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
A full-length cDNA library from the testis of dark-spotted frogs （ Rana nigromaculata ） was constructed with the SMART （switching mechanism at 5＇ end of RNA transcript） technique. Total RNA was extracted from the...A full-length cDNA library from the testis of dark-spotted frogs （ Rana nigromaculata ） was constructed with the SMART （switching mechanism at 5＇ end of RNA transcript） technique. Total RNA was extracted from the testis and reverse transcripted into full-length cDNA using PowerScript reverse transcriptase. The first-strand cDNA was amplified using long-distance PCR （LD-PCR）. After Sfi Ⅰ digestion and fractionation, cDNA （ 〉 500 bp） was ligated to λ TriplEx2 vector and packaged with GigapackⅢ Gold Packaging Extract. The titers of optimal primary libraries were 2.0×10^6 pfu/mL and 2.4 × 10^6 pfu/mL and the tlters of the amplified libraries were 0.48 × 10^9 pfu/mL and 3.0 × 10^9 pfu/ mL, respectively. The percentages of recombinant clones of primary libraries and amplified libraries were all over 90%. The libraries were converted into pTriplEx2 plasmids in E. coli BM 25.8 strain. The insert sizes were measured by PCR which showed most fragments were over 500 bp and the average length was 1.0 kb approximately. A positive clone of 1 171 bp was sequenced and named RnUb based on sequence similarity with the known ubiquitin genes in Gen- Bank. This sequence was a full-length cDNA with complete coding sequences, which indicated that the library built a base for screening the full-length cDNA. These data showed that this library attained to the requirements of a standard cDNA library. This library provided a useful resource for the functional genomic research of Rana nigromaculata.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
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
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
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The National Natural Science Foundation of China(30640048)the Natural Science Foundation in Anhui Province(01043202)
文摘A full-length cDNA library from the testis of dark-spotted frogs （ Rana nigromaculata ） was constructed with the SMART （switching mechanism at 5＇ end of RNA transcript） technique. Total RNA was extracted from the testis and reverse transcripted into full-length cDNA using PowerScript reverse transcriptase. The first-strand cDNA was amplified using long-distance PCR （LD-PCR）. After Sfi Ⅰ digestion and fractionation, cDNA （ 〉 500 bp） was ligated to λ TriplEx2 vector and packaged with GigapackⅢ Gold Packaging Extract. The titers of optimal primary libraries were 2.0×10^6 pfu/mL and 2.4 × 10^6 pfu/mL and the tlters of the amplified libraries were 0.48 × 10^9 pfu/mL and 3.0 × 10^9 pfu/ mL, respectively. The percentages of recombinant clones of primary libraries and amplified libraries were all over 90%. The libraries were converted into pTriplEx2 plasmids in E. coli BM 25.8 strain. The insert sizes were measured by PCR which showed most fragments were over 500 bp and the average length was 1.0 kb approximately. A positive clone of 1 171 bp was sequenced and named RnUb based on sequence similarity with the known ubiquitin genes in Gen- Bank. This sequence was a full-length cDNA with complete coding sequences, which indicated that the library built a base for screening the full-length cDNA. These data showed that this library attained to the requirements of a standard cDNA library. This library provided a useful resource for the functional genomic research of Rana nigromaculata.
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)+20 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),whic
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.
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.
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.
