泛素化是体内蛋白质翻译后重要修饰之一,是蛋白质降解的信号.泛素连接酶E3是泛素化过程中的关键酶之一,介导活化的泛素从结合酶E2转移到底物,不同的泛素连接酶作用于不同的底物蛋白,决定了泛素化修饰的特异性.根据结构与功能机制的不同...泛素化是体内蛋白质翻译后重要修饰之一,是蛋白质降解的信号.泛素连接酶E3是泛素化过程中的关键酶之一,介导活化的泛素从结合酶E2转移到底物,不同的泛素连接酶作用于不同的底物蛋白,决定了泛素化修饰的特异性.根据结构与功能机制的不同,可将泛素连接酶E3分为HECT(homologous to E6AP C terminus)家族和RING-finger家族,前者含有HECT结构域,可直接与泛素连接再将其传递给底物.RING-finger家族的E3发现较晚,庞大且功能复杂,是近年来研究的热点,此家族均包含相似的E2结合结构域和特异的底物结合部分,作为桥梁将活化的泛素从E2直接转移到靶蛋白,其本身并不与泛素发生作用.总结了这2种E3连接酶家族成员的三维结构及功能机制研究的最新进展.展开更多
采用SMART(switching mechanismat 5 end of RNA transcript)技术构建了黑斑蛙(Rana nigromaculata)精巢组织全长cDNA文库。一步法提取成体蛙精巢组织总RNA,用PowerscriptTM反转录酶逆转录合成第一链cD-NA;再用LD-PCR合成双链cDNA;经过...采用SMART(switching mechanismat 5 end of RNA transcript)技术构建了黑斑蛙(Rana nigromaculata)精巢组织全长cDNA文库。一步法提取成体蛙精巢组织总RNA,用PowerscriptTM反转录酶逆转录合成第一链cD-NA;再用LD-PCR合成双链cDNA;经过SfiⅠ酶切和Chroma spin-400柱分离后,500bp以上的片段与λTriplEx2载体连接,再用GigapackⅢGold Packaging Extract包装蛋白包装,即获得原始文库。原始文库进行扩增后得到扩增文库。经检测原始文库的滴度分别为2.0×106pfu/mL和2.4×106pfu/mL,扩增后的文库滴度分别为0.48×109pfu/mL和3.0×109pfu/mL,重组率均在90%以上。通过E.coliBM25.8菌株将文库转化为pTriplEx2质粒,挑选一阳性克隆进行PCR检测,其插入片段平均长度约为1.0kb。挑取一阳性克隆分别从5′端和3′端进行测序,得到一长约1171bp的序列。经序列分析知,该序列含有完整的编码框,可编码305个氨基酸,是一全长cDNA序列。提示所建文库是可以用于全长cDNA的筛选。结果表明,所构建的黑斑蛙精巢组织cDNA文库的各项指标均满足建库的基本要求。该文库将为蛙类及两栖类的已知或未知的功能基因及新基因的获得及其研究提供可靠资源;另外,该文库还将为研究蛙类动物的性别决定和分化相关基因及其表达提供直接的分子资料。展开更多
Inflammasomes are multi-protein complexes that regulate the innate immune response by facilitating the release of inflammatory cytokines in response to pathogen exposure or cellular damage. Pro-inflammatory inflammaso...Inflammasomes are multi-protein complexes that regulate the innate immune response by facilitating the release of inflammatory cytokines in response to pathogen exposure or cellular damage. Pro-inflammatory inflammasome signaling is vital to host defense and helps initiate the process of tissue repair following an insult to the host, but can be injurious, when excessive or chronic. As such, inflammasome activity is tightly regulated. Here we discuss one critical mechanism of inflammasome regulation, ubiquitination, that functions as a universal modulator of protein stability and trafficking. Recent studies have provided important insights into the regulation of inflammasome activation by protein ubiquitination. We review the molecular regulation of inflammasome function, specifically, as it relates to ubiquitination, and discuss the implications for the development of theraoeutics to soecificallv target aberrant inflammasome signaling.展开更多
The Rictor/mTOR complex plays a pivotal role in a variety of cellular functions including cellular metabolism,cell proliferation and survival by phosphorylating Akt at Ser473 to fully activate the Akt kinase.However,i...The Rictor/mTOR complex plays a pivotal role in a variety of cellular functions including cellular metabolism,cell proliferation and survival by phosphorylating Akt at Ser473 to fully activate the Akt kinase.However,its upstream regulatory pathways as well as whether it has additional function(s)remain largely unknown.We recently reported that Rictor contains a novel ubiquitin E3 ligase activity by forming a novel complex with Cullin-1,but not with other Cullin family members.Furthermore,we identified SGK1 as its downstream target.Interestingly,Rictor,but not Raptor or mTOR,promotes SGK1 ubiquitination.As a result,SGK1 expression is elevated in Rictor^(–/–)MEFs.We further defined that as a feedback mechanism,Rictor can be phosphorylated by multiple AGC family kinases including Akt,S6K and SGK1.Phosphorylation of Rictor at the Thr1135 site did not affect its kinase activity towards phosphorylating its conventional substrates including Akt and SGK1.On the other hand,it disrupted the interaction between Rictor and Cullin-1.Consequently,T1135E Rictor was defective in promoting SGK1 ubiquitination and destruction.This finding further expands our knowledge of Rictor’s function.Furthermore,our work also illustrates that Rictor E3 ligase activity could be governed by specific signaling kinase cascades,and that misregulation of this process might contribute to SGK overexpression which is frequently observed in various types of cancers.展开更多
The Tribbles(TRIB) family of pseudokinase proteins has been shown to play key roles in cell cycle, metabolic diseases, chronic inflammatory disease, and cancer development. A better understanding of the mechanisms of ...The Tribbles(TRIB) family of pseudokinase proteins has been shown to play key roles in cell cycle, metabolic diseases, chronic inflammatory disease, and cancer development. A better understanding of the mechanisms of TRIB pseudokinases could provide new insights for disease development and help promote TRIB proteins as novel therapeutic targets for drug discovery. At the 2 nd International Symposium on Tribbles and Diseases held on May 7–9, 2018 in Beijing, China, a group of leading Tribbles scientists reported their findings and ongoing studies about the effects of the different TRIB proteins in the areas of immunity, metabolism, fundamental cell biology and cancer. Here, we summarize important and insightful overviews from 4 keynote lectures, 13 plenary lectures and 8 short talks that took place during this meeting. These findings may offer new insights for the understanding of the roles of TRIB pseudokinases in the development of various diseases.展开更多
文摘泛素化是体内蛋白质翻译后重要修饰之一,是蛋白质降解的信号.泛素连接酶E3是泛素化过程中的关键酶之一,介导活化的泛素从结合酶E2转移到底物,不同的泛素连接酶作用于不同的底物蛋白,决定了泛素化修饰的特异性.根据结构与功能机制的不同,可将泛素连接酶E3分为HECT(homologous to E6AP C terminus)家族和RING-finger家族,前者含有HECT结构域,可直接与泛素连接再将其传递给底物.RING-finger家族的E3发现较晚,庞大且功能复杂,是近年来研究的热点,此家族均包含相似的E2结合结构域和特异的底物结合部分,作为桥梁将活化的泛素从E2直接转移到靶蛋白,其本身并不与泛素发生作用.总结了这2种E3连接酶家族成员的三维结构及功能机制研究的最新进展.
文摘Inflammasomes are multi-protein complexes that regulate the innate immune response by facilitating the release of inflammatory cytokines in response to pathogen exposure or cellular damage. Pro-inflammatory inflammasome signaling is vital to host defense and helps initiate the process of tissue repair following an insult to the host, but can be injurious, when excessive or chronic. As such, inflammasome activity is tightly regulated. Here we discuss one critical mechanism of inflammasome regulation, ubiquitination, that functions as a universal modulator of protein stability and trafficking. Recent studies have provided important insights into the regulation of inflammasome activation by protein ubiquitination. We review the molecular regulation of inflammasome function, specifically, as it relates to ubiquitination, and discuss the implications for the development of theraoeutics to soecificallv target aberrant inflammasome signaling.
基金supported in part by the DOD Prostate New Investigator award to W.W.NIH grant GM089763 to W.W.
文摘The Rictor/mTOR complex plays a pivotal role in a variety of cellular functions including cellular metabolism,cell proliferation and survival by phosphorylating Akt at Ser473 to fully activate the Akt kinase.However,its upstream regulatory pathways as well as whether it has additional function(s)remain largely unknown.We recently reported that Rictor contains a novel ubiquitin E3 ligase activity by forming a novel complex with Cullin-1,but not with other Cullin family members.Furthermore,we identified SGK1 as its downstream target.Interestingly,Rictor,but not Raptor or mTOR,promotes SGK1 ubiquitination.As a result,SGK1 expression is elevated in Rictor^(–/–)MEFs.We further defined that as a feedback mechanism,Rictor can be phosphorylated by multiple AGC family kinases including Akt,S6K and SGK1.Phosphorylation of Rictor at the Thr1135 site did not affect its kinase activity towards phosphorylating its conventional substrates including Akt and SGK1.On the other hand,it disrupted the interaction between Rictor and Cullin-1.Consequently,T1135E Rictor was defective in promoting SGK1 ubiquitination and destruction.This finding further expands our knowledge of Rictor’s function.Furthermore,our work also illustrates that Rictor E3 ligase activity could be governed by specific signaling kinase cascades,and that misregulation of this process might contribute to SGK overexpression which is frequently observed in various types of cancers.
基金supported by National Key R&D Program of China(Grant No.2017YFA0205400,China)the National Natural Science Foundation of China(Grant Nos.81530093 and 81773781,China)+43 种基金Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(Grant No.2016-I2M-1-007,China)CAMS Central Public-interest Scientific Institution Basic Research Fund(Grant No.2017PT3104,China)supported by grants of the National Natural Science Foundation of China(Grant No.81874316,China)the CAMS Innovation Fund for Medical Sciences(Grant No.2016-I2M-3-008,China)supported by grants of from the BBSRC and NWCR(Grant Nos.1088 and 1097,UK)supported by grants of NSF(Grant No.IOS-1456023,USA)NIH(Grant No.NIH R21 CA197317,USA)supported by grants of Ministry of Education,Singapore(Grant Nos.MOE2014-T2-1-012 and 2012-T1-001-036,Singapore)supported by grants from the Health Research Council of New Zealandsupported by a Rutherford Discovery Fellowship from the New Zealand government administered by the Royal Society of New Zealandsupported by Funda??o para a Ciência e a Tecnologia(FCT)Research Center Grant UID/BIM/04773/2013 Centre for Biomedical Research 1334a research grant from Liga Portuguesa Contra o Cancro–Núcleo Regional do Sul(LPCC/NRS,Portugal)a FCT 2014 research grant SFRH/BPD/100434/2014a Pro Regem grant PD/BD/114258/2016(Portugal)supported by European Marie Sklodowska Curie ITN Project TRAIN-TRIBBLES Research and Innovation Network(Grant No.721532,EU)Innovation Network and the British Heart Foundation(PG/16/44/32146,UK)supported by grants from The Howat Foundation Ltd.(UK),Children with Cancer UK,Bloodwise and the Friends of Paul O'Gorman(UK)supported by grants of P-CREATE from Japan Agency for Medical Research and Developmentsupported by grants from the NIH(NIAID,USA),Alex's Lemonade Stand Foundation(USA)and the Samuel Waxman Cancer Research Foundation(USA)supported by European Marie Sklodowska Curie ITN Project TRAIN-TRIBBLES Research and Innovation Network(Grant No.721532,EU)the "Fondation Centaure"(RTRS),which supports a French transplantation research network,the IHU-Cesti project,the DHU Oncogreffefinancial support managed by the National Research Agency via the"Investment into the Future" program(Grant Nos.ANR-10-IBHU-005and ANR-11-LABX-0016-01,France)supported by Nantes Métropole and Région Pays de la Loire(France)supported by grants of the British Heart Foundation(PG/16/44/32146,UK)supported by European Marie Sklodowska Curie ITN Project TRAIN-TRIBBLES Research and Innovation Network(Grant No.721532,EU)supported by European Marie Sklodowska Curie ITN Project TRAIN-TRIBBLES Research and Innovation Network(Grant No.721532,EU)supported by a joint Ph.D studentship beween the A*Star Institute and the University of Sheffield(UK)supported by funding from the National Institutes of Health National Heart,Lung,and Blood Institute(R01HL141745,USA)supported by European Marie Sklodowska Curie ITN Project TRAIN-TRIBBLES Research and Innovation Network(Grant No.721532,EU)supported by European Marie Sklodowska Curie ITNProject TRAIN-TRIBBLES Research and Innovation Network(Grant No.721532,EU)supported by the National Natural Science Foundation of China(Grant No.81503128,China)CAMS Innovation Fund for Medical Sciences(Grant No.2016-I2M-1-008,China)supported by National Institute of Health(NS R01-035546,USA)supported by the National Natural Science Foundation of China(Grant No.81400140,China)CAMS Innovation Fund for Medical Sciences(Grant No.2016-I2M-1-011,China)supported by European Marie Sklodowska Curie ITN Project TRAIN-TRIBBLES Research and Innovation Network(Grant No.721532,EU)supported by Spanish Ministry of Economy and Competitiveness(MINECO)and Fondo Europeo de desarrollo Regional(FEDER)(Grant No.INNPACTO/IPT-2012-0614-010000,Spain)supported by the National Natural Science Foundation of China(Grant Nos.81400286 and 81530093,China)the CAMS Innovation Fund for Medical Sciences(Grant No.2016-I2M-1-010,China)supported by the National Natural Science Foundation of China(Grant Nos.81472717 and 81673474,China)Beijing Natural Science Foundation(Grant No.7162133,China)the CAMS Innovation Fund for Medical Sciences(Grant No.2016-I2M-1-007,China)supported by the National Natural Science Foundation of China(Grant No.81703564,China)supported by the National Natural Science Foundation of China(Grant No.81603129,China)
文摘The Tribbles(TRIB) family of pseudokinase proteins has been shown to play key roles in cell cycle, metabolic diseases, chronic inflammatory disease, and cancer development. A better understanding of the mechanisms of TRIB pseudokinases could provide new insights for disease development and help promote TRIB proteins as novel therapeutic targets for drug discovery. At the 2 nd International Symposium on Tribbles and Diseases held on May 7–9, 2018 in Beijing, China, a group of leading Tribbles scientists reported their findings and ongoing studies about the effects of the different TRIB proteins in the areas of immunity, metabolism, fundamental cell biology and cancer. Here, we summarize important and insightful overviews from 4 keynote lectures, 13 plenary lectures and 8 short talks that took place during this meeting. These findings may offer new insights for the understanding of the roles of TRIB pseudokinases in the development of various diseases.
