UBE2O is a distinctive ubiquitin-conjugating enzyme characterized by its large size(1292 residues)and dual E2/E3 enzymatic activities,enabling diverse ubiquitylation types.Unlike typical E2 enzymes(150~200 residues),U...UBE2O is a distinctive ubiquitin-conjugating enzyme characterized by its large size(1292 residues)and dual E2/E3 enzymatic activities,enabling diverse ubiquitylation types.Unlike typical E2 enzymes(150~200 residues),UBE2O’s multifunctionality allows it to regulate substrate degradation,subcellular localization,and functional modulation.Emerging studies highlight its critical roles in protein quality control,erythroid differentiation,metabolic regulation,and maintenance of circadian rhythm.Dysregulation of UBE2O is implicated in various diseases,including cancers,neurodegenerative disorders,and metabolic diseases.This review extensively discusses the unique structural features,diverse biological functions,and pathological roles of UBE2O,as well as its therapeutic potential for associated diseases.展开更多
Developing and identifying effective medications and targets for treating hepatic fibrosis is an urgent priority.Our previous research demonstrated the efficacy of artesunate(ART)in alleviating liver fibrosis by elimi...Developing and identifying effective medications and targets for treating hepatic fibrosis is an urgent priority.Our previous research demonstrated the efficacy of artesunate(ART)in alleviating liver fibrosis by eliminating activated hepatic stellate cells(HSCs).However,the underlying mechanism remains unclear despite these findings.Notably,endocytic adaptor protein(NUMB)has significant implications for treating hepatic diseases,but current research primarily focuses on liver regeneration and hepatocellular carcinoma.The precise function of NUMB in liver fibrosis,particularly its ability to regulate HSCs,requires further investigation.This study aims to elucidate the role of NUMB in the anti-hepatic fibrosis action of ART in HSCs.We observed that the expression level of NUMB significantly decreased in activated HSCs compared to quiescent HSCs,exhibiting a negative correlation with the progression of liver fibrosis.Additionally,ART induced senescence in activated HSCs through the NUMB/P53 tumor suppressor(P53)axis.We identified NUMB as a crucial regulator of senescence in activated HSCs and as a mediator of ART in determining cell fate.This research examines the specific target of ART in eliminating activated HSCs,providing both theoretical and experimental evidence for the treatment of liver fibrosis.展开更多
The ubiquitin system is crucial for the development and fitness of higher plants.De-etiolation, during which green plants initiate photomorphogenesis and establish autotrophy, is a dramatic and complicated process tha...The ubiquitin system is crucial for the development and fitness of higher plants.De-etiolation, during which green plants initiate photomorphogenesis and establish autotrophy, is a dramatic and complicated process that is tightly regulated by a massive number of ubiquitylation/de-ubiquitylation events. Here we present site-specific quantitative proteomic data for the ubiquitylomes of de-etiolating seedling leaves of Zea mays L.(exposed to light for 1, 6, or 12 h)achieved through immunoprecipitation-based high-resolution mass spectrometry(MS). Through the integrated analysis of multiple ubiquitylomes, we identified and quantified 1926 unique ubiquitylation sites corresponding to 1053 proteins. We analyzed these sites and found five potential ubiquitylation motifs, KA, AXK, KXG, AK, and TK. Time-course studies revealed that the ubiquitylation levels of 214 sites corresponding to 173 proteins were highly correlated across two replicate MS experiments, and significant alterations in the ubiquitylation levels of 78 sites(fold change >1.5) were detected after de-etiolation for 12 h. The majority of the ubiquitylated sites we identified corresponded to substrates involved in protein and DNA metabolism, such as ribosomes and histones.Meanwhile, multiple ubiquitylation sites were detected in proteins whose functions reflect the major physiological changes that occur during plant de-etiolation, such as hormone synthesis/signaling proteins, key C4 photosynthetic enzymes, and light signaling proteins. This study on the ubiquitylome of the maize seedling leaf is the first attempt ever to study the ubiquitylome of a C4 plant and provides the proteomic basis for elucidating the role of ubiquitylation during plant de-etiolation.展开更多
Histone ubiquitylation has emerged as an important chromatin modification associated with DNA damage signaling and repair pathways.These histone marks,laid down by E3 ubiquitin ligases that include RNF8 and RNF168,dec...Histone ubiquitylation has emerged as an important chromatin modification associated with DNA damage signaling and repair pathways.These histone marks,laid down by E3 ubiquitin ligases that include RNF8 and RNF168,decorate chromatin domains surrounding DNA double-strand breaks(DSBs).Recent work implicated ubiquitylated histones in orchestrating cell cycle checkpoints,DNA repair and gene transcription.Here we summarize recent advances that contribute to our current knowledge of the highly dynamic nature of DSB-associated histone ubiquitylation,and discuss major challenges ahead in understanding the versatility of ubiquitin conjugation in maintaining genome stability.展开更多
Stroke is the second leading cause of death worldwide,and oxidative stress plays a crucial role.Celastrol exhibits strong antioxidant properties in several diseases;however,whether it can affect oxidation in cerebral ...Stroke is the second leading cause of death worldwide,and oxidative stress plays a crucial role.Celastrol exhibits strong antioxidant properties in several diseases;however,whether it can affect oxidation in cerebral ischemic-reperfusion injury(CIRI)remains unclear.This study aimed to determine whether celastrol could reduce oxidative damage during CIRI and to elucidate the underlying mechanisms.Here,we found that celastrol attenuated oxidative injury in CIRI by upregulating nuclear factor E2-related factor 2(Nrf2).Using alkynyl-tagged celastrol and liquid chromatography-tandem mass spectrometry,we showed that celastrol directly bound to neuronally expressed developmentally downregulated 4(Nedd4)and then released Nrf2 from Nedd4 in astrocytes.Nedd4 promoted the degradation of Nrf2 through K48-linked ubiquitination and thus contributed to astrocytic reactive oxygen species production in CIRI,which was significantly blocked by celastrol.Furthermore,by inhibiting oxidative stress and astrocyte activation,celastrol effectively rescued neurons from axon damage and apoptosis.Our study uncovered Nedd4 as a direct target of celastrol,and that celastrol exerts an antioxidative effect on astrocytes by inhibiting the interaction between Nedd4 and Nrf2 and reducing Nrf2 degradation in CIRI.展开更多
E3 ubiquitin ligases catalyze the final step of ubiquitylation,a crucial post-translational modification involved in almost every process in eukaryotic cells.E3 ubiquitin ligases are key regulators of cellular events,...E3 ubiquitin ligases catalyze the final step of ubiquitylation,a crucial post-translational modification involved in almost every process in eukaryotic cells.E3 ubiquitin ligases are key regulators of cellular events,and the investigation into their functions and functioning mechanisms are research areas with great importance.Synthetic or semi-synthetic tools have greatly facilitated the research about the enzyme activity,distribution in different physiological events,and catalytic mechanism of E3 ubiquitin ligase.In this review,we summarize the development of chemical tools for E3 ubiquitin ligases with an emphasis on the synthetic routes.We show the utility of these chemical tools by briefly discussing their applications in biological research.展开更多
Post-transcriptional epigenetic modifications provide numerous implications for tumor progression,metastasis and recurrence,which also pose resistances to reactive oxygen species(ROS)-based anti-tumor.Herein,we propos...Post-transcriptional epigenetic modifications provide numerous implications for tumor progression,metastasis and recurrence,which also pose resistances to reactive oxygen species(ROS)-based anti-tumor.Herein,we proposed an epigenetic deubiquitination disruption strategy to disarm the ubiquitination-deubiquitination balance-induced resistances to ROS production and ROS-based anti-tumor action for potentiating sonodynamic treatment(SDT)efficiency.To end it,porphyrin-derived metal-organic framework(MOF)sonocatalytic nanoplatforms were developed to load deubiquitination inhibitors(i.e.,Auranofin).Ultrasound-triggered Auranofin release from PCN224@Au has been validated to blockade the deubiquitinating process and drive proteasome-mediated target protein degradation.The epigenetic deubiquitination disruption not only synergized with MOF-mediated sonocatalytic ROS production,but also inactivate deubiquitinating enzymes,blockade the deubiquitination process and further remove these resistances,both of which mutually behaved as reciprocal impetuses to significantly magnify SDT outcomes against liver cancers.Such a deubiquitination-engineered disruption approach finds an unprecedented pathway to disarm deubiquitination-induced resistances to SDT and other ROS-based anti-tumor means,which also enlightens us to establish other post-transcriptional epigenetic modification disruption strategies to re-program the tumor microenvironment and elevate the anti-tumor efficiency of various treatment methods(e.g.,immunotherapy).展开更多
Atherosclerosis is a chronic artery disease that causes various types of cardiovascular dysfunction.Vascular smooth muscle cells(VSMCs),the main components of atherosclerotic plaque,switch from contractile to syntheti...Atherosclerosis is a chronic artery disease that causes various types of cardiovascular dysfunction.Vascular smooth muscle cells(VSMCs),the main components of atherosclerotic plaque,switch from contractile to synthetic phenotypes during atherogenesis.Ubiquitylation is crucial in regulating VSMC phenotypes in atherosclerosis,and it can be reversely regulated by deubiquitinases.However,the specific effects of deubiquitinases on atherosclerosis have not been thoroughly elucidated.In this study,RNAi screening in human aortic smooth muscle cells was performed to explore the effects of OTU family deubiquitinases,which revealed that silencing OTUB1 inhibited PDGF-BB-stimulated VSMC phenotype switch.Further in vivo studies using Apoe−/−mice revealed that knockdown of OTUB1 in VSMCs alleviated atherosclerosis plaque burden in the advanced stage and led to a stable plaque phenotype.Moreover,VSMC proliferation and migration upon PDGF-BB stimulation could be inhibited by silencing OTUB1 in vitro.Unbiased RNA-sequencing data indicated that knocking down OTUB1 influenced VSMC differentiation,adhesion,and proliferation.Mass spectrometry of ubiquitinated protein confirmed that proteins related to cell growth and migration were differentially ubiquitylated.Mechanistically,we found that OTUB1 recognized the K707 residue ubiquitylation of PDGFRβwith its catalytic triad,thereby reducing the K48-linked ubiquitylation of PDGFRβ.Inhibiting OTUB1 in VSMCs could promote PDGFRβdegradation via the ubiquitin–proteasome pathway,so it was beneficial in preventing VSMCs’phenotype switch.These findings revealed that knocking down OTUB1 ameliorated VSMCs’phenotype switch and atherosclerosis progression,indicating that OTUB1 could be a valuable translational therapeutic target in the future.展开更多
F-box proteins play essential roles in various cellular processes of spermatogenesis by means of ubiquitylation and subsequent target protein degradation.They are the substrate-recognition subunits of SKP1–cullin 1–...F-box proteins play essential roles in various cellular processes of spermatogenesis by means of ubiquitylation and subsequent target protein degradation.They are the substrate-recognition subunits of SKP1–cullin 1–F-box protein(SCF)E3 ligase complexes.Dysregulation of F-box protein-mediated proteolysis could lead to male infertil-ity in humans and mice.The emerging studies revealed the physiological function,pathological evidence,and bio-chemical substrates of F-box proteins in the development of male germ cells,which urging us to review the current understanding of how F-box proteins contribute to spermatogenesis.More functional and mechanistic study will be helpful to define the roles of F-box protein in spermatogenesis,which will pave the way for the logical design of F-box protein-targeted diagnosis and therapies for male infertility,as the spermatogenic role of many F-box proteins remains elusive.展开更多
The obstruction of post-insulin receptor signaling is the main mechanism of insulin-resistant diabetes.Progestin and adipoQ receptor 3(PAQR3),a key regulator of inflammation and metabolism,can negatively regulate the ...The obstruction of post-insulin receptor signaling is the main mechanism of insulin-resistant diabetes.Progestin and adipoQ receptor 3(PAQR3),a key regulator of inflammation and metabolism,can negatively regulate the PI3 K/AKT signaling pathway.Here,we report that gentiopicroside(GPS),the main bioactive secoiridoid glycoside of Gentiana manshurica Kitagawa,decreased lipid synthesis and increased glucose utilization in palmitic acid(PA) treated HepG2 cells.Additionally,GPS improved glycolipid metabolism in streptozotocin(STZ) treated high-fat diet(HFD)-induced diabetic mice.Our findings revealed that GPS promoted the activation of the PI3 K/AKT axis by facilitating DNA-binding protein 2(DDB2)-mediated PAQR3 ubiquitinated degradation.Moreover,results of surface plasmon resonance(SPR),microscale thermophoresis(MST) and thermal shift assay(TSA) indicated that GPS directly binds to PAQR3.Results of molecular docking and cellular thermal shift assay(CETSA) revealed that GPS directly bound to the amino acids of the PAQR3 NH2-terminus including Leu40,Asp42,Glu69,Tyr125 and Ser129,and spatially inhibited the interaction between PAQR3 and the PI3 K catalytic subunit(P110α) to restore the PI3 K/AKT signaling pathway.In summary,our study identified GPS,which inhibits PAQR3 expression and directly targets PAQR3 to restore insulin signaling pathway,as a potential drug candidate for the treatment of diabetes.展开更多
Background:Maintenance of cancer stem-like cell(CSC)stemness supported by aberrantly regulated cancer cell metabolism is critical for CSC self-renewal and tumor progression.As a key glycolytic enzyme,hexokinase 2(HK2)...Background:Maintenance of cancer stem-like cell(CSC)stemness supported by aberrantly regulated cancer cell metabolism is critical for CSC self-renewal and tumor progression.As a key glycolytic enzyme,hexokinase 2(HK2)plays an instrumental role in aerobic glycolysis and tumor progression.However,whether HK2 directly contribute to CSC stemness maintenance in small cell lung cancer(SCLC)is largely unclear.In this study,we aimed to investgate whether HK2 independent of its glycolytic activity is directly involved in stemness maintenance of CSC in SCLC.Methods:Immunoblotting analyses were conducted to determine the expression of HK2 in SCLC CSCs and their differentiated counterparts.CSC-like properties and tumorigenesis of SCLC cells with or without HK2 depletion or overexpression were examined by sphere formation assay and xenograft mouse model.Immunoprecipitation and mass spectrometry analyses were performed to identify the binding proteins of CD133.The expression levels of CD133-associated and CSC-relevant proteins were evaluated by immunoblotting,immunoprecipitation,immunofluorescence,and immunohistochemistry assay.RNA expression levels of Nanog,POU5F1,Lin28,HK2,Prominin-1 were analyzed through quantitative reverse transcription PCR.Polyubiquitination of CD133 was examined by in vitro or in vivo ubiquitination assay.CD133+cells were sorted by flow cytometry using an anti-CD133 antibody.Results:We demonstrated that HK2 expression was much higher in CSCs of SCLC than in their differentiated counterparts.HK2 depletion inhibited CSC stemness and promoted CSC differentiation.Mechanistically,nonmitochondrial HK2 directly interacted with CD133 and enhanced CD133 expression without affecting CD133 mRNA levels.The interaction of HK2 and CD133 promoted the binding of the deubiquitinase ubiquitin-specific protease 11(USP11)to CD133,thereby inhibiting CD133 polyubiquitylation and degradation.HK2-mediated upregulation of CD133 expression enhanced the expression of cell renewal regulators,SCLC cell stemness,and tumor growth in mice.In addition,HK2 expression was positively correlated with CD133 expression in human SCLC specimens,and their expression levels were associated with poor prognosis of SCLC patients.Conclusions:These results revealed a critical non-metabolic function of HK2 in promotion of cancer cell stemness.Our findings provided new insights into the multifaceted roles of HK2 in tumor development.展开更多
Proteolysis targeting chimeras(PROTACs)are dual-functional hybrid molecules that can selectively recruit an E3 ubiquitin ligase to a target protein to direct the protein into the ubiquitinproteasome system(UPS),thereb...Proteolysis targeting chimeras(PROTACs)are dual-functional hybrid molecules that can selectively recruit an E3 ubiquitin ligase to a target protein to direct the protein into the ubiquitinproteasome system(UPS),thereby selectively reducing the target protein level by the ubiquitinproteasome pathway.Nowadays,small-molecule PROTACs are gaining popularity as tools to desrade pathogenic protein.Herein,we present the first small-molecule PROTACs that can induce the alA-adrenergic receptor(α1 A-AR)degradation,which is also the first small-molecule PROTACs for G proteincoupled receptors(GPCRs)to our knowledge.These degradation inducers were developed through conjugation of knownα1-adrenergic receptors(α1-ARs)inhibitor prazosin and cereblon(CRBN)ligand pomalidomide through the different linkers.The representative compound 9 c is proved to inhibit the proliferation of PC-3 cells and result in tumor growth regression,which highlighted the potential of our study as a new therapeutic strategy for prostate cancer.展开更多
Mutations of epigenetic regulators are pervasive in human tumors.ASXL1 is frequently mutated in myeloid malignancies.We previously found that ASXL1 forms together with BAP1 a complex that can deubiquitinylate mono-ubi...Mutations of epigenetic regulators are pervasive in human tumors.ASXL1 is frequently mutated in myeloid malignancies.We previously found that ASXL1 forms together with BAP1 a complex that can deubiquitinylate mono-ubiquitinylated lysine 119 on histone H2A(H2AK119ub1),a Polycomb repressive mark.However,a complete mechanistic understanding of ASXL1 in transcriptional regulation and tumor suppression remains to be defined.Here,we find that depletion of Asxl1 confers murine 32D cells to IL3-independent growth at least partly due to sustained activation of PI3K/AKT signaling.Consistently,Asxl1 is critical for the transcriptional activation of Pten,a key negative regulator of AKT activity.Then we confirm that Asxl1 is specifically enriched and required for H2AK119 deubiquitylation at the Pten promoter.Interestingly,ASXL1 and PTEN expression levels are positively correlated in human blood cells and ASXL1 mutations are associated with lower expression levels of PTEN in human myeloid malignancies.Furthermore,malignant cells with ASXL1 downregulation or mutations exhibit higher sensitivity to the AKT inhibitor MK2206.Collectively,this study has linked the PTEN/AKT signaling axis to deregulated epigenetic changes in myeloid malignancies.It also provides a rationale for mechanism-based therapy for patients with ASXL1 mutations.展开更多
基金Supported by Special Projects in Key Areas for Guangdong Provincial Colleges and Universities (No.2021ZDZX2009)Guangzhou Medical University Discipline Construction Funds (Basic Medicine)(No.JCXKJS2022A05)。
文摘UBE2O is a distinctive ubiquitin-conjugating enzyme characterized by its large size(1292 residues)and dual E2/E3 enzymatic activities,enabling diverse ubiquitylation types.Unlike typical E2 enzymes(150~200 residues),UBE2O’s multifunctionality allows it to regulate substrate degradation,subcellular localization,and functional modulation.Emerging studies highlight its critical roles in protein quality control,erythroid differentiation,metabolic regulation,and maintenance of circadian rhythm.Dysregulation of UBE2O is implicated in various diseases,including cancers,neurodegenerative disorders,and metabolic diseases.This review extensively discusses the unique structural features,diverse biological functions,and pathological roles of UBE2O,as well as its therapeutic potential for associated diseases.
基金supported by the National Natural Science Foundation of China(Nos.82474164,82374124,82073914,82173874,82274185,82305046 and 82304902)the Natural Science Foundation of Jiangsu Province(Nos.BK20230458 and BK20220467)+1 种基金the General Project of the Natural Science Research of Jiangsu Higher Education Institutions(No.23KJB310017)Young Elite Scientists Sponsorship Program by CACM(No.2022-QNRC2-B15).
文摘Developing and identifying effective medications and targets for treating hepatic fibrosis is an urgent priority.Our previous research demonstrated the efficacy of artesunate(ART)in alleviating liver fibrosis by eliminating activated hepatic stellate cells(HSCs).However,the underlying mechanism remains unclear despite these findings.Notably,endocytic adaptor protein(NUMB)has significant implications for treating hepatic diseases,but current research primarily focuses on liver regeneration and hepatocellular carcinoma.The precise function of NUMB in liver fibrosis,particularly its ability to regulate HSCs,requires further investigation.This study aims to elucidate the role of NUMB in the anti-hepatic fibrosis action of ART in HSCs.We observed that the expression level of NUMB significantly decreased in activated HSCs compared to quiescent HSCs,exhibiting a negative correlation with the progression of liver fibrosis.Additionally,ART induced senescence in activated HSCs through the NUMB/P53 tumor suppressor(P53)axis.We identified NUMB as a crucial regulator of senescence in activated HSCs and as a mediator of ART in determining cell fate.This research examines the specific target of ART in eliminating activated HSCs,providing both theoretical and experimental evidence for the treatment of liver fibrosis.
基金supported by the National Key R&D Program of China(Grant No.2016YFD0101003)the “Strategic Priority Research Program” of the Chinese Academy of Sciences(Grant No.XDA08010206)the Agricultural Science and Technology Innovation Program of Jilin Province “Discovery of excellent germplasms and cultivation of inbred lines suitable for mechanized harvesting in maize”(Grant No.CXGC2017JQ019).
文摘The ubiquitin system is crucial for the development and fitness of higher plants.De-etiolation, during which green plants initiate photomorphogenesis and establish autotrophy, is a dramatic and complicated process that is tightly regulated by a massive number of ubiquitylation/de-ubiquitylation events. Here we present site-specific quantitative proteomic data for the ubiquitylomes of de-etiolating seedling leaves of Zea mays L.(exposed to light for 1, 6, or 12 h)achieved through immunoprecipitation-based high-resolution mass spectrometry(MS). Through the integrated analysis of multiple ubiquitylomes, we identified and quantified 1926 unique ubiquitylation sites corresponding to 1053 proteins. We analyzed these sites and found five potential ubiquitylation motifs, KA, AXK, KXG, AK, and TK. Time-course studies revealed that the ubiquitylation levels of 214 sites corresponding to 173 proteins were highly correlated across two replicate MS experiments, and significant alterations in the ubiquitylation levels of 78 sites(fold change >1.5) were detected after de-etiolation for 12 h. The majority of the ubiquitylated sites we identified corresponded to substrates involved in protein and DNA metabolism, such as ribosomes and histones.Meanwhile, multiple ubiquitylation sites were detected in proteins whose functions reflect the major physiological changes that occur during plant de-etiolation, such as hormone synthesis/signaling proteins, key C4 photosynthetic enzymes, and light signaling proteins. This study on the ubiquitylome of the maize seedling leaf is the first attempt ever to study the ubiquitylome of a C4 plant and provides the proteomic basis for elucidating the role of ubiquitylation during plant de-etiolation.
基金supported by Faculty Development Fund and Seed Funding for Applied Research to MSYH(No.201007160001).
文摘Histone ubiquitylation has emerged as an important chromatin modification associated with DNA damage signaling and repair pathways.These histone marks,laid down by E3 ubiquitin ligases that include RNF8 and RNF168,decorate chromatin domains surrounding DNA double-strand breaks(DSBs).Recent work implicated ubiquitylated histones in orchestrating cell cycle checkpoints,DNA repair and gene transcription.Here we summarize recent advances that contribute to our current knowledge of the highly dynamic nature of DSB-associated histone ubiquitylation,and discuss major challenges ahead in understanding the versatility of ubiquitin conjugation in maintaining genome stability.
基金the National Natural Science Foundation of China(Grant No.:81973305)the Science and Technology Planning Project of Guangzhou,China(Grant No.:201904010487)+1 种基金the Natural Science Foundation of Guangdong Province,China(Grant No.:2021A1515010897)the Discipline Construction Fund of Central People’s Hospital of Zhanjiang(Grant Nos.:2020A01 and 2020A02).
文摘Stroke is the second leading cause of death worldwide,and oxidative stress plays a crucial role.Celastrol exhibits strong antioxidant properties in several diseases;however,whether it can affect oxidation in cerebral ischemic-reperfusion injury(CIRI)remains unclear.This study aimed to determine whether celastrol could reduce oxidative damage during CIRI and to elucidate the underlying mechanisms.Here,we found that celastrol attenuated oxidative injury in CIRI by upregulating nuclear factor E2-related factor 2(Nrf2).Using alkynyl-tagged celastrol and liquid chromatography-tandem mass spectrometry,we showed that celastrol directly bound to neuronally expressed developmentally downregulated 4(Nedd4)and then released Nrf2 from Nedd4 in astrocytes.Nedd4 promoted the degradation of Nrf2 through K48-linked ubiquitination and thus contributed to astrocytic reactive oxygen species production in CIRI,which was significantly blocked by celastrol.Furthermore,by inhibiting oxidative stress and astrocyte activation,celastrol effectively rescued neurons from axon damage and apoptosis.Our study uncovered Nedd4 as a direct target of celastrol,and that celastrol exerts an antioxidative effect on astrocytes by inhibiting the interaction between Nedd4 and Nrf2 and reducing Nrf2 degradation in CIRI.
文摘E3 ubiquitin ligases catalyze the final step of ubiquitylation,a crucial post-translational modification involved in almost every process in eukaryotic cells.E3 ubiquitin ligases are key regulators of cellular events,and the investigation into their functions and functioning mechanisms are research areas with great importance.Synthetic or semi-synthetic tools have greatly facilitated the research about the enzyme activity,distribution in different physiological events,and catalytic mechanism of E3 ubiquitin ligase.In this review,we summarize the development of chemical tools for E3 ubiquitin ligases with an emphasis on the synthetic routes.We show the utility of these chemical tools by briefly discussing their applications in biological research.
基金supported by the Excellent Young Scientists Fund of National Natural Science Foundation of China(82022033)National Natural Science Foundation of China(81901753 and 82001820)+3 种基金Shanghai Rising-Star Program(19QA1406800)Shanghai Talent Development Fund(2019040)the Fundamental Research Funds for the Central Universities(22120210561)the program for Shanghai Young Top-Notch Talent.
文摘Post-transcriptional epigenetic modifications provide numerous implications for tumor progression,metastasis and recurrence,which also pose resistances to reactive oxygen species(ROS)-based anti-tumor.Herein,we proposed an epigenetic deubiquitination disruption strategy to disarm the ubiquitination-deubiquitination balance-induced resistances to ROS production and ROS-based anti-tumor action for potentiating sonodynamic treatment(SDT)efficiency.To end it,porphyrin-derived metal-organic framework(MOF)sonocatalytic nanoplatforms were developed to load deubiquitination inhibitors(i.e.,Auranofin).Ultrasound-triggered Auranofin release from PCN224@Au has been validated to blockade the deubiquitinating process and drive proteasome-mediated target protein degradation.The epigenetic deubiquitination disruption not only synergized with MOF-mediated sonocatalytic ROS production,but also inactivate deubiquitinating enzymes,blockade the deubiquitination process and further remove these resistances,both of which mutually behaved as reciprocal impetuses to significantly magnify SDT outcomes against liver cancers.Such a deubiquitination-engineered disruption approach finds an unprecedented pathway to disarm deubiquitination-induced resistances to SDT and other ROS-based anti-tumor means,which also enlightens us to establish other post-transcriptional epigenetic modification disruption strategies to re-program the tumor microenvironment and elevate the anti-tumor efficiency of various treatment methods(e.g.,immunotherapy).
基金supported by grants from the National Key R&D Program of China(No.2021YFC2500500)the National Natural Science Foundation of China(Nos.T2288101 and 82170342)+1 种基金Shanghai Engineering Research Center of Interventional Medicine(No.19DZ2250300)Shanghai Clinical Research Center for Interventional Medicine(No.19MC1910300).
文摘Atherosclerosis is a chronic artery disease that causes various types of cardiovascular dysfunction.Vascular smooth muscle cells(VSMCs),the main components of atherosclerotic plaque,switch from contractile to synthetic phenotypes during atherogenesis.Ubiquitylation is crucial in regulating VSMC phenotypes in atherosclerosis,and it can be reversely regulated by deubiquitinases.However,the specific effects of deubiquitinases on atherosclerosis have not been thoroughly elucidated.In this study,RNAi screening in human aortic smooth muscle cells was performed to explore the effects of OTU family deubiquitinases,which revealed that silencing OTUB1 inhibited PDGF-BB-stimulated VSMC phenotype switch.Further in vivo studies using Apoe−/−mice revealed that knockdown of OTUB1 in VSMCs alleviated atherosclerosis plaque burden in the advanced stage and led to a stable plaque phenotype.Moreover,VSMC proliferation and migration upon PDGF-BB stimulation could be inhibited by silencing OTUB1 in vitro.Unbiased RNA-sequencing data indicated that knocking down OTUB1 influenced VSMC differentiation,adhesion,and proliferation.Mass spectrometry of ubiquitinated protein confirmed that proteins related to cell growth and migration were differentially ubiquitylated.Mechanistically,we found that OTUB1 recognized the K707 residue ubiquitylation of PDGFRβwith its catalytic triad,thereby reducing the K48-linked ubiquitylation of PDGFRβ.Inhibiting OTUB1 in VSMCs could promote PDGFRβdegradation via the ubiquitin–proteasome pathway,so it was beneficial in preventing VSMCs’phenotype switch.These findings revealed that knocking down OTUB1 ameliorated VSMCs’phenotype switch and atherosclerosis progression,indicating that OTUB1 could be a valuable translational therapeutic target in the future.
基金National Natural Science Foundation of China(82371627)Open Research Fund of Key Laboratory of Reproductive Medicine of Guangdong Province(2020B121206002902)+1 种基金Natural Science Foundation of Fujian Province(2021J011346)Xiamen Medical and Health Guidance Project(3502Z20244ZD1021).
文摘F-box proteins play essential roles in various cellular processes of spermatogenesis by means of ubiquitylation and subsequent target protein degradation.They are the substrate-recognition subunits of SKP1–cullin 1–F-box protein(SCF)E3 ligase complexes.Dysregulation of F-box protein-mediated proteolysis could lead to male infertil-ity in humans and mice.The emerging studies revealed the physiological function,pathological evidence,and bio-chemical substrates of F-box proteins in the development of male germ cells,which urging us to review the current understanding of how F-box proteins contribute to spermatogenesis.More functional and mechanistic study will be helpful to define the roles of F-box protein in spermatogenesis,which will pave the way for the logical design of F-box protein-targeted diagnosis and therapies for male infertility,as the spermatogenic role of many F-box proteins remains elusive.
基金supported by research grants from the National Natural Science Foundation of China (No.81770816 and 81973375)the Key Project of Natural Science Foundation of Guangdong Province,China (No.2017A030311036)+1 种基金Seed Program of Guangdong Province (No.2017B090903004,China)Guangdong Provincial Key Field and Program Project (No.2020B1111100004,China)。
文摘The obstruction of post-insulin receptor signaling is the main mechanism of insulin-resistant diabetes.Progestin and adipoQ receptor 3(PAQR3),a key regulator of inflammation and metabolism,can negatively regulate the PI3 K/AKT signaling pathway.Here,we report that gentiopicroside(GPS),the main bioactive secoiridoid glycoside of Gentiana manshurica Kitagawa,decreased lipid synthesis and increased glucose utilization in palmitic acid(PA) treated HepG2 cells.Additionally,GPS improved glycolipid metabolism in streptozotocin(STZ) treated high-fat diet(HFD)-induced diabetic mice.Our findings revealed that GPS promoted the activation of the PI3 K/AKT axis by facilitating DNA-binding protein 2(DDB2)-mediated PAQR3 ubiquitinated degradation.Moreover,results of surface plasmon resonance(SPR),microscale thermophoresis(MST) and thermal shift assay(TSA) indicated that GPS directly binds to PAQR3.Results of molecular docking and cellular thermal shift assay(CETSA) revealed that GPS directly bound to the amino acids of the PAQR3 NH2-terminus including Leu40,Asp42,Glu69,Tyr125 and Ser129,and spatially inhibited the interaction between PAQR3 and the PI3 K catalytic subunit(P110α) to restore the PI3 K/AKT signaling pathway.In summary,our study identified GPS,which inhibits PAQR3 expression and directly targets PAQR3 to restore insulin signaling pathway,as a potential drug candidate for the treatment of diabetes.
基金Ministry of Science and Technology of the People’s Republic of China,Grant/Award Number:2020YFA0803300National Natural Science Foundation of China,Grant/Award Numbers:82188102,82030074,82122053,32100574+10 种基金Beijing Municipal Science&Technology Commission,Grant/Award Number:Z191100006619115R&D Program of Beijing Municipal Education commission,Grant/Award Number:KJZD20191002302CAMS Innovation Fund for Medical Science,Grant/Award Numbers:2021-1-I2M-012,2021-I2M-1-067Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences,Grant/Award Number:2021-PT310-001Key-Area Research and Development Program of Guangdong Province,Grant/Award Number:2021B0101420005Sanming Project of Medicine in Shenzhen,Grant/Award Numbers:SZSM201612097,SZSM201812062Aiyou Foundation,Grant/Award Number:KY201701Natural Science Foundation of Shandong Province,Grant/Award Number:ZR2020QH191Zhejiang Natural Science Foundation-Key Project,Grant/Award Number:LD21H160003Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang,Grant/Award Number:2019R01001Zhimin Lu is the Kuancheng Wang Distinguished Chair。
文摘Background:Maintenance of cancer stem-like cell(CSC)stemness supported by aberrantly regulated cancer cell metabolism is critical for CSC self-renewal and tumor progression.As a key glycolytic enzyme,hexokinase 2(HK2)plays an instrumental role in aerobic glycolysis and tumor progression.However,whether HK2 directly contribute to CSC stemness maintenance in small cell lung cancer(SCLC)is largely unclear.In this study,we aimed to investgate whether HK2 independent of its glycolytic activity is directly involved in stemness maintenance of CSC in SCLC.Methods:Immunoblotting analyses were conducted to determine the expression of HK2 in SCLC CSCs and their differentiated counterparts.CSC-like properties and tumorigenesis of SCLC cells with or without HK2 depletion or overexpression were examined by sphere formation assay and xenograft mouse model.Immunoprecipitation and mass spectrometry analyses were performed to identify the binding proteins of CD133.The expression levels of CD133-associated and CSC-relevant proteins were evaluated by immunoblotting,immunoprecipitation,immunofluorescence,and immunohistochemistry assay.RNA expression levels of Nanog,POU5F1,Lin28,HK2,Prominin-1 were analyzed through quantitative reverse transcription PCR.Polyubiquitination of CD133 was examined by in vitro or in vivo ubiquitination assay.CD133+cells were sorted by flow cytometry using an anti-CD133 antibody.Results:We demonstrated that HK2 expression was much higher in CSCs of SCLC than in their differentiated counterparts.HK2 depletion inhibited CSC stemness and promoted CSC differentiation.Mechanistically,nonmitochondrial HK2 directly interacted with CD133 and enhanced CD133 expression without affecting CD133 mRNA levels.The interaction of HK2 and CD133 promoted the binding of the deubiquitinase ubiquitin-specific protease 11(USP11)to CD133,thereby inhibiting CD133 polyubiquitylation and degradation.HK2-mediated upregulation of CD133 expression enhanced the expression of cell renewal regulators,SCLC cell stemness,and tumor growth in mice.In addition,HK2 expression was positively correlated with CD133 expression in human SCLC specimens,and their expression levels were associated with poor prognosis of SCLC patients.Conclusions:These results revealed a critical non-metabolic function of HK2 in promotion of cancer cell stemness.Our findings provided new insights into the multifaceted roles of HK2 in tumor development.
基金supported by grants from the National Natural Science Foundation of China(No.21629201)the Shandong Natural Science Foundation(No.ZR2018ZC0233,China)+3 种基金the Taishan Scholar Program at Shandong Provincethe Qilu/Tang Scholar Program at Shandong Universitythe Major Project of Science and Technology of Shandong Province(No.2015ZDJS04001,China)the Key Research and Development Project of Shandong Province(No.2017CXGC1401,China)
文摘Proteolysis targeting chimeras(PROTACs)are dual-functional hybrid molecules that can selectively recruit an E3 ubiquitin ligase to a target protein to direct the protein into the ubiquitinproteasome system(UPS),thereby selectively reducing the target protein level by the ubiquitinproteasome pathway.Nowadays,small-molecule PROTACs are gaining popularity as tools to desrade pathogenic protein.Herein,we present the first small-molecule PROTACs that can induce the alA-adrenergic receptor(α1 A-AR)degradation,which is also the first small-molecule PROTACs for G proteincoupled receptors(GPCRs)to our knowledge.These degradation inducers were developed through conjugation of knownα1-adrenergic receptors(α1-ARs)inhibitor prazosin and cereblon(CRBN)ligand pomalidomide through the different linkers.The representative compound 9 c is proved to inhibit the proliferation of PC-3 cells and result in tumor growth regression,which highlighted the potential of our study as a new therapeutic strategy for prostate cancer.
基金This work was supported by the National Natural Science Foundation of China(31570774,31701126,and 31900464)Nati onal Key Research and Development Program(2017YFA0504102)+2 种基金Natural Science Foundation of Tianjin Municipal Science and Technology Commission(17JCZDJC352OO and 18JCQNJC82300)Open Grant from the Chinese Academy of Medical Sciences(157-Zk19-02)Talent Excellence Program from Tianjin Medical University and Research Project of Tianjin Education Commission(2018KJ075).
文摘Mutations of epigenetic regulators are pervasive in human tumors.ASXL1 is frequently mutated in myeloid malignancies.We previously found that ASXL1 forms together with BAP1 a complex that can deubiquitinylate mono-ubiquitinylated lysine 119 on histone H2A(H2AK119ub1),a Polycomb repressive mark.However,a complete mechanistic understanding of ASXL1 in transcriptional regulation and tumor suppression remains to be defined.Here,we find that depletion of Asxl1 confers murine 32D cells to IL3-independent growth at least partly due to sustained activation of PI3K/AKT signaling.Consistently,Asxl1 is critical for the transcriptional activation of Pten,a key negative regulator of AKT activity.Then we confirm that Asxl1 is specifically enriched and required for H2AK119 deubiquitylation at the Pten promoter.Interestingly,ASXL1 and PTEN expression levels are positively correlated in human blood cells and ASXL1 mutations are associated with lower expression levels of PTEN in human myeloid malignancies.Furthermore,malignant cells with ASXL1 downregulation or mutations exhibit higher sensitivity to the AKT inhibitor MK2206.Collectively,this study has linked the PTEN/AKT signaling axis to deregulated epigenetic changes in myeloid malignancies.It also provides a rationale for mechanism-based therapy for patients with ASXL1 mutations.
