Deubiquitinating enzymes(DUBs)are key enzymes capable of cleaving ubiquitin chains and synergizing with ubiquitination modifications to regulate the function of key proteins andmaintain normal physiological functions....Deubiquitinating enzymes(DUBs)are key enzymes capable of cleaving ubiquitin chains and synergizing with ubiquitination modifications to regulate the function of key proteins andmaintain normal physiological functions.OTUDs are a key subfamily of the ovarian tumor protease(OTU)family,with important DUB activities,and include mainly OTUD1,OTUD2,OTUD3,OTUD4,OTUD5,OTUD6A,and OTUD6B.In recent years,research on OTUD proteins has been gradually emphasized,and their aberrant expression has demonstrated significant research value in many diseases,such as cancer,immune abnormalities,neurological disorders,and embryonic developmental abnormalities.Therefore,a comprehensive understanding of the regulatory mechanisms of OTUD proteins and their use as therapeutic targets for diseases is of great value.This article focuses on the role of individual OTUD proteins in cancer progression and antiviral response.Importantly,in the context of cancer,we elaborate on their deubiquitinated protein targets and summarize the signaling mechanisms by which they promote or inhibit cancer progression.In the future,targeting OTUD proteins may become a therapeutic direction for cancer,and this review may be useful for research related to OTUD proteins and cancer.At present,there is a lack of research on targeted inhibitors or activators of OTUDs.More in vivo and in vitro studies on OTUDs may contribute to the development of inhibitors or agonists targeting OTUDs.Of course,when conducting these studies,researchers also need to pay attention to the impact of OTUDs on the host’s antiviral immune response.展开更多
DNA is the hereditary material in humans and almost all other organisms. It is essential for maintaining accurate transmission of genetic information. In the life cycle, DNA replication, cell division, or genome damag...DNA is the hereditary material in humans and almost all other organisms. It is essential for maintaining accurate transmission of genetic information. In the life cycle, DNA replication, cell division, or genome damage, including that caused by endogenous and exogenous agents, may cause DNA aberrations. Of all forms of DNA damage, DNA double-strand breaks(DSBs) are the most serious. If the repair function is defective, DNA damage may cause gene mutation, genome instability, and cell chromosome loss, which in turn can even lead to tumorigenesis. DNA damage can be repaired through multiple mechanisms. Homologous recombination(HR) and non-homologous end joining(NHEJ) are the two main repair mechanisms for DNA DSBs. Increasing amounts of evidence reveal that protein modifications play an essential role in DNA damage repair.Protein deubiquitination is a vital post-translational modification which removes ubiquitin molecules or polyubiquitinated chains from substrates in order to reverse the ubiquitination reaction. This review discusses the role of deubiquitinating enzymes(DUBs) in repairing DNA DSBs. Exploring the molecular mechanisms of DUB regulation in DSB repair will provide new insights to combat human diseases and develop novel therapeutic approaches.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
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
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
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
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
Doxorubicin(Dox)is an anthracycline drug widely applied in various malignancies.However,the fatal cardiotoxicity induced by Dox limits its clinical application.Post-transcriptional protein modification via ubiquitinat...Doxorubicin(Dox)is an anthracycline drug widely applied in various malignancies.However,the fatal cardiotoxicity induced by Dox limits its clinical application.Post-transcriptional protein modification via ubiquitination/deubiquitination in cardiomyocytes mediates the pathophysiological process in Dox-induced cardiotoxicity(DIC).In this study,we aimed to clarify the regulatory role and mechanism of a deubiquitinating enzyme,ubiquitin-specific peptidase 13(USP13),in DIC.RNA-seq analysis and experimental examinations identified that cardiomyocyte-derived USP13 positively correlated with DIC.Mice with cardiac-specific deletion of USP13 were subjected to Dox modeling.Adeno-associated virus serotype 9(AAV9)carrying cTNT promoter was constructed to overexpress USP13 in mouse heart tissues.Cardiomyocyte-specific knockout of USP13 exacerbated DIC,while its overexpression mitigated DIC in mice.Mechanistically,USP13 deubiquitinates the stimulator of interferon genes(STING)and promotes the autolysosome-related degradation of STING,subsequently alleviating cardiomyocyte inflammation and death.Our study suggests that USP13 serves a cardioprotective role in DIC and indicates USP13 as a potential therapeutic target for DIC treatment.展开更多
Recent studies have indicated that the expression of ubiquitin-specific protease 51(USP51),a novel deubiquitinating enzyme(DUB)that mediates protein degradation as part of the ubiquitin‒proteasome system(UPS),is assoc...Recent studies have indicated that the expression of ubiquitin-specific protease 51(USP51),a novel deubiquitinating enzyme(DUB)that mediates protein degradation as part of the ubiquitin‒proteasome system(UPS),is associated with tumor progression and therapeutic resistance in multiple malignancies.However,the underlying mechanisms and signaling networks involved in USP51-mediated regulation of malignant phenotypes remain largely unknown.The present study provides evidence of USP51's functions as the prominent DUB in chemoresistant triple-negative breast cancer(TNBC)cells.At the molecular level,ectopic expression of USP51 stabilized the 78 kDa Glucose-Regulated Protein(GRP78)protein through deubiquitination,thereby increasing its expression and localization on the cell surface.Furthermore,the upregulation of cell surface GRP78 increased the activity of ATP binding cassette subfamily B member 1(ABCB1),the main efflux pump of doxorubicin(DOX),ultimately decreasing its accumulation in TNBC cells and promoting the development of drug resistance both in vitro and in vivo.Clinically,we found significant correlations among USP51,GRP78,and ABCB1 expression in TNBC patients with chemoresistance.Elevated USP51,GRP78,and ABCB1 levels were also strongly associated with a poor patient prognosis.Importantly,we revealed an alternative intervention for specific pharmacological targeting of USP51 for TNBC cell chemosensitization.In conclusion,these findings collectively indicate that the USP51/GRP78/ABCB1 network is a key contributor to the malignant progression and chemotherapeutic resistance of TNBC cells,underscoring the pivotal role of USP51 as a novel therapeutic target for cancer management.展开更多
Acetaminophen(APAP)is the primary cause of drug-induced acute liver failure.Ovarian tumor deubiquitinase 6A(OTUD6A),a recently discovered deubiquitinase of the OTU family,has been primarily studied in tumor contexts.H...Acetaminophen(APAP)is the primary cause of drug-induced acute liver failure.Ovarian tumor deubiquitinase 6A(OTUD6A),a recently discovered deubiquitinase of the OTU family,has been primarily studied in tumor contexts.However,its role in APAP-induced liver injury(AILI)remains unclear.Therefore,this study aimed to investigate the involvement of OTUD6A in the pathogenesis of AILI.Our findings demonstrated a substantial upregulation of OTUD6A in both the liver tissue and isolated hepatocytes of mice following APAP stimulation.OTUD6A knockout exacerbated APAP-induced inflammation,hepatocyte necrosis,and liver injury,whereas OTUD6A overexpression alleviated these pathologies.Mechanistically,OTUD6A directly interacted with the enhancer of zeste homolog 2(EZH2)and selectively removed K48-linked polyubiquitin chains from EZH2,enhancing its stability.This resulted in increased protein levels of EZH2 and H3K27me3,as well as reduced endoplasmic reticulum(ER)stress and cell death in hepatocytes.Collectively,our research uncovers a novel role for OTUD6A in mitigating APAP-induced liver injury by promoting EZH2 stabilization.展开更多
Macrophage polarization to proinflammatory M1-like or anti-inflammatory M2-like cells is critical to mount a host defense or repair tissue.The exact molecular mechanisms controlling this process are still elusive.Here...Macrophage polarization to proinflammatory M1-like or anti-inflammatory M2-like cells is critical to mount a host defense or repair tissue.The exact molecular mechanisms controlling this process are still elusive.Here,we report that ubiquitin-specific protease 19(USP19)acts as an anti-inflammatory switch that inhibits inflammatory responses and promotes M2-like macrophage polarization.USP19 inhibited NLRP3 inflammasome activation by increasing autophagy flux and decreasing the generation of mitochondrial reactive oxygen species.In addition,USP19 inhibited the proteasomal degradation of inflammasome-independent NLRP3 by cleaving its polyubiquitin chains.USP19-stabilized NLRP3 promoted M2-like macrophage polarization by direct association with interferon regulatory factor 4,thereby preventing its p62-mediated selective autophagic degradation.Consistent with these observations,compared to wild-type mice,Usp19−/−mice had decreased M2-like macrophage polarization and increased interleukin-1βsecretion,in response to alum and chitin injections.Thus,we have uncovered an unexpected mechanism by which USP19 switches the proinflammatory function of NLRP3 into an anti-inflammatory function,and suggest that USP19 is a potential therapeutic target for inflammatory interventions.展开更多
MCP-1-induced protein-1(MCPIP1)is a newly identified protein that is crucial to immune regulation.Mice lack-ing MCPIP1 gene suffer from severe immune disorders,and most of them cannot survive longer than 12 weeks.Cons...MCP-1-induced protein-1(MCPIP1)is a newly identified protein that is crucial to immune regulation.Mice lack-ing MCPIP1 gene suffer from severe immune disorders,and most of them cannot survive longer than 12 weeks.Considerable progress has been made in revealing the mechanism underlying the immune regulatory function of MCPIP1.MCPIP1 can act as an RNase to promote the mRNA degradation of some inflammatory cytokines,such as IL-6 and IL-1.Pre-microRNAs are also confirmed to be the substrate of MCPIP1 RNase.The structure of MCPIP1 N-terminal conserved domain shows a PilT N-terminus-like RNase structure,further supporting the notion that MCPIP1 has RNase activity.MCPIP1 can also deubiquitinate TNF receptor-associated factor family proteins,which are known to mediate immune and inflammatory responses.In this review,we summarize recent progress on the immune regulatory role of MCPIP1 and discuss the mechanisms underlying its function.展开更多
The C-terminal conjugate of ubiquitin with 7-amino-4-methylcoumarin （Ub-AMC） is an important probe for fluorescencebased analysis of deubiquitinating enzyme （DUB） activity. It is important to develop more efficien...The C-terminal conjugate of ubiquitin with 7-amino-4-methylcoumarin （Ub-AMC） is an important probe for fluorescencebased analysis of deubiquitinating enzyme （DUB） activity. It is important to develop more efficient methods for the preparation of Ub-AMC because the currently available technology is still expensive for scaled-up production. In the present work we report an efficient strategy for total chemical synthesis of Ub-AMC through ligation of peptide hydrazides. Three peptide segments are assembled via N-to-C sequential ligation and the resulting product is converted to Ub-AMC via TCEP-mediated desulfurization. The synthetic Ub-AMC is shown to have expected biological functions throug展开更多
The transcription factor c-MYC(MYC thereafter)controls diverse transcription programs and plays a key role in the development of many human cancers.Cells develop multiple mechanisms to ensure that MYC levels and activ...The transcription factor c-MYC(MYC thereafter)controls diverse transcription programs and plays a key role in the development of many human cancers.Cells develop multiple mechanisms to ensure that MYC levels and activity are precisely controlled in normal physiological context.As a short half-lived protein,MYC protein levels are tightly regulated by the ubiquitin proteasome system.Over a dozen of ubiquitin ligases have been found to ubiquitinate MYC whereas a number of deubiquitinating enzymes counteract this process.Recent studies show that SUMOylation and deSUMOylation can also regulate MYC protein stability and activity.Interestingly,evidence suggests an intriguing crosstalk between MYC ubiquitination and SUMOylation.Deregulation of the MYC ubiquitination-SUMOylation regulatory network may contribute to tumorigenesis.This review is intended to provide the current understanding of the complex regulation of the MYC biology by dynamic ubiquitination and SUMOylation and their crosstalk.展开更多
MINDY-1 is a recently discovered new family of deubiquitinating enzymes(DUB),but one of its yeast homologs,YGL082 W,does not show any DUB activity in vitro.Sequence alignment shows that YGL082 W possesses the correct ...MINDY-1 is a recently discovered new family of deubiquitinating enzymes(DUB),but one of its yeast homologs,YGL082 W,does not show any DUB activity in vitro.Sequence alignment shows that YGL082 W possesses the correct catalytic triad,and yet did not catalyze either the hydrolysis of di-ubiquitin,crosslinking with C-terminally propargylated ubiquitin,or hydrolysis of ubiquitin-7-amino-4-methylcoumarin.After obtaining a crystal structure of the catalytic domain of YGL082 W,we identified an interesting difference between the catalytic center loop of YGL082 W and that of its human homolog MINDY-1.Because the conformation of the catalytic center loop was previously reported to be important for the deubiquitination activity of MINDY-1,we hypothesized that Glu27(instead of the corresponding Pro136 in MINDY-1) of the catalytic center loop of YGL082 W may impair the conformational change and account for the lack of activity.This hypothesis was supported by homology modeling and molecular dynamics simulations,which showed that the Pro-to-Glu mutation(P136 E mutation for MINDY-1) creates a hydrogen bond that inhibits the conformation change of the catalytic center loop of MINDY-1.Further experiments through site-directed mutation validated this hypothesis,showing that the P27 E mutation caused MIY1(a homologous active DUB from yeast) to lose activity.展开更多
文摘Deubiquitinating enzymes(DUBs)are key enzymes capable of cleaving ubiquitin chains and synergizing with ubiquitination modifications to regulate the function of key proteins andmaintain normal physiological functions.OTUDs are a key subfamily of the ovarian tumor protease(OTU)family,with important DUB activities,and include mainly OTUD1,OTUD2,OTUD3,OTUD4,OTUD5,OTUD6A,and OTUD6B.In recent years,research on OTUD proteins has been gradually emphasized,and their aberrant expression has demonstrated significant research value in many diseases,such as cancer,immune abnormalities,neurological disorders,and embryonic developmental abnormalities.Therefore,a comprehensive understanding of the regulatory mechanisms of OTUD proteins and their use as therapeutic targets for diseases is of great value.This article focuses on the role of individual OTUD proteins in cancer progression and antiviral response.Importantly,in the context of cancer,we elaborate on their deubiquitinated protein targets and summarize the signaling mechanisms by which they promote or inhibit cancer progression.In the future,targeting OTUD proteins may become a therapeutic direction for cancer,and this review may be useful for research related to OTUD proteins and cancer.At present,there is a lack of research on targeted inhibitors or activators of OTUDs.More in vivo and in vitro studies on OTUDs may contribute to the development of inhibitors or agonists targeting OTUDs.Of course,when conducting these studies,researchers also need to pay attention to the impact of OTUDs on the host’s antiviral immune response.
基金supported by the National Natural Science Foundation of China (Nos. 91749115 and 81872298)the Natural Science Foundation of Jiangxi Province (No. 20181BAB205044), China。
文摘DNA is the hereditary material in humans and almost all other organisms. It is essential for maintaining accurate transmission of genetic information. In the life cycle, DNA replication, cell division, or genome damage, including that caused by endogenous and exogenous agents, may cause DNA aberrations. Of all forms of DNA damage, DNA double-strand breaks(DSBs) are the most serious. If the repair function is defective, DNA damage may cause gene mutation, genome instability, and cell chromosome loss, which in turn can even lead to tumorigenesis. DNA damage can be repaired through multiple mechanisms. Homologous recombination(HR) and non-homologous end joining(NHEJ) are the two main repair mechanisms for DNA DSBs. Increasing amounts of evidence reveal that protein modifications play an essential role in DNA damage repair.Protein deubiquitination is a vital post-translational modification which removes ubiquitin molecules or polyubiquitinated chains from substrates in order to reverse the ubiquitination reaction. This review discusses the role of deubiquitinating enzymes(DUBs) in repairing DNA DSBs. Exploring the molecular mechanisms of DUB regulation in DSB repair will provide new insights to combat human diseases and develop novel therapeutic approaches.
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 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.
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 National Natural Science Foundation of China(82271347 to Gaojun Wu and U24A20814 to Guang Liang).
文摘Doxorubicin(Dox)is an anthracycline drug widely applied in various malignancies.However,the fatal cardiotoxicity induced by Dox limits its clinical application.Post-transcriptional protein modification via ubiquitination/deubiquitination in cardiomyocytes mediates the pathophysiological process in Dox-induced cardiotoxicity(DIC).In this study,we aimed to clarify the regulatory role and mechanism of a deubiquitinating enzyme,ubiquitin-specific peptidase 13(USP13),in DIC.RNA-seq analysis and experimental examinations identified that cardiomyocyte-derived USP13 positively correlated with DIC.Mice with cardiac-specific deletion of USP13 were subjected to Dox modeling.Adeno-associated virus serotype 9(AAV9)carrying cTNT promoter was constructed to overexpress USP13 in mouse heart tissues.Cardiomyocyte-specific knockout of USP13 exacerbated DIC,while its overexpression mitigated DIC in mice.Mechanistically,USP13 deubiquitinates the stimulator of interferon genes(STING)and promotes the autolysosome-related degradation of STING,subsequently alleviating cardiomyocyte inflammation and death.Our study suggests that USP13 serves a cardioprotective role in DIC and indicates USP13 as a potential therapeutic target for DIC treatment.
基金supported by grants from the International Science and Technology Cooperation Project of China(No.2022YFE0133300)the National Natural Science Foundation of China(No.82472870 and No.82172801).
文摘Recent studies have indicated that the expression of ubiquitin-specific protease 51(USP51),a novel deubiquitinating enzyme(DUB)that mediates protein degradation as part of the ubiquitin‒proteasome system(UPS),is associated with tumor progression and therapeutic resistance in multiple malignancies.However,the underlying mechanisms and signaling networks involved in USP51-mediated regulation of malignant phenotypes remain largely unknown.The present study provides evidence of USP51's functions as the prominent DUB in chemoresistant triple-negative breast cancer(TNBC)cells.At the molecular level,ectopic expression of USP51 stabilized the 78 kDa Glucose-Regulated Protein(GRP78)protein through deubiquitination,thereby increasing its expression and localization on the cell surface.Furthermore,the upregulation of cell surface GRP78 increased the activity of ATP binding cassette subfamily B member 1(ABCB1),the main efflux pump of doxorubicin(DOX),ultimately decreasing its accumulation in TNBC cells and promoting the development of drug resistance both in vitro and in vivo.Clinically,we found significant correlations among USP51,GRP78,and ABCB1 expression in TNBC patients with chemoresistance.Elevated USP51,GRP78,and ABCB1 levels were also strongly associated with a poor patient prognosis.Importantly,we revealed an alternative intervention for specific pharmacological targeting of USP51 for TNBC cell chemosensitization.In conclusion,these findings collectively indicate that the USP51/GRP78/ABCB1 network is a key contributor to the malignant progression and chemotherapeutic resistance of TNBC cells,underscoring the pivotal role of USP51 as a novel therapeutic target for cancer management.
基金supported by the Medical and Health Science Research Project of Zhejiang Province(2022KY348 to Wei Zuo and 2023XY164 to Lijiang Huang,China)th e Key Research Project of Wenzhou City(ZY2021021 to Yi Wang,China).
文摘Acetaminophen(APAP)is the primary cause of drug-induced acute liver failure.Ovarian tumor deubiquitinase 6A(OTUD6A),a recently discovered deubiquitinase of the OTU family,has been primarily studied in tumor contexts.However,its role in APAP-induced liver injury(AILI)remains unclear.Therefore,this study aimed to investigate the involvement of OTUD6A in the pathogenesis of AILI.Our findings demonstrated a substantial upregulation of OTUD6A in both the liver tissue and isolated hepatocytes of mice following APAP stimulation.OTUD6A knockout exacerbated APAP-induced inflammation,hepatocyte necrosis,and liver injury,whereas OTUD6A overexpression alleviated these pathologies.Mechanistically,OTUD6A directly interacted with the enhancer of zeste homolog 2(EZH2)and selectively removed K48-linked polyubiquitin chains from EZH2,enhancing its stability.This resulted in increased protein levels of EZH2 and H3K27me3,as well as reduced endoplasmic reticulum(ER)stress and cell death in hepatocytes.Collectively,our research uncovers a novel role for OTUD6A in mitigating APAP-induced liver injury by promoting EZH2 stabilization.
基金This work was supported by the National Key Research and Development Project(2020YFA0908700)the National Natural Science Foundation of China(31870862 and 31700760).
文摘Macrophage polarization to proinflammatory M1-like or anti-inflammatory M2-like cells is critical to mount a host defense or repair tissue.The exact molecular mechanisms controlling this process are still elusive.Here,we report that ubiquitin-specific protease 19(USP19)acts as an anti-inflammatory switch that inhibits inflammatory responses and promotes M2-like macrophage polarization.USP19 inhibited NLRP3 inflammasome activation by increasing autophagy flux and decreasing the generation of mitochondrial reactive oxygen species.In addition,USP19 inhibited the proteasomal degradation of inflammasome-independent NLRP3 by cleaving its polyubiquitin chains.USP19-stabilized NLRP3 promoted M2-like macrophage polarization by direct association with interferon regulatory factor 4,thereby preventing its p62-mediated selective autophagic degradation.Consistent with these observations,compared to wild-type mice,Usp19−/−mice had decreased M2-like macrophage polarization and increased interleukin-1βsecretion,in response to alum and chitin injections.Thus,we have uncovered an unexpected mechanism by which USP19 switches the proinflammatory function of NLRP3 into an anti-inflammatory function,and suggest that USP19 is a potential therapeutic target for inflammatory interventions.
基金supported by grants from the National Basic Research Program(973 Program)(Nos.2011CB915501 and 2011CB910304).
文摘MCP-1-induced protein-1(MCPIP1)is a newly identified protein that is crucial to immune regulation.Mice lack-ing MCPIP1 gene suffer from severe immune disorders,and most of them cannot survive longer than 12 weeks.Considerable progress has been made in revealing the mechanism underlying the immune regulatory function of MCPIP1.MCPIP1 can act as an RNase to promote the mRNA degradation of some inflammatory cytokines,such as IL-6 and IL-1.Pre-microRNAs are also confirmed to be the substrate of MCPIP1 RNase.The structure of MCPIP1 N-terminal conserved domain shows a PilT N-terminus-like RNase structure,further supporting the notion that MCPIP1 has RNase activity.MCPIP1 can also deubiquitinate TNF receptor-associated factor family proteins,which are known to mediate immune and inflammatory responses.In this review,we summarize recent progress on the immune regulatory role of MCPIP1 and discuss the mechanisms underlying its function.
基金National Basic Research Program of China (973 program, 2013CB932800)the National Natural Science Foundation of China (NSFC, 31100524 to M.Z., 31170817 for C.T., and 20972148 to L.L.)
文摘The C-terminal conjugate of ubiquitin with 7-amino-4-methylcoumarin （Ub-AMC） is an important probe for fluorescencebased analysis of deubiquitinating enzyme （DUB） activity. It is important to develop more efficient methods for the preparation of Ub-AMC because the currently available technology is still expensive for scaled-up production. In the present work we report an efficient strategy for total chemical synthesis of Ub-AMC through ligation of peptide hydrazides. Three peptide segments are assembled via N-to-C sequential ligation and the resulting product is converted to Ub-AMC via TCEP-mediated desulfurization. The synthetic Ub-AMC is shown to have expected biological functions throug
基金We thank members of the Dai and Sears laboratories for active discussion.This work was supported by NIH/NCI grant R01 CA186241 to M-S.D.and R.S.
文摘The transcription factor c-MYC(MYC thereafter)controls diverse transcription programs and plays a key role in the development of many human cancers.Cells develop multiple mechanisms to ensure that MYC levels and activity are precisely controlled in normal physiological context.As a short half-lived protein,MYC protein levels are tightly regulated by the ubiquitin proteasome system.Over a dozen of ubiquitin ligases have been found to ubiquitinate MYC whereas a number of deubiquitinating enzymes counteract this process.Recent studies show that SUMOylation and deSUMOylation can also regulate MYC protein stability and activity.Interestingly,evidence suggests an intriguing crosstalk between MYC ubiquitination and SUMOylation.Deregulation of the MYC ubiquitination-SUMOylation regulatory network may contribute to tumorigenesis.This review is intended to provide the current understanding of the complex regulation of the MYC biology by dynamic ubiquitination and SUMOylation and their crosstalk.
基金supported by the National Key Research and Development Program of China(2017YFA0505200)the National Natural Science Foundation of China(21532004,91753205,81621002,21621003)Shanghai Tech University
文摘MINDY-1 is a recently discovered new family of deubiquitinating enzymes(DUB),but one of its yeast homologs,YGL082 W,does not show any DUB activity in vitro.Sequence alignment shows that YGL082 W possesses the correct catalytic triad,and yet did not catalyze either the hydrolysis of di-ubiquitin,crosslinking with C-terminally propargylated ubiquitin,or hydrolysis of ubiquitin-7-amino-4-methylcoumarin.After obtaining a crystal structure of the catalytic domain of YGL082 W,we identified an interesting difference between the catalytic center loop of YGL082 W and that of its human homolog MINDY-1.Because the conformation of the catalytic center loop was previously reported to be important for the deubiquitination activity of MINDY-1,we hypothesized that Glu27(instead of the corresponding Pro136 in MINDY-1) of the catalytic center loop of YGL082 W may impair the conformational change and account for the lack of activity.This hypothesis was supported by homology modeling and molecular dynamics simulations,which showed that the Pro-to-Glu mutation(P136 E mutation for MINDY-1) creates a hydrogen bond that inhibits the conformation change of the catalytic center loop of MINDY-1.Further experiments through site-directed mutation validated this hypothesis,showing that the P27 E mutation caused MIY1(a homologous active DUB from yeast) to lose activity.
