Histone H2A monoubiquitination is associated with transcriptional repression and needs to be removed by deubiquitinases to facilitate gene transcription in eukaryotes.However,the deubiquitinase responsible for genome-...Histone H2A monoubiquitination is associated with transcriptional repression and needs to be removed by deubiquitinases to facilitate gene transcription in eukaryotes.However,the deubiquitinase responsible for genome-wide H2A deubiquitination in plants has yet to be identified.In this study,we found that the previously identified PWWP-EPCR-ARID-TRB(PEAT)complex components interact with both the ubiquitin-specific protease UBP5 and the redundant histone acetyltransferases HAM1 and HAM2(HAM1/2)to form a larger version of PEAT complex in Arabidopsis thaliana.UBP5 functions as an H2A deubiquitinase in a nucleosome substrate-dependent manner in vitro and mediates H2A deubiquitination at the whole-genome level in vivo.HAM1/2 are shared subunits of the PEAT complex and the conserved NuA4 histone acetyltransferase com-plex,and are responsible for histone H4K5 acetylation.Within the PEAT complex,the PWWP components(PWWP1,PWWP2,and PWWP3)directly interact with UBP5 and are necessary for UBP5-mediated H2A deu-biquitination,while the EPCR components(EPCR1 and EPCR2)directly interact with HAM1/2 and are required for HAM1/2-mediated H4K5acetylation.Collectively,our study not onlyidentifies dual roles of thePEAT com-plex in H2A deubiquitination and H4K5 acetylation but also illustrates how these processes collaborate at the whole-genome level to regulate the transcription and development in plants.展开更多
Deubiquitinating enzymes(DUBs) or deubiquitinases facilitate the escape of multiple proteins from ubiquitin-proteasome degradation and are critical for regulating protein expression levels in vivo.Therefore,dissecting...Deubiquitinating enzymes(DUBs) or deubiquitinases facilitate the escape of multiple proteins from ubiquitin-proteasome degradation and are critical for regulating protein expression levels in vivo.Therefore,dissecting the underlying mechanism of DUB recognition is needed to advance the development of drugs related to DUB signaling pathways.To data,extensive studies on the ubiquitin chain specificity of DUBs have been reported,but substrate protein recognition is still not clearly understood.As a breakthrough,the scaffolding role may be significant to substrate protein selectivity.From this perspective,we systematically characterized the scaffolding proteins and complexes contributing to DUB substrate selectivity.Furthermore,we proposed a deubiquitination complex platform(DCP) as a potentially generic mechanism for DUB substrate recognition based on known examples,which might fill the gaps in the understanding of DUB substrate specificity.展开更多
As members of the immune checkpoint family, PD-1 and its ligand PD-L1 play critical roles in maintaining the balance between autoimmunity and tolerance. The interaction of PD-1/PD-L1 is also involved in tumor evasion ...As members of the immune checkpoint family, PD-1 and its ligand PD-L1 play critical roles in maintaining the balance between autoimmunity and tolerance. The interaction of PD-1/PD-L1 is also involved in tumor evasion inside the tumor microenvironment, caused by reduced T cell activation, proliferation, cytotoxic secretion, and survival. Previous research has shown that the expression level of PD-1/PD-L1 may be regulated by ubiquitin-mediated proteasome degradation, which is an important mode of post-translational modification (PTM). PD-1/PD-L1 ubiquitin modification research in tumor immunotherapy is the subject of the present review, which aims to assess the most recent developments in this area. We offer a short explanation of PD-1/PD-L1 as well as some basic background information on the UPS system and discuss many routes that target E3s and DUBs, respectively, in the regulation of PD-1/PD-L1 in tumor immunotherapy. In addition, we offer numerous innovative prospective research areas for the future, as well as novel immunotherapy concepts and ideas. Taken together, the information compiled herein should serve as a comprehensive repository of information about tumor immunotherapy that is currently available, and it should be useful in the design of future studies, as well as the development of potential targets and strategies for future tumor immunotherapy.展开更多
Objective:To investigate the effects and underlying mechanism of 2-hexyl-4-pentynoic acid(HPTA),a derivative of valproic acid(VPA),on radiotherapy in breast cancer.Methods:MCF7 cells and 7,12-dimethylbenz-[α]-anthrac...Objective:To investigate the effects and underlying mechanism of 2-hexyl-4-pentynoic acid(HPTA),a derivative of valproic acid(VPA),on radiotherapy in breast cancer.Methods:MCF7 cells and 7,12-dimethylbenz-[α]-anthracene(DMBA)-induced transformed human normal breast cells(MCF10A–DMBA cells)were irradiated with 8 Gy X-rays.For both cells there were four groups:control,valproic acid(VPA)/HPTA,IR,and VPA/HPTA+IR groups.MTT and clonogenic survival assays were performed to assess cell proliferation,and comet assay was performed to evaluate DNA damage.Protein expression ofγH2AX,53BP1,Rad51,and BRCA1 was examined via immunofluorescence and immunoblotting.Cycloheximide chase and ubiquitination experiments were conducted to determine Rad51 ubiquitination.In vivo experiments involved a rat model of DMBA-induced breast cancer,with four fractionated doses of 2 Gy.Tumor tissue pathological changes andγH2AX,Rad51,and UCHL3 expression levels were measured by hematoxylin-eosin staining,immunohistochemistry,and immunoblotting.Results:Compared with the IR group,15μmol/L HPTA reduced the cell proliferation ability of irradiated MCF7 cells(t=2.16,P<0.05).The VPA/HPTA+IR group exhibited significantly increased DNA double-strand breaks relative to those in the IR group(VPA+IR vs.IR,t=13.37,P<0.05;HPTA+IR vs.IR,t=8.48,P<0.05).Immunofluorescence and immunoblotting experiments demonstrated that the VPA/HPTA+IR group displayed signifi-cantly increased cell foci formation,γH2AX and 53BP1 protein expression levels compared to the IR group[(γH2AX:VPA+IR vs.IR,t=8.88,P<0.05;HPTA+IR vs.IR,t=8.90,P<0.05),(53BP1,VPA+IR vs.IR,t=5.73,P<0.05;HPTA+IR vs.IR,t=6.40,P<0.05)].Further,Rad51 expression was downregulated(VPA+IR vs.IR,t=3.12,P<0.05;HPTA+IR vs.IR,t=2.70,P<0.05),and Rad51 inhibition effectively counteracted HPTA-induced radiosensitization.Ubiquitination detection further verified that HPTA inhibits Rad51 expression via UCHL3-dependent Rad51 deubiquitination.In vivo study results showed that 20 mg/kg HPTA significantly enhanced the radiosensitivity of breast tumors in rats by inhibiting Rad51 expression.Conclusions:HPTA is a highly effective radiosensitizer that enhances the radiotherapeutic efficacy of breast cancer treatment through UCHL3-dependent deubiquitination of Rad51.展开更多
Objective Obesity-induced kidney injury contributes to the development of diabetic nephropathy(DN).Here,we identified the functions of ubiquitin-specific peptidase 19(USP19)in HK-2 cells exposed to a combination of hi...Objective Obesity-induced kidney injury contributes to the development of diabetic nephropathy(DN).Here,we identified the functions of ubiquitin-specific peptidase 19(USP19)in HK-2 cells exposed to a combination of high glucose(HG)and free fatty acid(FFA)and determined its association with TGF-beta-activated kinase 1(TAK1).Methods HK-2 cells were exposed to a combination of HG and FFA.USP19 mRNA expression was detected by quantitative RT-PCR(qRT-PCR),and protein analysis was performed by immunoblotting(IB).Cell growth was assessed by Cell Counting Kit-8(CCK-8)viability and 5-ethynyl-2′-deoxyuridine(EdU)proliferation assays.Cell cycle distribution and apoptosis were detected by flow cytometry.The USP19/TAK1 interaction and ubiquitinated TAK1 levels were assayed by coimmunoprecipitation(Co-IP)assays and IB.Results In HG+FFA-challenged HK-2 cells,USP19 was highly expressed.USP19 knockdown attenuated HG+FFA-triggered growth inhibition and apoptosis promotion in HK-2 cells.Moreover,USP19 knockdown alleviated HG+FFA-mediated PTEN-induced putative kinase 1(PINK1)/Parkin pathway inactivation and increased mitochondrial reactive oxygen species(ROS)generation in HK-2 cells.Mechanistically,USP19 stabilized the TAK1 protein through deubiquitination.Importantly,increased TAK1 expression reversed the USP19 knockdown-mediated phenotypic changes and PINK1/Parkin pathway activation in HG+FFA-challenged HK-2 cells.Conclusion The findings revealed that USP19 plays a crucial role in promoting HK-2 cell dysfunction induced by combined stimulation with HG and FFAs by stabilizing TAK1,providing a potential therapeutic strategy for combating DN.展开更多
Transforming growth factor-β （TGF-β） members are key cytokines that control embryogenesis and tissue homeostasis via transmembrane TGF-β type II （TβR II） and type I （TβRI） and serine/threonine kinases recep...Transforming growth factor-β （TGF-β） members are key cytokines that control embryogenesis and tissue homeostasis via transmembrane TGF-β type II （TβR II） and type I （TβRI） and serine/threonine kinases receptors. Aberrant activation of TGF-β signaling leads to diseases, including cancer. In advanced cancer, the TGF-β/SMAD pathway can act as an oncogenic factor driving tumor cell invasion and metastasis, and thus is considered to be a therapeutic target. The activity of TGF-β/SMAD pathway is known to be regulated by ubiquitination at multiple levels. As ubiquitination is reversible, emerging studies have uncovered key roles for ubiquitin-removals on TGF-β signaling components by deubiquitinating enzymes （DUBs）. In this paper, we summarize the latest findings on the DUBs that control the activity of the TGF-β signaling pathway. The regula- tory roles of these DUBs as a driving force for cancer progression as well as their underlying working mech- anisms are also discussed.展开更多
Maintenance of cell junctions plays a crucial role in the regulation of cellular functions including cell proliferation, permeability, and cell death. Disruption of cell junctions is implicated in a variety of human d...Maintenance of cell junctions plays a crucial role in the regulation of cellular functions including cell proliferation, permeability, and cell death. Disruption of cell junctions is implicated in a variety of human disorders, such as inflammatory diseases and cancers. Understanding molecular regulation of cell junctions is important for development of therapeutic strategies for intervention of human diseases. Ubiquitination is an important type of post-translational modification that primarily regulates endogenous protein stability, recep- tor internalization, enzyme activity, and protein-protein interactions. Ubiquitination is tightly regulated by ubiq- uitin E3 ligases and can be reversed by deubiquitinating enzymes. Recent studies have been focusing on inves- tigating the effect of protein stability in the regulation of cell-cell junctions. Ubiquitination and degradation of cadherins, claudins, and their interacting proteins are implicated in epithelial and endothelial barrier disruption. Recent studies have revealed that ubiquitination is involved in regulation of Rho GTPases＇ biological activities. Taken together these studies, ubiquitination plays a critical role in modulating cell junctions and motility. In this review, we will discuss the effects of ubiquitination and deubiquitination on protein stability and expression of key proteins in the cell-cell junctions, including junction proteins, their interacting proteins, and small Rho GTPases. We provide an overview of protein stability in modulation of epithelial and endothelial barrier integrity and introduce potential future search directions to better understand the effects of ubiquitination on human disorders caused by dysfunction of cell junctions.展开更多
As a key transcription factor in the brassinosteroid (BR) signaling pathway, the activity and expression ofBES1 (BRI1-EMS-SUPPRESSOR 1) are stringently regulated. BES1 degradation is mediated by ubiquitinrelated 26S p...As a key transcription factor in the brassinosteroid (BR) signaling pathway, the activity and expression ofBES1 (BRI1-EMS-SUPPRESSOR 1) are stringently regulated. BES1 degradation is mediated by ubiquitinrelated 26S proteasomal and autophagy pathways, which attenuate and terminate BR signaling;however,the opposing deubiquitinases (DUBs) are still unknown. Here, we showed that the ubp12-2w/13-3 doublemutant phenocopies the BR-deficient dwarf mutant, suggesting that the two DUBs UBP12/UBP13 antagonize ubiquitin-mediated degradation to stabilize BES1. These two DUBs can trim tetraubiquitin with K46 and K63 linkages in vitro. UBP12/BES1 and UBP13/BES1 complexes are localized in bothcytosol and nuclei. UBP12/13 can deubiquitinate polyubiquitinated BES1 in vitro and in planta, andUBP12 interacts with and deubiquitinates both inactive, phosphorylated BES1 and active, dephosphorylated BES1 in vivo. UBP12 overexpression in BES1OE plants significantly enhances cell elongation in hypocotyls and petioles and increases the ratio of leaf length to width compared with BES1OE or UBP12OE plants.Hypocotyl elongation and etiolation result from elevated BES1 levels because BES1 degradation is retardedby UBP12 in darkness or in light with BR. Protein degradation inhibitor experiments show that the majorityof BES1 can be degraded by either the proteasomal or the autophagy pathway, but a minor BES1 fractionremains pathway specific. In conclusion, UBP12/UBP13 deubiquitinate BES1 to stabilize the latter as a positive regulator for BR responses.展开更多
Prostate cancer(PCa)is the leading cause of cancer death in men.With more therapeutic modalities available,the overall survival in PCa has increased significantly in recent years.Patients with relapses after advanced ...Prostate cancer(PCa)is the leading cause of cancer death in men.With more therapeutic modalities available,the overall survival in PCa has increased significantly in recent years.Patients with relapses after advanced secondgeneration anti-androgen therapy however,often show poor disease prognosis.This group of patients often die from cancer-related complicacies.Multiple approaches have been taken to understand disease recurrence and to correlate the gene expression profile.In one such study,an 11-gene signature was identified to be associated with PCa recurrence and poor survival.Amongst them,a specific deubiquitinase called ubiquitin-specific peptidase 22(USP22)was selectively and progressively overexpressed with PCa progression.Subsequently,it was shown to regulate androgen receptors and Myc,the two most important regulators of PCa progression.Furthermore,USP22 has been shown to be associated with the development of therapy resistant PCa.Inhibiting USP22 was also found to be therapeutically advantageous,especially in clinically challenging and advanced PCa.This review provides an update of USP22 related functions and challenges associated with PCa research and explains why targeting this axis is beneficial for PCa relapse cases.展开更多
Infections by coronaviruses such as severe acute respiratory syndrome （SARS） coronavirus （SCoV） and mouse hepatitis virus A59 （MHV-A59） result in very little type I interferon （IFN） production by host cells, w...Infections by coronaviruses such as severe acute respiratory syndrome （SARS） coronavirus （SCoV） and mouse hepatitis virus A59 （MHV-A59） result in very little type I interferon （IFN） production by host cells, which is potentially responsible for the rapid viral growth and severe immunopathology associated with SARS. However, the molecular mechanisms for the low IFN production in cells infected with coronaviruses remain unclear. Here, we provide evidence that Papain-like protease domain 2 （PLP2）, a catalytic domain of the nonstructural protein 3 （nsp3） of MHV-A59, can bind to IRF3, cause its deubiquitination and prevent its nuclear translocation. As a consequence, co-expression of PLP2 strongly inhibits CARDIF-, TBK1- and IRF3-mediated IFNp reporter activities. In addition, we show that wild-type PLP2 but not the mutant PLP2 lacking the deubiquitinase （DUB） activity can reduce IFN induction and promote viral growth in cells infected with VSV. Thus, our study uncovered a viral DUB which coronaviruses may use to escape from the host innate antiviral responses.展开更多
Aim： To study the incidence of single nucleotide polymorphisms in ubiquitin-specific protease 26 （USP26） gene and its involvement in idiopathic male infertility in China. Methods： Routine semen analysis was perfor...Aim： To study the incidence of single nucleotide polymorphisms in ubiquitin-specific protease 26 （USP26） gene and its involvement in idiopathic male infertility in China. Methods： Routine semen analysis was performed. Infertility factors such as immunological, infectious and biochemical disorders were examined to select patients with idiopathic infertility. DNA was isolated from peripheral blood of the selected patients and control population, which were examined for mutations using polymerase chain reaction-single strand conformation polymorphism analysis. Furthermore, nucleotide sequences were sequenced in some patients and controls. Results： Of 41 infertile men, 9 （22.0%, P = 0.01） had changes in USP26 gene on the X chromosome. A compound mutation （364insACA; 460G→A） was detected in 8 patients （19.5%, P = 0.01） and a 1044T→A substitution was found in 1 patient （2.4%, P 〉 0.05）. All three variations led to changes in the coding amino acids. Two substitutions predict some changes： 460G→ A changes a valine into an isoleucine, and 1044T → A substitutes a leucine for a phenylalanine. Another insertion of three nucleotides ACA causes an insertion of threonine. No other changes were found in the remaining patients and fertile controls. Conclusion： The USP26 gene might be of importance in male reproduction. Mutations in this gene might be associated with male infertility, and might negatively affect testicular function. Further research on this issue is in progress.展开更多
Viral infection initiates a series of signaling cascades that activate the transcription factors nuclear factor kappa B and interferon regulatory factor 3, which collaborate to induce transcription of genes for type I...Viral infection initiates a series of signaling cascades that activate the transcription factors nuclear factor kappa B and interferon regulatory factor 3, which collaborate to induce transcription of genes for type I interferons （IFNs） and other cytokines. Here we report that the deubiquitinating enzyme ubiquitin-specific protease 17 （USP17） is required for virus-induced RIG-I- and melanoma differentiation-associated protein-5 （MDA5）-mediated type I IFN signaling. Knockdown of endogenous USP17 inhibited virus-, cytoplasmic poly（I：C）- and poly（dA：dT）-induced activation of the IFN-β promoter and cellular antiviral responses. We further found that knockdown of USP17 inhibited RIG-I- and MDA5-induced but not downstream activator-induced activation of the IFN-β promoter, which was correlated with an increase in ubiquitination levels of RIG-I and MDA5. Taken together, our findings suggest that USP17 functions through deubiquitination of RIG-I and MDA5 to regulate virus-induced type I IFN signaling.展开更多
Deubiquitinating enzymes （DUBs） play an important role in ubiquitin-dependent processes as negative regulators of protein ubiquitination. Ubiquitin-specific protease 26 （USP26） is a member of this family. The expr...Deubiquitinating enzymes （DUBs） play an important role in ubiquitin-dependent processes as negative regulators of protein ubiquitination. Ubiquitin-specific protease 26 （USP26） is a member of this family. The expression of Usp26 in mammalian testis and in other tissues has yet to be fully elucidated. To study the expression of Usp26 mRNA and protein in various murine tissues, reverse transcription （RT）-PCR and immunohistochemistry analyses were carried out. The RT-PCR analysis showed that the Usp26 transcript was expressed in all of the tested tissues. USP26 protein localization was examined by immunohistochemistry, and it was shown that USP26 was not detectable at 20 days postpartum, with the expression restricted to the cytoplasm of condensing spermatids （steps 9-16）, Leydig cells and nerve fibers in the brain. In addition, the USP26 protein was detected at moderate levels in myocardial ceils, the corpus of epidydimis, epithelium of the renal tubules and the seminal gland of postnatal day 35 mice. Its spatial and temporal expression pattern suggests that Usp26 may play an important role in development or function of the testis and brain. Further research into these possibilities is in progress.展开更多
Deubiquitination has emerged as an important mechanism of p53 regulation. A number of deubiquitinating enzymes(DUBs) from the ubiquitin-specific protease family have been shown to regulate the p53-MDM2-MDMX networks. ...Deubiquitination has emerged as an important mechanism of p53 regulation. A number of deubiquitinating enzymes(DUBs) from the ubiquitin-specific protease family have been shown to regulate the p53-MDM2-MDMX networks. We recently reported that Otub1, a DUB from the OTU-domain containing protease family, is a novel p53 regulator. Interestingly, Otub1 abrogates p53 ubiquitination and stabilizes and activates p53 in cells independently of its deubiquitinating enzyme activity. Instead, it does so by inhibiting the MDM2 cognate ubiquitin-conjugating enzyme(E2) UbcH5. Otub1 also regulates other biological signaling through this non-canonical mechanism, suppression of E2, including the inhibition of DNA-damage-induced chromatin ubiquitination. Thus, Otub1 evolves as a unique DUB that mainly suppresses E2 to regulate substrates. Here we review the current progress made towards the understanding of the complex regulation of the p53 tumor suppressor pathway by DUBs, the biological function of Otub1 including its positive regulation of p53, and the mechanistic insights into how Otub1 suppresses E2.展开更多
Dysregulation of components of the ubiqutin system has been linked to many diseases including melanoma. This is vital since the post-translational modification of different proteins via direct ubiquitin attachment is ...Dysregulation of components of the ubiqutin system has been linked to many diseases including melanoma. This is vital since the post-translational modification of different proteins via direct ubiquitin attachment is an important process for various cellular processes. CYLD is a tumor suppressor gene and deubiquitinating enzyme, which can remove polyubiquitin chains from their specific substrate and interfere with different signaling pathways. CYLD is frequently downregulated or even lost in melanoma cell lines or tissues compared to melanocytes. Down-regulation of CYLD leads to sustained oncogenic signaling that promotes melanoma progression and metastasis. In this review, we summarize the recent insights into the mechanisms which are responsible for the down-regulation of CYLD levels in melanoma and the signaling interactions of the CYLD gene product in melanoma. We argue that these recent insights into CYLD function invite the development of novel molecular strategies for melanoma prevention and treatment.展开更多
Programmed cell death ligand-1(PD-L1)is a T cell inhibitory immune checkpoint molecule that interacts with programmed cell death-1(PD-1)to promote immune escape of tumor cells.Compared with antibody therapies,small mo...Programmed cell death ligand-1(PD-L1)is a T cell inhibitory immune checkpoint molecule that interacts with programmed cell death-1(PD-1)to promote immune escape of tumor cells.Compared with antibody therapies,small molecule drugs show better prospects due to their advantages such as higher bioavailability,better tissue penetration,and reduced risk of immunogenicity.Here,we found that the small molecule demethylzeylasteral(Dem)can significantly downregulate the expression of PD-L1 in colorectal cancer cells and enhance the killing effect of T cells on tumor cells.Mechanistically,Dem binds to the deubiquitinating enzyme USP22 and promotes its degradation,resulting in increased ubiquitination and degradation of PD-L1 through the proteasome pathway.In addition,Dem increased the activity of cytotoxic T cells and reduced the number of myeloid-derived suppressor cells(MDSCs)and regulatory T cells(Tregs)in tumor-infiltrating lymphocytes(TILs),thereby activating the tumor immune microenvironment and inhibiting the growth of subcutaneous MC38 tumors in C57BL/6 mice.Moreover,we also found that the combination of Dem and CTLA4 antibodies can further improve the efficacy of antitumor therapy.Our study reveals the mechanism by which Dem promotes PD-L1 degradation and suggests that the combination of Dem and CTLA4 antibodies may improve the efficacy of immunotherapy.展开更多
Molecular glues are typically small chemical molecules that act at the interface between a target protein and degradation machinery to trigger ternary complex formation.Identifying molecular glues is challenging.There...Molecular glues are typically small chemical molecules that act at the interface between a target protein and degradation machinery to trigger ternary complex formation.Identifying molecular glues is challenging.There is a scarcity of target-specific upregulating molecular glues,which are highly anticipated for numerous targets,including P53.P53 is degraded in proteasomes through polyubiquitination by specific E3 ligases,whereas deubiquitinases(DUBs)remove polyubiquitination conjugates to counteract these E3ligases.Thus,small-molecular glues that enhance P53 anchoring to DUBs may stabilize P53 through deubiquitination.Here,using small-molecule microarray-based technology and unbiased screening,we identified three potential molecular glues that may tether P53 to the DUB,USP7,and elevate the P53 level.Among the molecular glues,bromocriptine(BC)is an FDA-approved drug with the most robust effects.BC was further verified to increase P53 stability via the predicted molecular glue mechanism engaging USP7.Consistent with P53 upregulation in cancer cells,BC was shown to inhibit the proliferation of cancer cells in vitro and suppress tumor growth in a xenograft model.In summary,we established a potential screening platform and identified potential molecular glues upregulating P53.Similar strategies could be applied to the identification of other types of molecular glues that may benefit drug discovery and chemical biology studies.展开更多
Ovarian cancer is a common cancer for females,and the incidence and mortality rates are on the rise.Many treatment strategies have been developed for ovarian cancer,including chemotherapy and immunotherapy,but they ar...Ovarian cancer is a common cancer for females,and the incidence and mortality rates are on the rise.Many treatment strategies have been developed for ovarian cancer,including chemotherapy and immunotherapy,but they are often ineffective and prone to drug resistance.Protein ubiquitination is an important class of post-translation modifications that have been found to be associated with various human diseases and cancer development.Recent studies have revealed that protein ubiquitination is involved in the progression of ovarian cancer and plays an important role in the tumor immune process.Moreover,the com-bination of ubiquitinase/deubiquitinase inhibitors and cancer immunotherapy approaches can effectively reduce treatment resistance and improve treatment efficacy,which provides new ideas for cancer treatment.Herein,we review the role of protein ubiquitination in relation to ovarian cancer immunotherapy and recent advances in the use of ubiquitinase/deubiquitinase inhibitorsin combil ationwitncaner mmunotherapy.展开更多
Background:Hepatocellular carcinoma(HCC)is one of the most prevalent cancers in the world,with a high likelihood of metastasis and a dismal prognosis.The reprogramming of glucosemetabolism is critical in the developme...Background:Hepatocellular carcinoma(HCC)is one of the most prevalent cancers in the world,with a high likelihood of metastasis and a dismal prognosis.The reprogramming of glucosemetabolism is critical in the development ofHCC.TheWarburg effect has recently been confirmed to occur in a variety of cancers,including HCC.However,little is known about the molecular biological mechanisms underlying the Warburg effect in HCC cells.In this study,we sought to better understand how methyltransferase 5,N6-adenosine(METTL5)controls the development of HCC and theWarburg effect.Methods:In the current study,quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of METTL5 in HCC tissues and cell lines.Several different cell models and animal models were established to determine the role of METTL5 in glucose metabolism reprogramming and the underlying molecularmechanism of HCC.Glutathione-S-transferase pulldown,coimmunoprecipitation,RNA sequencing,non-targeted metabolomics,polysome profiling,and luciferase reporter assays were performed to investigate the molecular mechanisms of METTL5 in HCC cells.Results:We discovered that METTL5 drove glucose metabolic reprogramming to promote the proliferation and metastasis of HCC.Mechanistically,upregulation of METTL5 promoted c-Myc stability and thus activated its downstream glycolytic genes lactate dehydrogenase A(LDHA),enolase 1(ENO1),triosephosphate isomerase 1(TPI1),solute carrier family 2 member 1(SLC2A1),and pyruvate kinase M2(PKM2).The c-Box and ubiquitin binding domain(UBA)regions of ubiquitin specific peptidase 5(USP5)binded to c-Myc protein and inhibited K48-linked polyubiquitination of c-Myc.Further study revealed that METTL5 controled the USP5 translation process,which in turn regulated the ubiquitination of c-Myc.Furthermore,we identified cAMP responsive element binding protein 1(CREB1)/P300 as a critical transcriptional regulator ofMETTL5 that promoted the transcription of METTL5 in HCC.In patient-derived tumor xenograft(PDX)models,adenovirus-mediated knockout of METTL5 had a good antitumor effect and prolonged the survival of PDX-bearing mice.Conclusions:These findings point to a novel mechanism by which CREB1/P300-METTL5-USP5-c-Myc controls abnormal glucose metabolism and promotes tumor growth,suggesting that METTL5 is a potential therapeutic target and prognostic biomarker for HCC.展开更多
Activity-based Ubiquitin probes(Ub-ABPs)carrying a reporter group have emerged as effective tools for the investigation of deubiquitinating enzymes(DUBs),such as studying the molecular mechanism of DUBs,profiling new ...Activity-based Ubiquitin probes(Ub-ABPs)carrying a reporter group have emerged as effective tools for the investigation of deubiquitinating enzymes(DUBs),such as studying the molecular mechanism of DUBs,profiling new DUBs.But so far,the synthesis of commonly used biotin-bearing Ub-ABPs is a technical challenge.Here,we report a one-pot semi-synthetic strategy for the acquiring of Ub-ABPs carrying a biotin tag through sequential enzymatic ligation,N-S acyl transfer and aminolysis reaction without any purification steps.These probes enable to capture the different family of DUBs for enrichment and immunoblotting using the attached biotin tag.展开更多
基金supported by the National Natural Science Foundation of China(grant number:32025003).
文摘Histone H2A monoubiquitination is associated with transcriptional repression and needs to be removed by deubiquitinases to facilitate gene transcription in eukaryotes.However,the deubiquitinase responsible for genome-wide H2A deubiquitination in plants has yet to be identified.In this study,we found that the previously identified PWWP-EPCR-ARID-TRB(PEAT)complex components interact with both the ubiquitin-specific protease UBP5 and the redundant histone acetyltransferases HAM1 and HAM2(HAM1/2)to form a larger version of PEAT complex in Arabidopsis thaliana.UBP5 functions as an H2A deubiquitinase in a nucleosome substrate-dependent manner in vitro and mediates H2A deubiquitination at the whole-genome level in vivo.HAM1/2 are shared subunits of the PEAT complex and the conserved NuA4 histone acetyltransferase com-plex,and are responsible for histone H4K5 acetylation.Within the PEAT complex,the PWWP components(PWWP1,PWWP2,and PWWP3)directly interact with UBP5 and are necessary for UBP5-mediated H2A deu-biquitination,while the EPCR components(EPCR1 and EPCR2)directly interact with HAM1/2 and are required for HAM1/2-mediated H4K5acetylation.Collectively,our study not onlyidentifies dual roles of thePEAT com-plex in H2A deubiquitination and H4K5 acetylation but also illustrates how these processes collaborate at the whole-genome level to regulate the transcription and development in plants.
基金supported by National Natural Science Foundation of China(No.U21A20420 to Bo Yang)Zhejiang Provincial Natural Science Foundation(No.LR22H310002 to Ji Cao,China)。
文摘Deubiquitinating enzymes(DUBs) or deubiquitinases facilitate the escape of multiple proteins from ubiquitin-proteasome degradation and are critical for regulating protein expression levels in vivo.Therefore,dissecting the underlying mechanism of DUB recognition is needed to advance the development of drugs related to DUB signaling pathways.To data,extensive studies on the ubiquitin chain specificity of DUBs have been reported,but substrate protein recognition is still not clearly understood.As a breakthrough,the scaffolding role may be significant to substrate protein selectivity.From this perspective,we systematically characterized the scaffolding proteins and complexes contributing to DUB substrate selectivity.Furthermore,we proposed a deubiquitination complex platform(DCP) as a potentially generic mechanism for DUB substrate recognition based on known examples,which might fill the gaps in the understanding of DUB substrate specificity.
基金supported by the National Natural Science Foundation of China(82103508,81871866,82173252)Shaanxi Special Support Plan-Program for Leading Talents of Science and Technology Innovation(China)(No.2019 Special Support Plan)+1 种基金the Natural Science Foundation of Shaanxi Province(China)(2016SF-308,2019SF-033,2022SF-145)Project of Tangdu Hospital,the Fourth Military Medical University(China)(No.2018 Key Talents).
文摘As members of the immune checkpoint family, PD-1 and its ligand PD-L1 play critical roles in maintaining the balance between autoimmunity and tolerance. The interaction of PD-1/PD-L1 is also involved in tumor evasion inside the tumor microenvironment, caused by reduced T cell activation, proliferation, cytotoxic secretion, and survival. Previous research has shown that the expression level of PD-1/PD-L1 may be regulated by ubiquitin-mediated proteasome degradation, which is an important mode of post-translational modification (PTM). PD-1/PD-L1 ubiquitin modification research in tumor immunotherapy is the subject of the present review, which aims to assess the most recent developments in this area. We offer a short explanation of PD-1/PD-L1 as well as some basic background information on the UPS system and discuss many routes that target E3s and DUBs, respectively, in the regulation of PD-1/PD-L1 in tumor immunotherapy. In addition, we offer numerous innovative prospective research areas for the future, as well as novel immunotherapy concepts and ideas. Taken together, the information compiled herein should serve as a comprehensive repository of information about tumor immunotherapy that is currently available, and it should be useful in the design of future studies, as well as the development of potential targets and strategies for future tumor immunotherapy.
基金supported by grants from Zhejiang Provincial Natural Science Foundation of China(LQ23H14003)National Natural Science Foundation of China(81472800,82173460)+1 种基金Department of Science and Technology of Shandong Province(2019GSF108083)Zhejiang Provincial Postdoctoral Scientific Research Project Funding(ZJ2022076),China.
文摘Objective:To investigate the effects and underlying mechanism of 2-hexyl-4-pentynoic acid(HPTA),a derivative of valproic acid(VPA),on radiotherapy in breast cancer.Methods:MCF7 cells and 7,12-dimethylbenz-[α]-anthracene(DMBA)-induced transformed human normal breast cells(MCF10A–DMBA cells)were irradiated with 8 Gy X-rays.For both cells there were four groups:control,valproic acid(VPA)/HPTA,IR,and VPA/HPTA+IR groups.MTT and clonogenic survival assays were performed to assess cell proliferation,and comet assay was performed to evaluate DNA damage.Protein expression ofγH2AX,53BP1,Rad51,and BRCA1 was examined via immunofluorescence and immunoblotting.Cycloheximide chase and ubiquitination experiments were conducted to determine Rad51 ubiquitination.In vivo experiments involved a rat model of DMBA-induced breast cancer,with four fractionated doses of 2 Gy.Tumor tissue pathological changes andγH2AX,Rad51,and UCHL3 expression levels were measured by hematoxylin-eosin staining,immunohistochemistry,and immunoblotting.Results:Compared with the IR group,15μmol/L HPTA reduced the cell proliferation ability of irradiated MCF7 cells(t=2.16,P<0.05).The VPA/HPTA+IR group exhibited significantly increased DNA double-strand breaks relative to those in the IR group(VPA+IR vs.IR,t=13.37,P<0.05;HPTA+IR vs.IR,t=8.48,P<0.05).Immunofluorescence and immunoblotting experiments demonstrated that the VPA/HPTA+IR group displayed signifi-cantly increased cell foci formation,γH2AX and 53BP1 protein expression levels compared to the IR group[(γH2AX:VPA+IR vs.IR,t=8.88,P<0.05;HPTA+IR vs.IR,t=8.90,P<0.05),(53BP1,VPA+IR vs.IR,t=5.73,P<0.05;HPTA+IR vs.IR,t=6.40,P<0.05)].Further,Rad51 expression was downregulated(VPA+IR vs.IR,t=3.12,P<0.05;HPTA+IR vs.IR,t=2.70,P<0.05),and Rad51 inhibition effectively counteracted HPTA-induced radiosensitization.Ubiquitination detection further verified that HPTA inhibits Rad51 expression via UCHL3-dependent Rad51 deubiquitination.In vivo study results showed that 20 mg/kg HPTA significantly enhanced the radiosensitivity of breast tumors in rats by inhibiting Rad51 expression.Conclusions:HPTA is a highly effective radiosensitizer that enhances the radiotherapeutic efficacy of breast cancer treatment through UCHL3-dependent deubiquitination of Rad51.
基金supported by Natural Science Foundation of Shaanxi Province(No.2023-JC-YB-743 and No.2021JQ-905).
文摘Objective Obesity-induced kidney injury contributes to the development of diabetic nephropathy(DN).Here,we identified the functions of ubiquitin-specific peptidase 19(USP19)in HK-2 cells exposed to a combination of high glucose(HG)and free fatty acid(FFA)and determined its association with TGF-beta-activated kinase 1(TAK1).Methods HK-2 cells were exposed to a combination of HG and FFA.USP19 mRNA expression was detected by quantitative RT-PCR(qRT-PCR),and protein analysis was performed by immunoblotting(IB).Cell growth was assessed by Cell Counting Kit-8(CCK-8)viability and 5-ethynyl-2′-deoxyuridine(EdU)proliferation assays.Cell cycle distribution and apoptosis were detected by flow cytometry.The USP19/TAK1 interaction and ubiquitinated TAK1 levels were assayed by coimmunoprecipitation(Co-IP)assays and IB.Results In HG+FFA-challenged HK-2 cells,USP19 was highly expressed.USP19 knockdown attenuated HG+FFA-triggered growth inhibition and apoptosis promotion in HK-2 cells.Moreover,USP19 knockdown alleviated HG+FFA-mediated PTEN-induced putative kinase 1(PINK1)/Parkin pathway inactivation and increased mitochondrial reactive oxygen species(ROS)generation in HK-2 cells.Mechanistically,USP19 stabilized the TAK1 protein through deubiquitination.Importantly,increased TAK1 expression reversed the USP19 knockdown-mediated phenotypic changes and PINK1/Parkin pathway activation in HG+FFA-challenged HK-2 cells.Conclusion The findings revealed that USP19 plays a crucial role in promoting HK-2 cell dysfunction induced by combined stimulation with HG and FFAs by stabilizing TAK1,providing a potential therapeutic strategy for combating DN.
文摘Transforming growth factor-β （TGF-β） members are key cytokines that control embryogenesis and tissue homeostasis via transmembrane TGF-β type II （TβR II） and type I （TβRI） and serine/threonine kinases receptors. Aberrant activation of TGF-β signaling leads to diseases, including cancer. In advanced cancer, the TGF-β/SMAD pathway can act as an oncogenic factor driving tumor cell invasion and metastasis, and thus is considered to be a therapeutic target. The activity of TGF-β/SMAD pathway is known to be regulated by ubiquitination at multiple levels. As ubiquitination is reversible, emerging studies have uncovered key roles for ubiquitin-removals on TGF-β signaling components by deubiquitinating enzymes （DUBs）. In this paper, we summarize the latest findings on the DUBs that control the activity of the TGF-β signaling pathway. The regula- tory roles of these DUBs as a driving force for cancer progression as well as their underlying working mech- anisms are also discussed.
文摘Maintenance of cell junctions plays a crucial role in the regulation of cellular functions including cell proliferation, permeability, and cell death. Disruption of cell junctions is implicated in a variety of human disorders, such as inflammatory diseases and cancers. Understanding molecular regulation of cell junctions is important for development of therapeutic strategies for intervention of human diseases. Ubiquitination is an important type of post-translational modification that primarily regulates endogenous protein stability, recep- tor internalization, enzyme activity, and protein-protein interactions. Ubiquitination is tightly regulated by ubiq- uitin E3 ligases and can be reversed by deubiquitinating enzymes. Recent studies have been focusing on inves- tigating the effect of protein stability in the regulation of cell-cell junctions. Ubiquitination and degradation of cadherins, claudins, and their interacting proteins are implicated in epithelial and endothelial barrier disruption. Recent studies have revealed that ubiquitination is involved in regulation of Rho GTPases＇ biological activities. Taken together these studies, ubiquitination plays a critical role in modulating cell junctions and motility. In this review, we will discuss the effects of ubiquitination and deubiquitination on protein stability and expression of key proteins in the cell-cell junctions, including junction proteins, their interacting proteins, and small Rho GTPases. We provide an overview of protein stability in modulation of epithelial and endothelial barrier integrity and introduce potential future search directions to better understand the effects of ubiquitination on human disorders caused by dysfunction of cell junctions.
基金This work was supported in part by an RSSS grant(no.NRF-RSSS-002)to N.-H.C.from the National Research Foundation,Singapore.
文摘As a key transcription factor in the brassinosteroid (BR) signaling pathway, the activity and expression ofBES1 (BRI1-EMS-SUPPRESSOR 1) are stringently regulated. BES1 degradation is mediated by ubiquitinrelated 26S proteasomal and autophagy pathways, which attenuate and terminate BR signaling;however,the opposing deubiquitinases (DUBs) are still unknown. Here, we showed that the ubp12-2w/13-3 doublemutant phenocopies the BR-deficient dwarf mutant, suggesting that the two DUBs UBP12/UBP13 antagonize ubiquitin-mediated degradation to stabilize BES1. These two DUBs can trim tetraubiquitin with K46 and K63 linkages in vitro. UBP12/BES1 and UBP13/BES1 complexes are localized in bothcytosol and nuclei. UBP12/13 can deubiquitinate polyubiquitinated BES1 in vitro and in planta, andUBP12 interacts with and deubiquitinates both inactive, phosphorylated BES1 and active, dephosphorylated BES1 in vivo. UBP12 overexpression in BES1OE plants significantly enhances cell elongation in hypocotyls and petioles and increases the ratio of leaf length to width compared with BES1OE or UBP12OE plants.Hypocotyl elongation and etiolation result from elevated BES1 levels because BES1 degradation is retardedby UBP12 in darkness or in light with BR. Protein degradation inhibitor experiments show that the majorityof BES1 can be degraded by either the proteasomal or the autophagy pathway, but a minor BES1 fractionremains pathway specific. In conclusion, UBP12/UBP13 deubiquitinate BES1 to stabilize the latter as a positive regulator for BR responses.
文摘Prostate cancer(PCa)is the leading cause of cancer death in men.With more therapeutic modalities available,the overall survival in PCa has increased significantly in recent years.Patients with relapses after advanced secondgeneration anti-androgen therapy however,often show poor disease prognosis.This group of patients often die from cancer-related complicacies.Multiple approaches have been taken to understand disease recurrence and to correlate the gene expression profile.In one such study,an 11-gene signature was identified to be associated with PCa recurrence and poor survival.Amongst them,a specific deubiquitinase called ubiquitin-specific peptidase 22(USP22)was selectively and progressively overexpressed with PCa progression.Subsequently,it was shown to regulate androgen receptors and Myc,the two most important regulators of PCa progression.Furthermore,USP22 has been shown to be associated with the development of therapy resistant PCa.Inhibiting USP22 was also found to be therapeutically advantageous,especially in clinically challenging and advanced PCa.This review provides an update of USP22 related functions and challenges associated with PCa research and explains why targeting this axis is beneficial for PCa relapse cases.
基金These authors contributed equally to this work. We thank Drs S Vaidya and E Chow （University of California Los Angeles, USA） for their help in setting up critical experimental systems. We greatly thank Dr K Holmes （University of Colorado Health Sciences Center, USA） for sharing with us 17C1-1 cell line and helping to optimize the protocol to produce high titered MHV-A59 virus stock. We also thank Drs R Baric and L Su （University of North Carolina, USA） for the gift of MHV-A59 and guidance of virus infection. We thank Dr K Lim （National Neuroscience Institute, Singapore） for the gift of Ubi plasmids. We thank Dr M Wathelet （University of Cincinnati College of Medicine, USA） for sharing the nsp3 construct. Also we thank Dr G Gao （Institute of Biophysics, CAS） for providing us with VSV. This research was partly supported by grants from the National Natural Science Foundation of China （30728006） to Genhong Cheng and the National Basic Research Program of MOST （2004BA519A61, 2006CB504300, 2007DFC30190） to Hong Tang.
文摘Infections by coronaviruses such as severe acute respiratory syndrome （SARS） coronavirus （SCoV） and mouse hepatitis virus A59 （MHV-A59） result in very little type I interferon （IFN） production by host cells, which is potentially responsible for the rapid viral growth and severe immunopathology associated with SARS. However, the molecular mechanisms for the low IFN production in cells infected with coronaviruses remain unclear. Here, we provide evidence that Papain-like protease domain 2 （PLP2）, a catalytic domain of the nonstructural protein 3 （nsp3） of MHV-A59, can bind to IRF3, cause its deubiquitination and prevent its nuclear translocation. As a consequence, co-expression of PLP2 strongly inhibits CARDIF-, TBK1- and IRF3-mediated IFNp reporter activities. In addition, we show that wild-type PLP2 but not the mutant PLP2 lacking the deubiquitinase （DUB） activity can reduce IFN induction and promote viral growth in cells infected with VSV. Thus, our study uncovered a viral DUB which coronaviruses may use to escape from the host innate antiviral responses.
基金Acknowledgment We thank the laboratory, clinical and paramedical staff of the center of Reproductive Medicine, and the Departmerit of Forensic Medicine, Pathology for their assistance. We especially thank Dr Sheng-Bin Li for practical support. This study was supported by National Natural Science Foundation of China （No. 30471735） and Science ＆ Technique Research Intensive Project of Education Ministry of China （No.105157） and Sci-Technical Development Project of Shaanxi Province, China （2005K15-G2, 2006K15-G4）.
文摘Aim： To study the incidence of single nucleotide polymorphisms in ubiquitin-specific protease 26 （USP26） gene and its involvement in idiopathic male infertility in China. Methods： Routine semen analysis was performed. Infertility factors such as immunological, infectious and biochemical disorders were examined to select patients with idiopathic infertility. DNA was isolated from peripheral blood of the selected patients and control population, which were examined for mutations using polymerase chain reaction-single strand conformation polymorphism analysis. Furthermore, nucleotide sequences were sequenced in some patients and controls. Results： Of 41 infertile men, 9 （22.0%, P = 0.01） had changes in USP26 gene on the X chromosome. A compound mutation （364insACA; 460G→A） was detected in 8 patients （19.5%, P = 0.01） and a 1044T→A substitution was found in 1 patient （2.4%, P 〉 0.05）. All three variations led to changes in the coding amino acids. Two substitutions predict some changes： 460G→ A changes a valine into an isoleucine, and 1044T → A substitutes a leucine for a phenylalanine. Another insertion of three nucleotides ACA causes an insertion of threonine. No other changes were found in the remaining patients and fertile controls. Conclusion： The USP26 gene might be of importance in male reproduction. Mutations in this gene might be associated with male infertility, and might negatively affect testicular function. Further research on this issue is in progress.
基金Acknowledgments We thank the members of our laboratory for discussions. This work was supported by grants from the National Basic Re- search Program of China （973 Program） （2006CB504301 and 2010CB911802） and the National Natural Science Foundation of China （30921001 and 30700417）.
文摘Viral infection initiates a series of signaling cascades that activate the transcription factors nuclear factor kappa B and interferon regulatory factor 3, which collaborate to induce transcription of genes for type I interferons （IFNs） and other cytokines. Here we report that the deubiquitinating enzyme ubiquitin-specific protease 17 （USP17） is required for virus-induced RIG-I- and melanoma differentiation-associated protein-5 （MDA5）-mediated type I IFN signaling. Knockdown of endogenous USP17 inhibited virus-, cytoplasmic poly（I：C）- and poly（dA：dT）-induced activation of the IFN-β promoter and cellular antiviral responses. We further found that knockdown of USP17 inhibited RIG-I- and MDA5-induced but not downstream activator-induced activation of the IFN-β promoter, which was correlated with an increase in ubiquitination levels of RIG-I and MDA5. Taken together, our findings suggest that USP17 functions through deubiquitination of RIG-I and MDA5 to regulate virus-induced type I IFN signaling.
基金Acknowledgment We thank the laboratory, clinical and paramedical staff of the center of Reproductive Medicine, and the Department of Pathology for their assistance. This study was supported by the National Natural Science Foundation of China （30471735 and 30700654） and the Sci-Technical Development Project of Shanxi Province, China （2006K 15-G4）.
文摘Deubiquitinating enzymes （DUBs） play an important role in ubiquitin-dependent processes as negative regulators of protein ubiquitination. Ubiquitin-specific protease 26 （USP26） is a member of this family. The expression of Usp26 in mammalian testis and in other tissues has yet to be fully elucidated. To study the expression of Usp26 mRNA and protein in various murine tissues, reverse transcription （RT）-PCR and immunohistochemistry analyses were carried out. The RT-PCR analysis showed that the Usp26 transcript was expressed in all of the tested tissues. USP26 protein localization was examined by immunohistochemistry, and it was shown that USP26 was not detectable at 20 days postpartum, with the expression restricted to the cytoplasm of condensing spermatids （steps 9-16）, Leydig cells and nerve fibers in the brain. In addition, the USP26 protein was detected at moderate levels in myocardial ceils, the corpus of epidydimis, epithelium of the renal tubules and the seminal gland of postnatal day 35 mice. Its spatial and temporal expression pattern suggests that Usp26 may play an important role in development or function of the testis and brain. Further research into these possibilities is in progress.
基金Supported by NIH/NCI,No.R00 CA127134 and No.R01CA160474a Department of Defense,No.W81XWH-10-1-1029,to Dai MSA Grant from Medical Research Foundation(MRF)of Oregon,to Sun XX
文摘Deubiquitination has emerged as an important mechanism of p53 regulation. A number of deubiquitinating enzymes(DUBs) from the ubiquitin-specific protease family have been shown to regulate the p53-MDM2-MDMX networks. We recently reported that Otub1, a DUB from the OTU-domain containing protease family, is a novel p53 regulator. Interestingly, Otub1 abrogates p53 ubiquitination and stabilizes and activates p53 in cells independently of its deubiquitinating enzyme activity. Instead, it does so by inhibiting the MDM2 cognate ubiquitin-conjugating enzyme(E2) UbcH5. Otub1 also regulates other biological signaling through this non-canonical mechanism, suppression of E2, including the inhibition of DNA-damage-induced chromatin ubiquitination. Thus, Otub1 evolves as a unique DUB that mainly suppresses E2 to regulate substrates. Here we review the current progress made towards the understanding of the complex regulation of the p53 tumor suppressor pathway by DUBs, the biological function of Otub1 including its positive regulation of p53, and the mechanistic insights into how Otub1 suppresses E2.
基金supported by the Swedish Society for Medical Research,Swedish Cancer Foundation,Swedish Medical Research Council,Royal Physiographic Society in Lund,BioCARE,Cancer Foundation,SUS Research Foundationsby funding from the European Research Council(ERC),under the European Union’s Seventh Framework Programme for Research and Technology Development,Grant Agreement No.[260460].
文摘Dysregulation of components of the ubiqutin system has been linked to many diseases including melanoma. This is vital since the post-translational modification of different proteins via direct ubiquitin attachment is an important process for various cellular processes. CYLD is a tumor suppressor gene and deubiquitinating enzyme, which can remove polyubiquitin chains from their specific substrate and interfere with different signaling pathways. CYLD is frequently downregulated or even lost in melanoma cell lines or tissues compared to melanocytes. Down-regulation of CYLD leads to sustained oncogenic signaling that promotes melanoma progression and metastasis. In this review, we summarize the recent insights into the mechanisms which are responsible for the down-regulation of CYLD levels in melanoma and the signaling interactions of the CYLD gene product in melanoma. We argue that these recent insights into CYLD function invite the development of novel molecular strategies for melanoma prevention and treatment.
基金funded by the National Key Research and Development Program of China(2022YFC3502000)National Natural Science Foundation of China(Nos.82141203,82374086,and 82104459)+3 种基金Shanghai Municipal Science and Technology Major Project(ZD2021CY001,China)Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine(ZYYCXTDD-202004,China)Science and Technology Commission of Shanghai Municipality(20YF1458700,China)Organizational Key Research and Development Program of Shanghai University of Traditional Chinese Medicine(2023YZZ02,China)。
文摘Programmed cell death ligand-1(PD-L1)is a T cell inhibitory immune checkpoint molecule that interacts with programmed cell death-1(PD-1)to promote immune escape of tumor cells.Compared with antibody therapies,small molecule drugs show better prospects due to their advantages such as higher bioavailability,better tissue penetration,and reduced risk of immunogenicity.Here,we found that the small molecule demethylzeylasteral(Dem)can significantly downregulate the expression of PD-L1 in colorectal cancer cells and enhance the killing effect of T cells on tumor cells.Mechanistically,Dem binds to the deubiquitinating enzyme USP22 and promotes its degradation,resulting in increased ubiquitination and degradation of PD-L1 through the proteasome pathway.In addition,Dem increased the activity of cytotoxic T cells and reduced the number of myeloid-derived suppressor cells(MDSCs)and regulatory T cells(Tregs)in tumor-infiltrating lymphocytes(TILs),thereby activating the tumor immune microenvironment and inhibiting the growth of subcutaneous MC38 tumors in C57BL/6 mice.Moreover,we also found that the combination of Dem and CTLA4 antibodies can further improve the efficacy of antitumor therapy.Our study reveals the mechanism by which Dem promotes PD-L1 degradation and suggests that the combination of Dem and CTLA4 antibodies may improve the efficacy of immunotherapy.
基金supported by the National Natural Science Foundation of China(82050008,92049301,81925012,32200797,32271510,32200602,and 82030106)the Science and Technology Commission of Shanghai Municipality(20JC1410900)+3 种基金Shanghai Municipal Science and Technology Key Laboratory Project(23dz2260100)the Innovation Program of Shanghai Municipal Education Commission(2021-01-07-00-07-E00074)the Shanghai Municipal Science and Technology Major Project(2018SHZDZX01)the China Postdoctoral Science Foundation(BX20200093 and 2021M690038)。
文摘Molecular glues are typically small chemical molecules that act at the interface between a target protein and degradation machinery to trigger ternary complex formation.Identifying molecular glues is challenging.There is a scarcity of target-specific upregulating molecular glues,which are highly anticipated for numerous targets,including P53.P53 is degraded in proteasomes through polyubiquitination by specific E3 ligases,whereas deubiquitinases(DUBs)remove polyubiquitination conjugates to counteract these E3ligases.Thus,small-molecular glues that enhance P53 anchoring to DUBs may stabilize P53 through deubiquitination.Here,using small-molecule microarray-based technology and unbiased screening,we identified three potential molecular glues that may tether P53 to the DUB,USP7,and elevate the P53 level.Among the molecular glues,bromocriptine(BC)is an FDA-approved drug with the most robust effects.BC was further verified to increase P53 stability via the predicted molecular glue mechanism engaging USP7.Consistent with P53 upregulation in cancer cells,BC was shown to inhibit the proliferation of cancer cells in vitro and suppress tumor growth in a xenograft model.In summary,we established a potential screening platform and identified potential molecular glues upregulating P53.Similar strategies could be applied to the identification of other types of molecular glues that may benefit drug discovery and chemical biology studies.
基金supported by the National Natural Science Foundation of China (No.82002751)the Medical Science and Technology Project of HenanProvince,China (No.SBGJ202102139)+3 种基金China Postdoctoral Science Foundation (No.2020M682361)Excellent Youth Foundation of Henan Province,China (No.222300420071)Outstanding Young Talents of Health Science and Technology Innovation of Henan Province,China (No.YXKC2022033)the Funding for Scientific Research and Innovation Team of The First Affiliated Hospital of Zhengzhou University,Henan,China (No.QNCXTD2023005).
文摘Ovarian cancer is a common cancer for females,and the incidence and mortality rates are on the rise.Many treatment strategies have been developed for ovarian cancer,including chemotherapy and immunotherapy,but they are often ineffective and prone to drug resistance.Protein ubiquitination is an important class of post-translation modifications that have been found to be associated with various human diseases and cancer development.Recent studies have revealed that protein ubiquitination is involved in the progression of ovarian cancer and plays an important role in the tumor immune process.Moreover,the com-bination of ubiquitinase/deubiquitinase inhibitors and cancer immunotherapy approaches can effectively reduce treatment resistance and improve treatment efficacy,which provides new ideas for cancer treatment.Herein,we review the role of protein ubiquitination in relation to ovarian cancer immunotherapy and recent advances in the use of ubiquitinase/deubiquitinase inhibitorsin combil ationwitncaner mmunotherapy.
基金the Ethics Committee of Zhongnan Hospital ofWuhan University(permit number:KELUN2017082 and KELUN2020100)The tissue samples were obtained with written informed consent from each patient.All animal experiments were approved in accordance with the guidelines of the Animal Ethics and Welfare Committee of Wuhan University of Zhongnan Hospital(permit number:ZN2022005).
文摘Background:Hepatocellular carcinoma(HCC)is one of the most prevalent cancers in the world,with a high likelihood of metastasis and a dismal prognosis.The reprogramming of glucosemetabolism is critical in the development ofHCC.TheWarburg effect has recently been confirmed to occur in a variety of cancers,including HCC.However,little is known about the molecular biological mechanisms underlying the Warburg effect in HCC cells.In this study,we sought to better understand how methyltransferase 5,N6-adenosine(METTL5)controls the development of HCC and theWarburg effect.Methods:In the current study,quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of METTL5 in HCC tissues and cell lines.Several different cell models and animal models were established to determine the role of METTL5 in glucose metabolism reprogramming and the underlying molecularmechanism of HCC.Glutathione-S-transferase pulldown,coimmunoprecipitation,RNA sequencing,non-targeted metabolomics,polysome profiling,and luciferase reporter assays were performed to investigate the molecular mechanisms of METTL5 in HCC cells.Results:We discovered that METTL5 drove glucose metabolic reprogramming to promote the proliferation and metastasis of HCC.Mechanistically,upregulation of METTL5 promoted c-Myc stability and thus activated its downstream glycolytic genes lactate dehydrogenase A(LDHA),enolase 1(ENO1),triosephosphate isomerase 1(TPI1),solute carrier family 2 member 1(SLC2A1),and pyruvate kinase M2(PKM2).The c-Box and ubiquitin binding domain(UBA)regions of ubiquitin specific peptidase 5(USP5)binded to c-Myc protein and inhibited K48-linked polyubiquitination of c-Myc.Further study revealed that METTL5 controled the USP5 translation process,which in turn regulated the ubiquitination of c-Myc.Furthermore,we identified cAMP responsive element binding protein 1(CREB1)/P300 as a critical transcriptional regulator ofMETTL5 that promoted the transcription of METTL5 in HCC.In patient-derived tumor xenograft(PDX)models,adenovirus-mediated knockout of METTL5 had a good antitumor effect and prolonged the survival of PDX-bearing mice.Conclusions:These findings point to a novel mechanism by which CREB1/P300-METTL5-USP5-c-Myc controls abnormal glucose metabolism and promotes tumor growth,suggesting that METTL5 is a potential therapeutic target and prognostic biomarker for HCC.
基金supported by the National Key R&D Program of China(No.2017YFA0505400)the National Natural Science Foundation of China(Nos.21877024,21972214 and 22277020)。
文摘Activity-based Ubiquitin probes(Ub-ABPs)carrying a reporter group have emerged as effective tools for the investigation of deubiquitinating enzymes(DUBs),such as studying the molecular mechanism of DUBs,profiling new DUBs.But so far,the synthesis of commonly used biotin-bearing Ub-ABPs is a technical challenge.Here,we report a one-pot semi-synthetic strategy for the acquiring of Ub-ABPs carrying a biotin tag through sequential enzymatic ligation,N-S acyl transfer and aminolysis reaction without any purification steps.These probes enable to capture the different family of DUBs for enrichment and immunoblotting using the attached biotin tag.
