The growing interest in post-translational protein modification, particularly in SUMOylation, is driven by its crucial role in cell cycle regulation. SUMOylation affects various cell cycle regulators, including oncogenes, suggesting its relevance in cancer. SUMO E3 ligases are pivotal in this process, exhibiting diverse functionalities through structural domains and subcellular localizations. A less-explored SUMO E3 ligase, RANBP2, a component of the vertebrate nuclear pore complex, emerges as a central player in cellular cycle processes, as well as in tumorigenesis. The current studies illuminate the importance of RANBP2 and underscore the need for more extensive studies to validate its clinical applicability in neoplastic interventions. Our review elucidates the significance of RANBP2 across various types of malignancies. Additionally, it delves into exploring RANBP2 as a prospective therapeutic target for cancer treatment, offering insights into the avenues that scholars should pursue in their subsequent research endeavors. Thus, further investigation into RANBP2's role in solid tumorigenesis is eagerly awaited.

Backgroundp53 is a transcriptional factor that regulates numerous cellular processes, the stability and activity of p53 is essential to maintain its function. Post-translational modifications (PTMs), particularly SUMOylation, play a vital role in regulating p53 activity.ObjectiveTo investigate the neurogenesis related genes that downregulated by p53 SUMOylation in APP/PS1 mice, and the protected effect by overexpressing non-SUMOylated p53 (p53 K386R). Furthermore, to provide new clues for the mechanisms of Alzheimer's disease (AD).MethodsCo-immunoprecipitation was used to detect the p53 SUMOylation levels in neuro2a (N2a) cells and APP/PS1 mice overexpressing wild-type p53 (p53 WT) or p53 K386R. In addition, RNA sequencing (RNA-seq) was used to detect the p53 SUMOylation regulated genes. Then we used qPCR, western blot, and immunofluorescence to measure the expression of neuroglobin (ngb) and the effect of neurogenesis defects induced by p53 SUMOylation.ResultsWe verified that overexpression of p53 WT promoted p53 SUMOylation and p53 K386R decreased p53 SUMOylation in N2a cells and APP/PS1 mice. Ngb was related to neurogenesis which dramatically downregulated by p53 SUMOylation. In addition, we found p53 SUMOylation caused neuron reduction and impairment of neurogenesis.ConclusionsOur data support that p53 SUMOylation may lead to neurogenesis defects by downregulating ngb in AD, suggesting that inhibition of p53 SUMOylation may be served as a therapeutic strategy for preventing AD and provide a new target for future researches and interventions.

Coloration is an important appearance quality that contributes to product value. Anthocyanins, a type of flavonoid, not only impart rich plants color, but also contribute to human health because of their antioxidant properties, such as preventing cardiovascular disease and reducing obesity. This benefit mainly stems from various fruits. Accordingly, based on the consumption demand of beauty and nutrition, the creation of fruit tree products rich in anthocyanin is becoming an important breeding goal. The synthesis of anthocyanin has been investigated in various fruits, which is modulated by a variety of endogenous and exogenous factors, including transcription factors (TFs), plant hormones, and environmental factors (such as light, low temperature, drought). However, the detailed mechanisms in fruits of fruit trees have not been thoroughly elucidated. This review comprehensively examines the regulation of anthocyanin biosynthesis at the transcriptional, post-transcriptional, and post-translational levels, which is important for the application of molecular design strategies to cultivate high-quality fruits. At the transcriptional level, TFs were summarized to directly regulate anthocyanin biosynthesis genes, target non-anthocyanin biosynthesis pathway genes, interact with other proteins to mediate anthocyanin synthesis, and regulate anthocyanin synthesis by environmental factors and plant hormones. At the post-transcriptional level, non-coding RNAs (ncRNAs) were elucidated to mediate anthocyanin synthesis. At the post-translational level, a variety of post-translational modifications, including phosphorylation, ubiquitination, sumoylation, and persulfidation, have been elucidated to exhibit crucial functions in anthocyanin biosynthesis.

Horticultural crops are extensively cultivated throughout the world as crucial economical crops, encompassing fruits, vegetables, ornamentals, medicinal and beverage plants, for purposes such as food supply, special nutrition provision, medical application or aesthetic enjoyment. However, abiotic stress triggered by extreme climate change, such as excessive salt and prolonged drought, directly leads to the decline of nutritional quality of horticultural crops, contributing to the shortage of high-quality fruits. Post-translational modifications of proteins, such as phosphorylation and ubiquitination, can alter protein characteristics by adding specific groups to amino acids, which in turn impacts protein stability to regulate plant growth and development as well as environmental stress. Consequently, the revelation of the molecular mechanism of horticultural crops response to abiotic stress at post-translational modification level (PTMs) has always attracted a lot of scholars, as it is crucial for the development and breeding of climate-resilient apple varieties. At PTMs level, this review focuses on summarizing research advancements in horticultural crops responses to environmental stress, including drought, salt, cold, high temperature and iron (Fe) deficiency, with emphasis on sucrose non-fermentative 1 (SNF1) associated protein kinases (SnRKs) and mitogen-activated protein kinase (MAPK) cascade mediated phosphorylation, E3 ubiquitin ligases and BTB/TAZ subfamily BT2 mediated ubiquitination, SIZ1 SUMO E3 ligase mediated sumoylation, Nitric oxide (NO) mediated S-nitrosylation, and other forms of PTMs including protein glycosylation and lysine acetylation. In conclusion, this review adopts protein modification as an entry point to illuminate the mechanism of key genes regulating abiotic stress at PTMs level, providing a foundation for the cultivation of horticultural crops with superior resistance.

To identify efficient salt-tolerant genes is beneficial for coping with the penalty of salt stress on crop yield. Reversible conjugation (sumoylation and desumoylation) of Small Ubiquitin-Like Modifier (SUMO) is a crucial kind of protein modifications, but its roles in the response to salt and other abiotic stress are not well addressed. Here, we identify salt-tolerant SUMO protease gene TaDSU for desumoylation from wheat, and analyze its mechanism in salt tolerance and evaluate its role in yield in saline-alkaline fields. TaDSU overexpression enhances salt tolerance of wheat. TaDSU overexpressors have lower Na+ but higher K+ contents and consequently higher K+ : Na+ ratios than the wild-type under salt stress. TaDSU interacts with transcriptional factor MYC2, reduces the sumoylation level of SUMO1-conjugated MYC2, and promotes its transcription activity. MYC2 binds to the promoter of TaDSU and elevates its expression. TaDSU overexpression enhances grain yield of wheat in the saline soil without growth penalty in the normal field. Especially, TaDSU ectopic expression also enhances salt tolerance of Arabidopsis thaliana, showing this SUMO protease allele has the inter-species role in the adaptation to salt stress. Thus, TaDSU is an efficient candidate gene for molecular breeding of salt-tolerant crops.

Vascular endothelial cells are the predominant cell type in the cardiovascular system, and their dysfunction and death following hypoxic injury contribute to vascular lesions, playing an essential role in cardiovascular disease. Despite its importance, the mechanisms underlying vascular endothelial cell injury under hypoxia and potential therapeutic interventions remain poorly understood. Here, we constructed both an in vivo hypoxia model in C57BL/6 mice and an in vitro hypoxia model in HUVEC cells. Our findings demonstrated that hypoxia induces necroptosis in vascular endothelial cells and exacerbates inflammatory injury in vivo and in vitro, as evidenced by immunofluorescence and western blot. We identified FADD as a critical regulator of hypoxia-mediated necroptosis, with FADD knockdown significantly reversing hypoxia-induced necroptosis. Mechanistically, hypoxia affected protein conformation through SUMOylation of FADD and competitively inhibited its ubiquitination, leading to an increase in protein half-life and protein level of FADD. Furthermore, SUMOylation increased the interaction between FADD and RIPK1 and induced the formation of the FADD-RIPK1-RIPK3 complex, thereby promoting necroptosis in vascular endothelial cells. The SUMOylation inhibitor ginkgolic acid (GA) notably reduced hypoxia-induced vascular endothelial injury and inflammatory responses in male mice. Taken together, our research has uncovered a new process by which SUMOylation of FADD regulates hypoxia-induced necroptosis in endothelial cells, providing potential therapeutic targets for hypoxia-related cardiovascular diseases.

SUMOylation, the post-translational modification of proteins by small ubiquitin-like modifiers, plays a critical role in regulating various cellular processes, including innate immunity. This modification is essential for modulating immune responses and influencing signaling pathways that govern the activation and function of immune cells. Recent studies suggest that SUMOylation also contributes to the pathophysiology of central nervous system (CNS) viral infections, where it contributes to the host response and viral replication dynamics. Here, we explore the multifaceted role of SUMOylation in innate immune signaling and its implications for viral infections within the CNS. Notably, we present novel proteomic analyses aimed at elucidating the role of the small ubiquitin-related modifier (SUMO) in human immunodeficiency virus (HIV) latency in microglial cells. Our findings indicate that SUMOylation may regulate key proteins involved in maintaining viral latency, suggesting a potential mechanism by which HIV evades immune detection in the CNS. By integrating insights from proteomics with functional studies, we anticipate these findings to be the groundwork for future studies on HIV-host interactions and the mechanisms that underlie SUMOylation during latent and productive infection.

Ginkgolic acids (GAs) are distinctive secondary metabolites of Ginkgo biloba (G. biloba) primarily found in its leaves and seeds, with the highest concentration located in the exotesta. GAs are classified as long-chain phenolic compounds, and exhibit structural similarities to lignoceric acid. Their structural diversity arises from variations in the length of side chains and their number of double bonds, resulting in six distinct forms within G. biloba extracts (GBE). Of these, GA (C15:1) is the most prevalent. As inhibitors of SUMOylation, GAs demonstrate significant antitumor activity, and can exert antineoplastic effects through multiple pathways, which positions them as potentially promising therapeutic agents for cancer treatment. Additionally, GAs exhibit notable anti-inflammatory, antibacterial, and antiviral properties, highlighting their multifaceted medicinal potential. Although the pharmacological properties of GAs have been extensively investigated, the associated risks of liver and kidney damage must not be overlooked. GAs can induce significant hepatic damage by promoting cellular apoptosis, oxidative stress, and the disruption of various metabolic processes. Furthermore, a limited number of studies have indicated that GAs may exhibit nephrotoxicity, as well as adverse effects on the skin and nervous system. Due to their recognized toxicity, the concentration of GAs is typically regulated to within 5[Formula: see text]ppm in the standardized G. biloba leaf extract EGb 761. Currently, there is no definitive evidence supporting the mutagenic toxicity of GAs. This review primarily synthesizes recent advancements in understanding the pharmacological and toxicological effects of GAs, along with their underlying mechanisms. It is anticipated that this review will stimulate scholarly discourse and elicit valuable insights.

The Small Ubiquitin-like Modifier (SUMO) is a crucial post-translational modifier of proteins, playing a key role in various cellular functions. All SUMOs are synthesized as precursor proteins that must be proteolytically processed. However, the maturation process of cleaving the extending C-terminal tail, preceding SUMOylation of substrates, remains poorly understood, especially within cellular environments. Chemical protein synthesis coupled with cell delivery offers great opportunities to prepare SUMO analogues to investigate this process in vitro and in live cells. Applying this unique combination we show that SUMO2 analogues containing the native tail undergo rapid cleavage and nuclear localisation, while a Gly93Ala mutation impairs cleavage and alters localisation. Tail mutations (Val94Glu, Tyr95Ala) affected cleavage rates, highlighting roles in SUMO-SENP protease interactions. In cells, SUMO2 analogues containing tail mutations underwent cleavage and subsequently incorporated into promyelocytic leukemia nuclear bodies (PML-NBs). These findings advance our understanding of SUMO2 maturation and provide a foundation for future studies of this process for different SUMO paralogues in various cell lines and tissues.

Heat stress poses a significant threat to grain yield. As an α2 subunit of the 26S proteasome, TT1 has been shown to act as a critical regulator of rice heat tolerance. However, the heat tolerance mechanisms mediated by TT1 remain elusive. In this study, we unveiled that small ubiquitin-like modifier (SUMO)-conjugating enzyme 1 (SCE1), which interacts with TT1 and acts as a downstream component of TT1, is engaged in TT1-mediated 26S proteasome degradation. We showed that SCE1 functions as a negative regulator of heat tolerance in rice, which is associated with its ubiquitination modification. Furthermore, we observed that small heat-shock proteins (sHSPs) such as Hsp24.1 and Hsp40 can undergo SUMOylation mediated by SCE1, leading to increased accumulation of sHSPs in the absence of SCE1. Reducing protein levels of SCE1 significantly enhanced grain yield under high-temperature stress by improving seed-setting rate and rice grain filling capacity. Taken together, these results uncover the critical role of SCE1 in the TT1-mediated heat tolerance pathway by regulating the abundance of sHSPs and SUMOylation, and ultimately modulating rice heat tolerance. These findings underscore the great potential of the TT1-SCE1 module in improving the heat tolerance of crops.

Neurofibromin (Nf1) is a giant multidomain protein encoded by the tumour-suppressor gene NF1. NF1 is mutated in a common genetic disease, neurofibromatosis type I (NF1), and in various cancers. The protein has a Ras-GAP (GTPase activating protein) activity but is also connected to diverse signalling pathways through its SecPH domain, which interacts with lipids and different protein partners. We previously showed that Nf1 partially colocalized with the ProMyelocytic Leukemia (PML) protein in PML nuclear bodies, hotspots of SUMOylation, thereby suggesting the potential SUMOylation of Nf1. Here, we demonstrate that the full-length isoform 2 and a SecPH fragment of Nf1 are substrates of the SUMO pathway and identify a well-defined SUMOylation profile of SecPH with two main modified lysines. One of these sites, K1731, is highly conserved and surface-exposed. Despite the presence of an inverted SUMO consensus motif surrounding K1731, and a potential SUMO-interacting motif (SIM) within SecPH, we show that neither of these elements is necessary for K1731 SUMOylation, which is also independent of Ubc9 SUMOylation on K14. A 3D model of an interaction between SecPH and Ubc9 centred on K1731, combined with site-directed mutagenesis, identifies specific structural elements of SecPH required for K1731 SUMOylation, some of which are affected in reported NF1 pathogenic variants. This work provides a new example of SUMOylation dependent on the tertiary rather than primary protein structure surrounding the modified site, expanding our knowledge of mechanisms governing SUMOylation site selection.

A delicate balance between neural stem cell (NSC) quiescence and proliferation is important for adult neurogenesis and homeostasis. Small ubiquitin-related modifier (SUMO)-dependent post-translational modifications cause rapid and reversible changes in protein functions. However, the role of the SUMO pathway during NSC reactivation and brain development is not established. Here, we show that the key components of the SUMO pathway play an important role in NSC reactivation and brain development in Drosophila. Depletion of SUMO/Smt3 or SUMO conjugating enzyme Ubc9 results in notable defects in NSC reactivation and brain development, while their overexpression leads to premature NSC reactivation. Smt3 protein levels increase with NSC reactivation, which is promoted by the Ser/Thr kinase Akt. Warts/Lats, the core protein kinase of the Hippo pathway, can undergo SUMO- and Ubc9-dependent SUMOylation at Lys766. This modification attenuates Wts phosphorylation by Hippo, leading to the inhibition of the Hippo pathway, and consequently, initiation of NSC reactivation. Moreover, inhibiting Hippo pathway effectively restores the NSC reactivation defects induced by SUMO pathway inhibition. Overall, our study uncovered an important role for the SUMO-Hippo pathway during Drosophila NSC reactivation and brain development.

OsS1Fa1, a homologue of spinach S1Fa, is a small protein in rice that contains four distinct conserved motifs and participates in drought tolerance. However, the biological functions of these conserved motifs have not been characterized to date. Therefore, we investigated the roles of these conserved domains in the localization and cellular function of OsS1Fa1. We analysed the subcellular localization of OsS1Fa1 using confocal laser scanning microscopy (CLSM), following particle bombardment and bacterial infiltration. An E. coli in vivo reconstituted sumoylation assay was conducted to investigate sumoylation of OsS1Fa1. We characterized the function of the transmembrane domain of OsS1Fa1 in drought tolerance using transgenic Arabidopsis plants. Fluorescence analysis showed that OsS1Fa1 localized to the nuclear and cytoplasmic membranes. Mutation and cell fractionation analyses revealed that the membrane localization domain determined the subcellular localization of OsS1Fa1. The rice homologue OsS1Fa2 and Arabidopsis orthologs AtS1Fa1, AtS1Fa2, and AtS1Fa3 also exhibited similar localization patterns as OsS1Fa1. Sumoylation analysis demonstrated that OsS1Fa1 was conjugated with the small ubiquitin-related modifier (SUMO). Transgenic analysis showed that overexpression of OsS1Fa1(TMm1), a mutant form of the transmembrane domain of OsS1Fa1, in Arabidopsis did not enhance drought stress tolerance, whereas OsS1Fa1 overexpression improved the drought tolerance of transgenic Arabidopsis. Our data indicate that rice and Arabidopsis S1Fa1 proteins localize in the nuclear and cytoplasmic membranes, and that transmembrane domain determines subcellular localization and plays an important role in drought stress tolerance.

Responsible for COVID-19, SARS-CoV-2 is a coronavirus in which contagious variants continue to appear. Therefore, some population groups have demonstrated greater susceptibility to contagion and disease progression. For these reasons, several researchers have been studying the SARS-CoV-2/human interactome to understand the pathophysiology of COVID-19 and develop new pharmacological strategies. D. melanogaster is a versatile animal model with approximately 90 % human protein orthology related to SARS-CoV-2/human interactome and is widely used in metabolic studies. In this context, our work assessed the potential interaction between human proteins (ZNF10, NUP88, BCL2L1, UBC9, and RBX1) and their orthologous proteins in D. melanogaster (gl, Nup88, Buffy, ubc9, and Rbx1a) with proteins from SARS-CoV-2 (nsp3, nsp9, E, ORF7a, N, and ORF10) using computational approaches. Our results demonstrated that all the proteins have the potential to interact, and we compared the binding sites between humans and fruit flies. The stability and consistency in the structure of the gl_nsp3 complex, specifically, could be crucial for its specific biological functions. Lastly, to enhance the understanding of the influence of host factors on coronavirus infection, we also analyse the mRNA expression of the five genes (mbo, gl, lwr, Buffy, and Roc1a) responsible for encoding the fruit fly proteins. Briefly, we demonstrated that those genes were differentially regulated according to diets, sex, and age. Two groups showed higher positive gene regulation than others: females in the HSD group and males in the aging group, which could imply a higher virus-host susceptibility. Overall, while preliminary, our work contributes to the understanding of host defense mechanisms and potentially identifies candidate proteins and genes for in vivo viral studies against SARS-CoV-2.

Nucleotide excision repair (NER) is a major DNA repair system and hereditary defects in this system cause critical genetic diseases (e.g. xeroderma pigmentosum, Cockayne syndrome and trichothiodystrophy). Various proteins are involved in the eukaryotic NER system and undergo several post-translational modifications. Damaged DNA-binding protein 2 (DDB2) is a DNA damage recognition factor in the NER pathway. We previously demonstrated that DDB2 was SUMOylated in response to UV irradiation; however, its physiological roles remain unclear. We herein analysed several mutants and showed that the N-terminal tail of DDB2 was the target for SUMOylation; however, this region did not contain a consensus SUMOylation sequence. We found a SUMO-interacting motif (SIM) in the N-terminal tail that facilitated SUMOylation. The ubiquitination of a SUMOylation-deficient DDB2 SIM mutant was decreased, and its retention of chromatin was prolonged. The SIM mutant showed impaired NER, possibly due to a decline in the timely handover of the lesion site to XP complementation group C. These results suggest that the SUMOylation of DDB2 facilitates NER through enhancements in ubiquitination.

The signaling molecule auxin sits at the nexus of plant biology where it coordinates essentially all growth and developmental processes. Auxin molecules are transported throughout plant tissues and are capable of evoking highly specific physiological responses by inducing various molecular pathways. In many of these pathways, proteolysis plays a crucial role for correct physiological responses. This review provides a chronology of the discovery and characterization of the auxin receptor, which is a fascinating example of separate research trajectories ultimately converging on the discovery of a core auxin signaling hub that relies on degradation of a family of transcriptional inhibitor proteins-the Aux/IAAs. Beyond describing the "classical" proteolysis-driven auxin response system, we explore more recent examples of the interconnection of proteolytic systems, which target a range of other auxin signaling proteins, and auxin response. By highlighting these emerging concepts, we provide potential future directions to further investigate the role of protein degradation within the framework of auxin response.

T cell exhaustion refers to a progressive state in which T cells become functionally impaired due to sustained antigenic stimulation, which is characterized by increased expression of immune inhibitory receptors, but weakened effector functions, reduced self-renewal capacity, altered epigenetics, transcriptional programme and metabolism. T cell exhaustion is one of the major causes leading to immune escape of cancer, creating an environment that supports tumor development and metastatic spread. In addition, T cell exhaustion plays a pivotal role to the efficacy of current immunotherapies for cancer. This review aims to provide a comprehensive view of roles of T cell exhaustion in cancer development and progression. We summerized the regulatory mechanisms that involved in T cell exhaustion, including transcription factors, epigenetic and metabolic reprogramming events, and various microenvironmental factors such as cytokines, microorganisms, and tumor autocrine substances. The paper also discussed the challenges posed by T cell exhaustion to cancer immunotherapies, including immune checkpoint blockade (ICB) therapies and chimeric antigen receptor T cell (CAR-T) therapy, highlightsing the obstacles encountered in ICB therapies and CAR-T therapies due to T cell exhaustion. Finally, the article provides an overview of current therapeutic options aimed to reversing or alleviating T cell exhaustion in ICB and CAR-T therapies. These therapeutic approaches seek to overcome T cell exhaustion and enhance the effectiveness of immunotherapies in treating tumors.

SUMOylation is a dynamic and reversible post-translational modification (PTM) of proteins involved in the regulation of biological processes such as protein homeostasis, DNA repair and cell cycle in normal and tumor cells. In particular, overexpression of SUMOylation components in tumor cells increases the activity of intracellular SUMOylation, protects target proteins against ubiquitination degradation and activation, promoting tumor cell proliferation and metastasis, providing immune evasion and increasing tolerance to chemotherapy and antitumor drugs. However, with the continuous research on SUMOylation and with the continued development of SUMOylation inhibitors, it has been found that tumor initiation and progression can be inhibited by blocking SUMOylation and/or in combination with drugs. SUMOylation is not a bad target when trying to treat tumor. This review introduces SUMOylation cycle pathway and summarizes the role of SUMOylation in tumor initiation and progression and SUMOylation inhibitors and their functions in tumors and provides a prospective view of SUMOylation as a new therapeutic target for tumors.

SUMOylation, a post-translational modification involving the covalent attachment of small ubiquitin-like modifier (SUMO) proteins to target substrates, plays a pivotal role at the intersection of gut health and disease, influencing various aspects of intestinal physiology and pathology. This review provides a comprehensive examination of SUMOylation's diverse roles within the gut microenvironment. We examine its critical roles in maintaining epithelial barrier integrity, regulating immune responses, and mediating host-microbe interactions, thereby highlighting the complex molecular mechanisms that underpin gut homeostasis. Furthermore, we explore the impact of SUMOylation dysregulation in various intestinal disorders, including inflammatory bowel diseases and colorectal cancer, highlighting its implications as a potential diagnostic biomarker and therapeutic target. By integrating current research findings, this review offers valuable insights into the dynamic interplay between SUMOylation and gut health, paving the way for novel therapeutic strategies aimed at restoring intestinal equilibrium and combating associated pathologies.

cAMP response element-binding protein (CREB) is a ubiquitously expressed nuclear transcription factor, which can be constitutively activated regardless of external stimuli or be inducibly activated by external factors such as stressors, hormones, neurotransmitters, and growth factors. However, CREB controls diverse biological processes including cell growth, differentiation, proliferation, survival, apoptosis in a cell-type-specific manner. The diverse functions of CREB appear to be due to CREB-mediated differential gene expression that depends on cAMP response elements and multi-faceted regulation of CREB activity. Indeed, the transcriptional activity of CREB is controlled at several levels including alternative splicing, post-translational modification, dimerization, specific transcriptional co-activators, non-coding small RNAs, and epigenetic regulation. In this review, we present versatile regulatory modes of CREB family transcription factors and discuss their functional consequences.

Posttranslational modifications play a crucial role in governing cellular functions and protein behavior. Researchers have implicated dysregulated posttranslational modifications in protein misfolding, which results in cytotoxicity, particularly in neurodegenerative diseases such as Alzheimer disease, Parkinson disease, and Huntington disease. These aberrant posttranslational modifications cause proteins to gather in certain parts of the brain that are linked to the development of the diseases. This leads to neuronal dysfunction and the start of neurodegenerative disease symptoms. Cognitive decline and neurological impairments commonly manifest in neurodegenerative disease patients, underscoring the urgency of comprehending the posttranslational modifications' impact on protein function for targeted therapeutic interventions. This review elucidates the critical link between neurodegenerative diseases and specific posttranslational modifications, focusing on Tau, APP, α-synuclein, Huntingtin protein, Parkin, DJ-1, and Drp1. By delineating the prominent aberrant posttranslational modifications within Alzheimer disease, Parkinson disease, and Huntington disease, the review underscores the significance of understanding the interplay among these modifications. Emphasizing 10 key abnormal posttranslational modifications, this study aims to provide a comprehensive framework for investigating neurodegenerative diseases holistically. The insights presented herein shed light on potential therapeutic avenues aimed at modulating posttranslational modifications to mitigate protein aggregation and retard neurodegenerative disease progression.

SUMO (small ubiquitin like modifier) conjugated proteins have emerged as an important post translational modifier of cellular function. SUMOylation modulates several cellular processes involved in transcriptional regulation of genes, protein-protein interactions and DNA damage and repair. Since abnormalities in SUMOylation has been observed in neoplastic and neurodegenerative disorders, the SUMO pathway has become an attractive site for targeting of new therapies to regulate SUMOylation and reduce disease burden. Conjugation of SUMO to their respective substrates is orchestrated by an enzymatic cascade involving three main enzymes, E1, activation enzyme, E2, conjugating enzyme and E3, a protein ligase. Each of these enzymes are therefore potential "druggable" sites for future therapeutics. SUMOylation is a well-known mechanism by which the innate immune response is regulated in response to viral infections and in the adaptive immune response to tumor immunity. We have shown that small molecules which inhibit the SUMO activation pathway are also capable of inhibiting autoimmune response. TAK981 which forms adducts with SUMO and anacardic acid which inhibits the E1 enzyme of the SUMO pathway were effective in preventing the development of experimental allergic encephalitis (EAE), a mouse model of multiple sclerosis. Anacardic acid and TAK981 inhibited activation of TH17 cells and reduced clinical and pathological injury in IL-17 mediated myelin oligodendrocyte glycoprotein (MOG) induced EAE. Ginkgolic acid, another known inhibitor of SUMO pathway, was also shown to be effective in reducing the severity of inflammatory arthropathies which is also IL-17 mediated. In addition, the increase in the transcription of myelin genes with TAK981 and anacardic acid improved remyelination in experimental models of demyelination. In the present review paper, we examine the mechanism of action of inhibitors of the SUMO pathway on regulating the immune response and the possibility of the use of these agents as therapeutics for MS.

Homeostasis of the endoplasmic reticulum (ER) is critical for growth, development, and stress responses. Perturbations causing an imbalance in ER proteostasis lead to a potentially lethal condition known as ER stress. In ER stress situations, cell-fate decisions either activate pro-life pathways that reestablish homeostasis or initiate pro-death pathways to prevent further damage to the organism. Understanding the mechanisms underpinning cell-fate decisions in ER stress is critical for crop development and has the potential to enable translation of conserved components to ER stress-related diseases in metazoans. Post-translational modifications (PTMs) of proteins are emerging as key players in cell-fate decisions in situations of imbalanced ER proteostasis. In this review, we address PTMs orchestrating cell-fate decisions in ER stress in plants and provide evidence-based perspectives for where future studies may focus to identify additional PTMs involved in ER stress management.

Enhancers are fundamental to gene regulation. Post-translational modifications by the small ubiquitin-like modifiers (SUMO) modify chromatin regulation enzymes, including histone acetylases and deacetylases. However, it remains unclear whether SUMOylation regulates enhancer marks, acetylation at the 27th lysine residue of the histone H3 protein (H3K27Ac). To investigate whether SUMOylation regulates H3K27Ac, we performed genome-wide ChIP-seq analyses and discovered that knockdown (KD) of the SUMO activating enzyme catalytic subunit UBA2 reduced H3K27Ac at most enhancers. Bioinformatic analysis revealed that TFAP2C-binding sites are enriched in enhancers whose H3K27Ac was reduced by UBA2 KD. ChIP-seq analysis in combination with molecular biological methods showed that TFAP2C binding to enhancers increased upon UBA2 KD or inhibition of SUMOylation by a small molecule SUMOylation inhibitor. However, this is not due to the SUMOylation of TFAP2C itself. Proteomics analysis of TFAP2C interactome on the chromatin identified histone deacetylation (HDAC) and RNA splicing machineries that contain many SUMOylation targets. TFAP2C KD reduced HDAC1 binding to chromatin and increased H3K27Ac marks at enhancer regions, suggesting that TFAP2C is important in recruiting HDAC machinery. Taken together, our findings provide insights into the regulation of enhancer marks by SUMOylation and TFAP2C and suggest that SUMOylation of proteins in the HDAC machinery regulates their recruitments to enhancers.

EH domain-containing protein 2 (EHD2) is a member of the EHD protein family and is mainly located in the plasma membrane, but can also be found in the cytoplasm and endosomes. EHD2 is also a nuclear-cytoplasmic shuttle protein. After entering the cell nuclear, EHD2 acts as a corepressor of transcription to inhibit gene transcription. EHD2 regulates a series of biological processes. As a key regulator of endocytic transport, EHD2 is involved in the formation and maintenance of endosomal tubules and vesicles, which are critical for the intracellular transport of proteins and other substances. The N-terminal of EHD2 is attached to the cell membrane, while its C-terminal binds to the actin-binding protein. After binding, EHD2 connects with the actin cytoskeleton, forming the curvature of the membrane and promoting cell endocytosis. EHD2 is also associated with membrane protein trafficking and receptor signaling, as well as in glucose metabolism and lipid metabolism. In this review, we highlight the recent advances in the function of EHD2 in various cellular processes and its potential implications in human diseases such as cancer and metabolic disease. We also discussed the prospects for the future of EHD2. EHD2 has a broad prospect as a therapeutic target for a variety of diseases. Further research is needed to explore its mechanism, which could pave the way for the development of targeted treatments.

Plants regularly encounter various environmental stresses such as salt, drought, cold, heat, heavy metals and pathogens, leading to changes in their proteome. Of these, a post-translational modification, SUMOylation is particularly significant for its extensive involvement in regulating various plant molecular processes to counteract these external stressors. Small ubiquitin-like modifiers (SUMO) protein modification significantly contributes to various plant functions, encompassing growth, development and response to environmental stresses. The SUMO system has a limited number of ligases even in fully sequenced plant genomes but SUMO E3 ligases are pivotal in recognising substrates during the process of SUMOylation. E3 ligases play pivotal roles in numerous biological and developmental processes in plants, including DNA repair, photomorphogenesis, phytohormone signalling and responses to abiotic and biotic stress. A considerable number of targets for E3 ligases are proteins implicated in reactions to abiotic and biotic stressors. This review sheds light on how plants respond to environmental stresses by focusing on recent findings on the role of SUMO E3 ligases, contributing to a better understanding of how plants react at a molecular level to such stressors.

As an excellent fusion tag for expressing heterologous proteins, yeast SUMO (small ubiquitin-related modifier) has unique advantages such as improving solubility, promoting stability, and reducing degradation, but it lacks a simple and rapid purification method. Camelid single-domain antibodies (VHHs or nanobodies) show great promise as an efficient tool in analytical application. In this study, VHHs against SUMO protein were isolated for the first time using biopanning of an immune camelid nanobody library. Among these nanobodies, VS2 demonstrated a high expression level (1.12 g L - 1), and a high affinity for SUMO (2.26 nM). Meanwhile, VHHs were coupled to agarose resins by cysteine at the C-terminal to form affinity chromatography resins. The VS2 resin showed excellent specificity and a dynamic binding capacity for SUMO, SUMO-DsbA (disulfide oxidoreductase) and SUMO-SAM (S-adenosylmethionine synthetase) were 2.41 mg/mL resin, 7.57 mg/mL resin and 16.23 mg/mL resin, respectively. Furthermore, the VS2 resin enabled one-step purification of SUMO-fusions [SUMO-Fc (human IgG1-Fc fragment), SUMO-IGF1 (human insulin-like growth factor 1), SUMO-FGF21 (human fibroblast growth factor 21), SUMO-G-CSF (human Granulocyte colony-stimulating factor), SUMO-PDGF (human platelet-derived growth factor) and SUMO-PAS200 (conformationally disordered polypeptide chains with expanded hydrodynamic volume comprising the small residues Pro, Ala-and Ser)], and maintained binding capacity and selectivity over 25 purification cycles, each including 15 min of cleaning-in-place with 0.1 M NaOH. This study demonstrated that the VS2 resin was a useful tool at the laboratory scale for one-step purification of various SUMO fusions from complex mixtures.

As an important posttranslational modification, SUMOylation plays critical roles in almost all biological processes. Although it has been well-documented that SUMOylated proteins are mainly localized in the nucleus and have roles in chromatin-related processes, we showed recently that the SUMOylation machinery is actually enriched in the nuclear matrix rather than chromatin. Here, we provide compelling biochemical, cellular imaging and proteomic evidence that SUMOylated proteins are highly enriched in the nuclear matrix. We demonstrated that inactivation of SUMOylation by inhibiting SUMO-activating E1 enzyme or KO of SUMO-conjugating E2 enzyme UBC9 have only mild effect on nuclear matrix composition, indicating that SUMOylation is neither required for nuclear matrix formation nor for targeting proteins to nuclear matrix. Further characterization of UBC9 KO cells revealed that loss of SUMOylation did not result in significant DNA damage, but led to mitotic arrest and chromosome missegregation. Altogether, our study demonstrates that SUMOylated proteins are selectively enriched in the nuclear matrix and suggests a role of nuclear matrix in mediating SUMOylation and its regulated biological processes.

The regulation of mRNA transcription and translation is uncoupled during oogenesis. The reason for this uncoupling is two-fold. Chromatin is only accessible to the transcriptional machinery during the growth phase as it condenses prior to resumption of meiosis to ensure faithful segregation of chromosomes during meiotic maturation. Thus, transcription rates are high during this time period in order to produce all of the transcripts needed for meiosis, fertilization, and embryo cleavage until the newly formed embryonic genome becomes transcriptionally active. To ensure appropriate timing of key developmental milestones including chromatin condensation, resumption of meiosis, segregation of chromosomes, and polar body extrusion, the translation of protein from transcripts synthesized during oocyte growth must be temporally regulated. This is achieved by the regulation of mRNA interaction with RNA binding proteins and shortening and lengthening of the poly(A) tail. This chapter details the essential factors that regulate the dynamic changes in mRNA synthesis, storage, translation, and degradation during oocyte growth and maturation.

Type I interferon (IFN-I)-induced signaling plays a critical role in host antiviral innate immune responses. Despite this, the mechanisms that regulate this signaling pathway have yet to be fully elucidated. The nucleoporin Ran Binding Protein 2 (RanBP2) (also known as Nucleoporin 358 KDa, Nup358) has been implicated in a number of cellular processes, including host innate immune signaling pathways, and is known to influence viral infection. In this study, we documented that RanBP2 mediates the sumoylation of signal transducers and activators of transcription 1 (STAT1) and inhibits IFN-α-induced signaling. Specifically, we found that RanBP2-mediated sumoylation inhibits the interaction of STAT1 and Janus kinase 1 (JAK1), as well as the phosphorylation and nuclear accumulation of STAT1 after IFN-α stimulation, thereby antagonizing the IFN-α-mediated antiviral innate immune signaling pathway and promoting viral infection. Our findings not only provide insights into a novel function of RanBP2 in antiviral innate immunity but may also contribute to the development of new antiviral therapeutic strategies.

CRISPR screens have empowered the high-throughput dissection of gene functions; however, more explicit genetic elements, such as codons of amino acids, require thorough interrogation. Here, we establish a CRISPR strategy for unbiasedly probing functional amino acid residues at the genome scale. By coupling adenine base editors and barcoded sgRNAs, we target 215,689 out of 611,267 (35%) lysine codons, involving 85% of the total protein-coding genes. We identify 1,572 lysine codons whose mutations perturb human cell fitness, with many of them implicated in cancer. These codons are then mirrored to gene knockout screen data to provide functional insights into the role of lysine residues in cellular fitness. Mining these data, we uncover a CUL3-centric regulatory network in which lysine residues of CUL3 CRL complex proteins control cell fitness by specifying protein-protein interactions. Our study offers a general strategy for interrogating genetic elements and provides functional insights into the human proteome.

Glutamine synthetase (GS) is a crucial enzyme involved in de novo synthesis of glutamine and participates in several biological processes, including nitrogen metabolism, nucleotide synthesis, and amino acid synthesis. Post-translational modification makes GS more adaptable to the needs of cells, and acetylation modification of GS at double sites has attracted considerable attention. Despite very intensive research, how SUMOylation affects GS activity at a molecular level remains unclear. Here, we report that previously undiscovered GS SUMOylation which is deficient mutant K372R of GS exhibits more bluntness under glutamine starvation. Mechanistically, glutamine deprivation triggers the GS SUMOylation, and this SUMOylation impaired the protein stability of GS, within a concomitant decrease in enzymatic activity. In addition, we identified SAE1, Ubc9, and PIAS1 as the assembly enzymes of GS SUMOylation respectively. Furthermore, Senp1/2 functions as a SUMO-specific protease to reverse the SUMOylation of GS. This study provides the first evidence that SUMOylation serves as a regulatory mechanism for determining the GS enzymatic activity, contributing to understanding the GS regulation roles in various cellular and pathophysiological processes.

Various post-translational modifications (PTMs) collaboratively fine-tune protein activities. SUMO-targeted ubiquitin E3 ligases (STUbLs) emerge as specialized enzymes that recognize SUMO-modified substrates through SUMO-interaction motifs and subsequently ubiquitinate them via the RING domain, thereby bridging the SUMO and ubiquitin signaling pathways. STUbLs participate in a wide array of molecular processes, including cell cycle regulation, DNA repair, replication, and mitosis, operating under both normal conditions and in response to challenges such as genotoxic stress. Their ability to catalyze various types of ubiquitin chains results in diverse proteolytic and non-proteolytic outcomes for target substrates. Importantly, STUbLs are strategically positioned in close proximity to SUMO proteases and deubiquitinases (DUBs), ensuring precise and dynamic control over their target proteins. In this review, we provide insights into the unique properties and indispensable roles of STUbLs, with a particular emphasis on their significance in preserving genome integrity in humans.

Post-translational modifications (PTMs) have key roles in extending the functional diversity of proteins and, as a result, regulating diverse cellular processes in prokaryotic and eukaryotic organisms. Phosphorylation modification is a vital PTM that occurs in most proteins and plays a significant role in many biological processes. Disorders in the phosphorylation process lead to multiple diseases, including neurological disorders and cancers. The purpose of this review is to organize this body of knowledge associated with phosphorylation site (p-site) prediction to facilitate future research in this field. At first, we comprehensively review all related databases and introduce all steps regarding dataset creation, data preprocessing, and method evaluation in p-site prediction. Next, we investigate p-site prediction methods, which are divided into two computational groups: algorithmic and machine learning (ML). Additionally, it is shown that there are basically two main approaches for p-site prediction by ML: conventional and end-to-end deep learning methods, both of which are given an overview. Moreover, this review introduces the most important feature extraction techniques, which have mostly been used in p-site prediction. Finally, we create three test sets from new proteins related to the released version of the database of protein post-translational modifications (dbPTM) in 2022 based on general and human species. Evaluating online p-site prediction tools on newly added proteins introduced in the dbPTM 2022 release, distinct from those in the dbPTM 2019 release, reveals their limitations. In other words, the actual performance of these online p-site prediction tools on unseen proteins is notably lower than the results reported in their respective research papers.

Small ubiquitin like modifiers (SUMO) are reversible posttranslational modifiers of intracellular proteins. In the CNS, expression of myelin genes is regulated by state of SUMOylation of their respective transcription factors. In the immune system, deSUMOylation activates innate immune responses and promotes anti-viral immunity. However, the role played by SUMO in an adaptive immune response and in the development of T cell mediated autoimmune disease has not been previously described. TAK981 is a synthetic small molecule which by forming adducts with SUMO proteins prevents SUMOylation. We examined the expression of myelin genes and their transcription factors following culture with TAK981 in Oligodendrocyte Precursor Cells (OPC). We found that myelin basic protein (MBP), a key myelin protein, is upregulated in OPC in the presence of TAK981. We also found increased expression of transcription factors Sox10 and Myrf, which engage in the expression of MBP. In the Cuprizone model of demyelination/remyelination, animals which were treated with TAK981 showed increased remyelination in areas of demyelination and an increase in the number of maturing oligodendrocytes compared to vehicle treated controls. In in vitro cultures of lymphocytes, TAK981 reduced the expression of TH17 in T cells in mice immunized with MOGp35-55. Following in vivo treatment with TAK981, there was a significant reduction in the clinical and pathological severity in mice immunized to develop experimental allergic encephalitis (EAE). The dual effects of deSUMOylation on remyelination and in regulating an autoimmune adaptive response offers a novel approach to the management of human inflammatory demyelinating diseases such as multiple sclerosis.

The SUMO family is a type of ubiquitin-like protein modification molecule. Its protein modification mechanism is similar to that of ubiquitination: both involve modifier-activating enzyme E1, conjugating enzyme E2 and substrate-specific ligase E3. However, polyubiquitination can lead to the degradation of substrate proteins, while poly-SUMOylation only leads to the degradation of substrate proteins through the proteasome pathway after being recognized by ubiquitin as a signal factor. There are currently five reported subtypes in the SUMO family, namely SUMO1-5. As a reversible dynamic modification, intracellular sentrin/SUMO-specific proteases (SENPs) mainly regulate the reverse reaction pathway of SUMOylation. The SUMOylation modification system affects the localization, activation and turnover of proteins in cells and participates in regulating most nuclear and extranuclear molecular reactions. Abnormal expression of proteins related to the SUMOylation pathway is commonly observed in tumors, indicating that this pathway is closely related to tumor occurrence, metastasis and invasion. This review mainly discusses the composition of members in the protein family related to SUMOylation pathways, mutual connections between SUMOylation and other post-translational modifications on proteins as well as therapeutic drugs developed based on these pathways.

Saccharomyces cerevisiae Pso2/SNM1 is essential for DNA interstrand crosslink (ICL) repair; however, its mechanism of action remains incompletely understood. While recent work has revealed that Pso2/Snm1 is dual-localized in the nucleus and mitochondria, it remains unclear whether cell-intrinsic and -extrinsic factors regulate its subcellular localization and function. Herein, we show that Pso2 undergoes ubiquitination and phosphorylation, but not SUMOylation, in unstressed cells. Unexpectedly, we found that methyl methanesulfonate (MMS), rather than ICL-forming agents, induced robust SUMOylation of Pso2 on two conserved residues, K97 and K575, and that SUMOylation markedly increased its abundance in the mitochondria. Reciprocally, SUMOylation had no discernible impact on Pso2 translocation to the nucleus, despite the presence of steady-state levels of SUMOylated Pso2 across the cell cycle. Furthermore, substitution of the invariant residues K97 and K575 by arginine in the Pso2 SUMO consensus motifs severely impaired SUMOylation and abolished its translocation to the mitochondria of MMS-treated wild type cells, but not in unstressed cells. We demonstrate that whilst Siz1 and Siz2 SUMO E3 ligases catalyze Pso2 SUMOylation, the former plays a dominant role. Notably, we found that the phenotypic characteristics of the SUMOylation-defective mutant Pso2K97R/K575R closely mirrored those observed in the Pso2Δ petite mutant. Additionally, leveraging next-generation sequencing analysis, we demonstrate that Pso2 mitigates MMS-induced damage to mitochondrial DNA (mtDNA). Viewed together, our work offers previously unknown insights into the link between genotoxic stress-induced SUMOylation of Pso2 and its preferential targeting to the mitochondria, as well as its role in attenuating MMS-induced mtDNA damage.

Small ubiquitin-like modifier (SUMO) typically conjugates to target proteins through isopeptide linkage to the ε-amino group of lysine residues. This posttranslational modification (PTM) plays pivotal roles in modulating protein function. Cofilins are key regulators of actin cytoskeleton dynamics and are well-known to undergo several different PTMs. Here, we show that cofilin-1 is conjugated by SUMO1 both in vitro and in vivo. Using mass spectrometry and biochemical and genetic approaches, we identify the N-terminal α-amino group as the SUMO-conjugation site of cofilin-1. Common to conventional SUMOylation is that the N-α-SUMOylation of cofilin-1 is also mediated by SUMO activating (E1), conjugating (E2), and ligating (E3) enzymes and reversed by the SUMO deconjugating enzyme, SENP1. Specific to the N-α-SUMOylation is the physical association of the E1 enzyme to the substrate, cofilin-1. Using F-actin co-sedimentation and actin depolymerization assays in vitro and fluorescence staining of actin filaments in cells, we show that the N-α-SUMOylation promotes cofilin-1 binding to F-actin and cofilin-induced actin depolymerization. This covalent conjugation by SUMO at the N-α amino group of cofilin-1, rather than at an internal lysine(s), serves as an essential PTM to tune cofilin-1 function during regulation of actin dynamics.

The establishment of the rhizobium-legume symbiosis is generally based on plant perception of Nod factors (NFs) synthesized by the bacteria. However, some Bradyrhizobium strains can nodulate certain legume species, such as Aeschynomene spp. or Glycine max, independently of NFs, and via two different processes that are distinguished by the necessity or not of a type III secretion system (T3SS). ErnA is the first known type III effector (T3E) triggering nodulation in Aeschynomene indica. In this study, a collection of 196 sequenced Bradyrhizobium strains was tested on A. indica. Only strains belonging to the photosynthetic supergroup can develop a NF-T3SS-independent symbiosis, while the ability to use a T3SS-dependent process is found in multiple supergroups. Of these, 14 strains lacking ernA were tested by mutagenesis to identify new T3Es triggering nodulation. We discovered a novel T3E, Sup3, a putative SUMO-protease without similarity to ErnA. Its mutation in Bradyrhizobium strains NAS96.2 and WSM1744 abolishes nodulation and its introduction in an ernA mutant of strain ORS3257 restores nodulation. Moreover, ectopic expression of sup3 in A. indica roots led to the formation of spontaneous nodules. We also report three other new T3Es, Ubi1, Ubi2 and Ubi3, which each contribute to the nodulation capacity of strain LMTR13. These T3Es have no homology to known proteins but share with ErnA three motifs necessary for ErnA activity. Together, our results highlight an unsuspected distribution and diversity of T3Es within the Bradyrhizobium genus that may contribute to their symbiotic efficiency by participating in triggering legume nodulation.

The recent discovery of TAK981(Subasumstat), the first-in-class selective inhibitor of SUMOylation, enables new immune treatments. TAK981 is already in clinical trials to potentiate immunotherapy in metastatic tumors and hematologic malignancies. Cancer patients have more than ten times higher risk of infections, but the effects of TAK981 in sepsis are unknown and previous studies on SUMO in infections are conflicting.

We used TAK981 in two sepsis models; polymicrobial peritonitis (CLP) and LPS endotoxemia. Splenectomy was done in both models to study the role of spleen. Western blotting of SUMO-conjugated proteins in spleen lysates was done. Global SUMO1 and SUMO3 knockout mice were used to study the specific SUMO regulation of inflammation in LPS endotoxemia. Splenocytes adoptive transfer was done from SUMO knockouts to wild type mice to study the role of spleen SUMOylation in experimental sepsis.

Here, we report that inhibition of SUMOylation with TAK981 improved survival in mild polymicrobial peritonitis by enhancing innate immune responses and peritoneal bacterial clearance. Thus, we focused on the effects of TAK981 on the immune responses to bacterial endotoxin, showing that TAK981 enhanced early TNFα production but did not affect the resolution of inflammation. Splenectomy decreased serum TNFα levels by nearly 60% and TAK981-induced TNFα responses. In the spleen, endotoxemia induced a distinct temporal and substrate specificity for SUMO1 and SUMO2/3, and both were inhibited by TAK981. Global genetic depletion of SUMO1, but not SUMO3, enhanced TNFα production and metabolic acidosis. The transfer of SUMO1-null, but not wild-type, splenocytes into splenectomized wild-type mice exacerbated TNFα production and metabolic acidosis in endotoxemia.

These results suggest that specific regulation of splenic SUMO1 can modulate immune and metabolic responses to bacterial infection.