Virology, Department of Biological Sciences; Indian Institute of Science Education and Research (IISER); Bhopal India
| | - Himanshu Kumar
- Laboratory of Immunology, Department of Biological Sciences; Indian Institute of Science Education and Research (IISER); Bhopal India
- Laboratory of Host Defense; WPI Immunology Frontier Research Centre, Osaka University; Osaka Japan
| |
Collapse
|
|
20
|
Chang PC, Kung HJ. SUMO and KSHV Replication. Cancers (Basel) 2014; 6:1905-24. [PMID: 25268162 PMCID: PMC4276950 DOI: 10.3390/cancers6041905] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 09/09/2014] [Accepted: 09/10/2014] [Indexed: 02/07/2023] Open
Abstract
Small Ubiquitin-related MOdifier (SUMO) modification was initially identified as a reversible post-translational modification that affects the regulation of diverse cellular processes, including signal transduction, protein trafficking, chromosome segregation, and DNA repair. Increasing evidence suggests that the SUMO system also plays an important role in regulating chromatin organization and transcription. It is thus not surprising that double-stranded DNA viruses, such as Kaposi's sarcoma-associated herpesvirus (KSHV), have exploited SUMO modification as a means of modulating viral chromatin remodeling during the latent-lytic switch. In addition, SUMO regulation allows the disassembly and assembly of promyelocytic leukemia protein-nuclear bodies (PML-NBs), an intrinsic antiviral host defense, during the viral replication cycle. Overcoming PML-NB-mediated cellular intrinsic immunity is essential to allow the initial transcription and replication of the herpesvirus genome after de novo infection. As a consequence, KSHV has evolved a way as to produce multiple SUMO regulatory viral proteins to modulate the cellular SUMO environment in a dynamic way during its life cycle. Remarkably, KSHV encodes one gene product (K-bZIP) with SUMO-ligase activities and one gene product (K-Rta) that exhibits SUMO-targeting ubiquitin ligase (STUbL) activity. In addition, at least two viral products are sumoylated that have functional importance. Furthermore, sumoylation can be modulated by other viral gene products, such as the viral protein kinase Orf36. Interference with the sumoylation of specific viral targets represents a potential therapeutic strategy when treating KSHV, as well as other oncogenic herpesviruses. Here, we summarize the different ways KSHV exploits and manipulates the cellular SUMO system and explore the multi-faceted functions of SUMO during KSHV's life cycle and pathogenesis.
Collapse
Affiliation(s)
- Pei-Ching Chang
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei 112, Taiwan.
| | - Hsing-Jien Kung
- Institute for Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 110, Taiwan.
| |
Collapse
|
|
21
|
Günther T, Schreiner S, Dobner T, Tessmer U, Grundhoff A. Influence of ND10 components on epigenetic determinants of early KSHV latency establishment. PLoS Pathog 2014; 10:e1004274. [PMID: 25033267 PMCID: PMC4102598 DOI: 10.1371/journal.ppat.1004274] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 06/05/2014] [Indexed: 12/15/2022] Open
Abstract
We have previously demonstrated that acquisition of intricate patterns of activating (H3K4me3, H3K9/K14ac) and repressive (H3K27me3) histone modifications is a hallmark of KSHV latency establishment. The precise molecular mechanisms that shape the latent histone modification landscape, however, remain unknown. Promyelocytic leukemia nuclear bodies (PML-NB), also called nuclear domain 10 (ND10), have emerged as mediators of innate immune responses that can limit viral gene expression via chromatin based mechanisms. Consequently, although ND10 functions thus far have been almost exclusively investigated in models of productive herpesvirus infection, it has been proposed that they also may contribute to the establishment of viral latency. Here, we report the first systematic study of the role of ND10 during KSHV latency establishment, and link alterations in the subcellular distribution of ND10 components to a temporal analysis of histone modification acquisition and host cell gene expression during the early infection phase. Our study demonstrates that KSHV infection results in a transient interferon response that leads to induction of the ND10 components PML and Sp100, but that repression by ND10 bodies is unlikely to contribute to KSHV latency establishment. Instead, we uncover an unexpected role for soluble Sp100 protein, which is efficiently and permanently relocalized from nucleoplasmic and chromatin-associated fractions into the insoluble matrix. We show that LANA expression is sufficient to induce Sp100 relocalization, likely via mediating SUMOylation of Sp100. Furthermore, we demonstrate that depletion of soluble Sp100 occurs precisely when repressive H3K27me3 marks first accumulate on viral genomes, and that knock-down of Sp100 (but not PML or Daxx) facilitates H3K27me3 acquisition. Collectively, our data support a model in which non-ND10 resident Sp100 acts as a negative regulator of polycomb repressive complex-2 (PRC2) recruitment, and suggest that KSHV may actively escape ND10 silencing mechanisms to promote establishment of latent chromatin.
Collapse
Affiliation(s)
- Thomas Günther
- Research Group Virus Genomics, Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Sabrina Schreiner
- Research Unit Viral Transformation, Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Thomas Dobner
- Research Unit Viral Transformation, Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Uwe Tessmer
- Research Group Virus Genomics, Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Adam Grundhoff
- Research Group Virus Genomics, Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| |
Collapse
|
|
22
|
Full F, Jungnickl D, Reuter N, Bogner E, Brulois K, Scholz B, Stürzl M, Myoung J, Jung JU, Stamminger T, Ensser A. Kaposi's sarcoma associated herpesvirus tegument protein ORF75 is essential for viral lytic replication and plays a critical role in the antagonization of ND10-instituted intrinsic immunity. PLoS Pathog 2014; 10:e1003863. [PMID: 24453968 PMCID: PMC3894210 DOI: 10.1371/journal.ppat.1003863] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 11/18/2013] [Indexed: 01/08/2023] Open
Abstract
Nuclear domain 10 (ND10) components are restriction factors that inhibit herpesviral replication. Effector proteins of different herpesviruses can antagonize this restriction by a variety of strategies, including degradation or relocalization of ND10 proteins. We investigated the interplay of Kaposi's Sarcoma-Associated Herpesvirus (KSHV) infection and cellular defense by nuclear domain 10 (ND10) components. Knock-down experiments in primary human cells show that KSHV-infection is restricted by the ND10 components PML and Sp100, but not by ATRX. After KSHV infection, ATRX is efficiently depleted and Daxx is dispersed from ND10, indicating that these two ND10 components can be antagonized by KSHV. We then identified the ORF75 tegument protein of KSHV as the viral factor that induces the disappearance of ATRX and relocalization of Daxx. ORF75 belongs to a viral protein family (viral FGARATs) that has homologous proteins in all gamma-herpesviruses. Isolated expression of ORF75 in primary cells induces a relocalization of PML and dispersal of Sp100, indicating that this viral effector protein is able to influence multiple ND10 components. Moreover, by constructing a KSHV mutant harboring a stop codon at the beginning of ORF75, we could demonstrate that ORF75 is absolutely essential for viral replication and the initiation of viral immediate-early gene expression. Using recombinant viruses either carrying Flag- or YFP-tagged variants of ORF75, we could further corroborate the role of ORF75 in the antagonization of ND10-mediated intrinsic immunity, and show that it is independent of the PML antagonist vIRF3. Members of the viral FGARAT family target different ND10 components, suggesting that the ND10 targets of viral FGARAT proteins have diversified during evolution. We assume that overcoming ND10 intrinsic defense constitutes a critical event in the replication of all herpesviruses; on the other hand, restriction of herpesviral replication by ND10 components may also promote latency as the default outcome of infection.
Collapse
Affiliation(s)
- Florian Full
- Institute for Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Doris Jungnickl
- Institute for Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Nina Reuter
- Institute for Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Elke Bogner
- Institut für Medizinische Virologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Kevin Brulois
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Brigitte Scholz
- Institute for Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Stürzl
- Division of Molecular and Experimental Surgery, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jinjong Myoung
- Novartis Institutes for Biomedical Research, Emeryville, California, United States of America
| | - Jae U. Jung
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Thomas Stamminger
- Institute for Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Armin Ensser
- Institute for Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- * E-mail:
| |
Collapse
|
|
23
|
Rivera-Molina YA, Martínez FP, Tang Q. Nuclear domain 10 of the viral aspect. World J Virol 2013; 2:110-122. [PMID: 24255882 PMCID: PMC3832855 DOI: 10.5501/wjv.v2.i3.110] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Revised: 05/31/2013] [Accepted: 07/11/2013] [Indexed: 02/05/2023] Open
Abstract
Nuclear domain 10 (ND10) are spherical bodies distributed throughout the nucleoplasm and measuring around 0.2-1.0 μm. First observed under an electron microscope, they were originally described as dense bodies found in the nucleus. They are known by a number of other names, including Promyelocytic Leukemia bodies (PML bodies), Kremer bodies, and PML oncogenic domains. ND10 are frequently associated with Cajal bodies and cleavage bodies. It has been suggested that they play a role in regulating gene transcription. ND10 were originally characterized using human autoantisera, which recognizes Speckled Protein of 100 kDa, from patients with primary biliary cirrhosis. At the immunohistochemical level, ND10 appear as nuclear punctate structures, with 10 indicating the approximate number of dots per nucleus observed. ND10 do not colocalize with kinetochores, centromeres, sites of mRNA processing, or chromosomes. Resistance of ND10 antigens to nuclease digestion and salt extraction suggest that ND10 are associated with the nuclear matrix. They are often identified by immunofluorescent assay using specific antibodies against PML, Death domain-associated protein, nuclear dot protein (NDP55), and so on. The role of ND10 has long been the subject of investigation, with the specific connection of ND10 and viral infection having been a particular focus for almost 20 years. This review summarizes the relationship of ND10 and viral infection. Some future study directions are also discussed.
Collapse
|
|
24
|
Distinct roles of Kaposi's sarcoma-associated herpesvirus-encoded viral interferon regulatory factors in inflammatory response and cancer. J Virol 2013; 87:9398-410. [PMID: 23785197 DOI: 10.1128/jvi.03315-12] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent associated with Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman disease (MCD). Similar to other herpesviruses, KSHV has two life cycles, latency and lytic replication. In latency, the KSHV genome persists as a circular episome in the nucleus of the host cell and only a few viral genes are expressed. In this review, we focus on oncogenic, antiapoptotic, and immunomodulating properties of KSHV-encoded homologues of cellular interferon regulatory factors (IRFs)--viral IRF1 (vIRF1) to vIRF4--and their possible role in the KSHV-mediated antiviral response, apoptosis, and oncogenicity.
Collapse
|
|
25
|
Everett RD, Boutell C, Hale BG. Interplay between viruses and host sumoylation pathways. Nat Rev Microbiol 2013; 11:400-11. [PMID: 23624814 DOI: 10.1038/nrmicro3015] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Post-translational modification by members of the small ubiquitin-like modifier (SUMO) family of proteins is important for the regulation of many cellular proteins and pathways. As obligate parasites, viruses must engage with the host cell throughout their replication cycles, and it is therefore unsurprising that there are many examples of interplay between viral proteins and the host sumoylation system. This article reviews recent advances in this field, summarizing information on sumoylated viral proteins, the varied ways in which viruses engage with SUMO-related pathways, and the consequences of these interactions for viral replication and engagement with innate and intrinsic immunity.
Collapse
Affiliation(s)
- Roger D Everett
- MRC-University of Glasgow Centre for Virus Research, 8 Church Street, Glasgow G11 5JR, UK.
| | | | | |
Collapse
|
|
26
|
Kaposi's sarcoma-associated herpesvirus lana2 protein interacts with the pocket proteins and inhibits their sumoylation. Oncogene 2013; 33:495-503. [PMID: 23318443 DOI: 10.1038/onc.2012.603] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 10/29/2012] [Accepted: 11/07/2012] [Indexed: 12/16/2022]
Abstract
The pocket proteins retinoblastoma protein (pRb), p107 and p130 are the key targets of oncoproteins expressed by DNA tumor viruses. Some of these viral proteins contain an LXCXE motif that mediates the interaction with the three pocket proteins and the inhibition of the pRb SUMOylation. Kaposi's sarcoma herpesvirus (KSHV) contains at least two proteins that can regulate pRb function but, so far, a KSHV-encoded protein targeting p107 and p130 has not been identified. Here, we show that the KSHV latent protein LANA2 binds to pRb, p107 and p130. LANA2 contains an LXCXE motif that is required for bypassing pRb-mediated cell-cycle arrest and for inhibiting pRb SUMOylation. Finally, we demonstrate that, in addition to pRb, both p107 and p130 can be SUMOylated, and this modification is also inhibited by LANA2 in an LXCXE-dependent manner. These results demonstrate, for the first time, the SUMOylation of p107 or p130 and, so far, they represent the first example of a KSHV protein able to interact with the three pocket proteins and to inhibit their conjugation to SUMO.
Collapse
|
|
27
|
Cheng X, Kao HY. Post-translational modifications of PML: consequences and implications. Front Oncol 2013; 2:210. [PMID: 23316480 PMCID: PMC3539660 DOI: 10.3389/fonc.2012.00210] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/16/2012] [Indexed: 12/23/2022] Open
Abstract
The tumor suppressor promyelocytic leukemia protein (PML) predominantly resides in a structurally distinct sub-nuclear domain called PML nuclear bodies. Emerging evidences indicated that PML actively participates in many aspects of cellular processes, but the molecular mechanisms underlying PML regulation in response to stress and environmental cues are not complete. Post-translational modifications, such as SUMOylation, phosphorylation, acetylation, and ubiquitination of PML add a complex layer of regulation to the physiological function of PML. In this review, we discuss the fast-moving horizon of post-translational modifications targeting PML.
Collapse
Affiliation(s)
- Xiwen Cheng
- Department of Biochemistry, School of Medicine, Case Western Reserve UniversityCleveland, OH, USA
- Comprehensive Cancer Center, Case Western Reserve UniversityCleveland, OH, USA
- University Hospital of Cleveland, Case Western Reserve UniversityCleveland, OH, USA
| | - Hung-Ying Kao
- Department of Biochemistry, School of Medicine, Case Western Reserve UniversityCleveland, OH, USA
- Comprehensive Cancer Center, Case Western Reserve UniversityCleveland, OH, USA
- University Hospital of Cleveland, Case Western Reserve UniversityCleveland, OH, USA
| |
Collapse
|
|
28
|
Sohn SY, Hearing P. Adenovirus regulates sumoylation of Mre11-Rad50-Nbs1 components through a paralog-specific mechanism. J Virol 2012; 86:9656-65. [PMID: 22740413 PMCID: PMC3446602 DOI: 10.1128/jvi.01273-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 06/19/2012] [Indexed: 01/09/2023] Open
Abstract
The Mre11-Rad50-Nbs1 (MRN) complex plays a key role in the DNA damage response, presenting challenges for DNA viruses and retroviruses. To inactivate this complex, adenovirus (Ad) makes use of the E1B-55K and E4-open reading frame 6 (ORF6) proteins for ubiquitin (Ub)-mediated, proteasome-dependent degradation of MRN and the E4-ORF3 protein for relocalization and sequestration of MRN within infected-cell nuclei. Here, we report that Mre11 is modified by the Ub-related modifier SUMO-2 and Nbs1 is modified by both SUMO-1 and SUMO-2. We found that Mre11 and Nbs1 are sumoylated during Ad5 infection and that the E4-ORF3 protein is necessary and sufficient to induce SUMO conjugation. Relocalization of Mre11 and Nbs1 into E4-ORF3 nuclear tracks is required for this modification to occur. E4-ORF3-mediated SUMO-1 conjugation to Nbs1 and SUMO-2 conjugation to Mre11 and Nbs1 are transient during wild-type Ad type 5 (Ad5) infection. In contrast, SUMO-1 conjugation to Nbs1 is stable in cells infected with E1B-55K or E4-ORF6 mutant viruses, suggesting that Ad regulates paralog-specific desumoylation of Nbs1. Inhibition of viral DNA replication blocks deconjugation of SUMO-2 from Mre11 and Nbs1, indicating that a late-phase process is involved in Mre11 and Nbs1 desumoylation. Our results provide direct evidence of Mre11 and Nbs1 sumoylation induced by the Ad5 E4-ORF3 protein and an important example showing that modification of a single substrate by both SUMO-1 and SUMO-2 is regulated through distinct mechanisms. Our findings suggest how E4-ORF3-mediated relocalization of the MRN complex influences the cellular DNA damage response.
Collapse
Affiliation(s)
- Sook-Young Sohn
- Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, New York, USA
| | | |
Collapse
|
|
29
|
Wilson VG. Sumoylation at the host-pathogen interface. Biomolecules 2012; 2:203-27. [PMID: 23795346 PMCID: PMC3685863 DOI: 10.3390/biom2020203] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 03/21/2012] [Accepted: 03/27/2012] [Indexed: 12/11/2022] Open
Abstract
Many viral proteins have been shown to be sumoylated with corresponding regulatory effects on their protein function, indicating that this host cell modification process is widely exploited by viral pathogens to control viral activity. In addition to using sumoylation to regulate their own proteins, several viral pathogens have been shown to modulate overall host sumoylation levels. Given the large number of cellular targets for SUMO addition and the breadth of critical cellular processes that are regulated via sumoylation, viral modulation of overall sumoylation presumably alters the cellular environment to ensure that it is favorable for viral reproduction and/or persistence. Like some viruses, certain bacterial plant pathogens also target the sumoylation system, usually decreasing sumoylation to disrupt host anti-pathogen responses. The recent demonstration that Listeria monocytogenes also disrupts host sumoylation, and that this is required for efficient infection, extends the plant pathogen observations to a human pathogen and suggests that pathogen modulation of host sumoylation may be more widespread than previously appreciated. This review will focus on recent aspects of how pathogens modulate the host sumoylation system and how this benefits the pathogen.
Collapse
Affiliation(s)
- Van G Wilson
- Department of Microbial & Molecular Pathogenesis, College of Medicine, Texas A&M Health Science Center, 8447 HWY 47, Bryan, TX 77807-1359
| |
Collapse
|
|
30
|
Abstract
The eukaryotic ubiquitin family encompasses nearly 20 proteins that are involved in the posttranslational modification of various macromolecules. The ubiquitin-like proteins (UBLs) that are part of this family adopt the β-grasp fold that is characteristic of its founding member ubiquitin (Ub). Although structurally related, UBLs regulate a strikingly diverse set of cellular processes, including nuclear transport, proteolysis, translation, autophagy, and antiviral pathways. New UBL substrates continue to be identified and further expand the functional diversity of UBL pathways in cellular homeostasis and physiology. Here, we review recent findings on such novel substrates, mechanisms, and functions of UBLs.
Collapse
|
|
31
|
SUMO binding by the Epstein-Barr virus protein kinase BGLF4 is crucial for BGLF4 function. J Virol 2012; 86:5412-21. [PMID: 22398289 DOI: 10.1128/jvi.00314-12] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
An Epstein-Barr virus (EBV) protein microarray was used to screen for proteins binding noncovalently to the small ubiquitin-like modifier SUMO2. Among the 11 SUMO binding proteins identified was the conserved protein kinase BGLF4. The mutation of potential SUMO interaction motifs (SIMs) in BGLF4 identified N- and C-terminal SIMs. The mutation of both SIMs changed the intracellular localization of BGLF4 from nuclear to cytoplasmic, while BGLF4 mutated in the N-terminal SIM remained predominantly nuclear. The mutation of the C-terminal SIM yielded an intermediate phenotype with nuclear and cytoplasmic staining. The transfer of BGLF4 amino acids 342 to 359 to a nuclear green fluorescent protein (GFP)-tagged reporter protein led to the relocalization of the reporter to the cytoplasm. Thus, the C-terminal SIM lies adjacent to a nuclear export signal, and coordinated SUMO binding by the N- and C-terminal SIMs blocks export and allows the nuclear accumulation of BGLF4. The mutation of either SIM prevented SUMO binding in vitro. The ability of BGLF4 to abolish the SUMOylation of the EBV lytic cycle transactivator ZTA was dependent on both BGLF4 SUMO binding and BGLF4 kinase activity. The global profile of SUMOylated cell proteins was also suppressed by BGLF4 but not by the SIM or kinase-dead BGLF4 mutant. The effective BGLF4-mediated dispersion of promyelocytic leukemia (PML) bodies was dependent on SUMO binding. The SUMO binding function of BGLF4 was also required to induce the cellular DNA damage response and to enhance the production of extracellular virus during EBV lytic replication. Thus, SUMO binding by BGLF4 modulates BGLF4 function and affects the efficiency of lytic EBV replication.
Collapse
|
|
32
|
Abstract
Since posttranslational modification (PTM) by the small ubiquitin-related modifiers (SUMOs) was discovered over a decade ago, a huge number of cellular proteins have been found to be reversibly modified, resulting in alteration of differential cellular pathways. Although the molecular consequences of SUMO attachment are difficult to predict, the underlying principle of SUMOylation is altering inter- and/or intramolecular interactions of the modified substrate, changing localization, stability, and/or activity. Unsurprisingly, many different pathogens have evolved to exploit the cellular SUMO modification system due to its functional flexibility and far-reaching functional downstream consequences. Although the extensive knowledge gained so far is impressive, a definitive conclusion about the role of SUMO modification during virus infection in general remains elusive and is still restricted to a few, yet promising concepts. Based on the available data, this review aims, first, to provide a detailed overview of the current state of knowledge and, second, to evaluate the currently known common principles/molecular mechanisms of how human pathogenic microbes, especially viruses and their regulatory proteins, exploit the host cell SUMO modification system.
Collapse
|