Activation of the TAK1 signalosome is crucial for mediating the innate immune response to pathogen invasion and is regulated by multiple layers of posttranslational modifications,including ubiquitination,SUMOylation,a...Activation of the TAK1 signalosome is crucial for mediating the innate immune response to pathogen invasion and is regulated by multiple layers of posttranslational modifications,including ubiquitination,SUMOylation,and phosphorylation;however,the underlying molecular mechanism is not fully understood.In this study,TRIM60 negatively regulated the formation and activation of the TAK1 signalosome.Deficiency of TRIM60 in macrophages led to enhanced MAPK and NF-κB activation,accompanied by elevated levels of proinflammatory cytokines but not IFN-I.Immunoprecipitation-mass spectrometry assays identified TAB2 as the target of TRIM60 for SUMOylation rather than ubiquitination,resulting in impaired formation of the TRAF6/TAB2/TAK1 complex and downstream MAPK and NF-κB pathways.The SUMOylation sites of TAB2 mediated by TRIM60 were identified as K329 and K562;substitution of these lysines with arginines abolished the SUMOylation of TAB2.In vivo experiments showed that TRIM60-deficient mice showed an elevated immune response to LPS-induced septic shock and L.monocytogenes infection.Our data reveal that SUMOylation of TAB2 mediated by TRIM60 is a novel mechanism for regulating the innate immune response,potentially paving the way for a new strategy to control antibacterial immune responses.展开更多
基金This study was supported by grants from the Ministry of Science and Technology(National Key Research and Development Program 2016YFA0502203,2016YFA0502201,2019YFA0110201,2019YFA0110203,2018YFE0204500,and 2018YFC1004601)the National Natural Science Foundation of China(91740111,81871232 and 31870881)the 1.3.5 Project of Disciplines of Excellence and National Clinical Research Center for Geriatrics(Z20201001),West China Hospital,Sichuan University.
文摘Activation of the TAK1 signalosome is crucial for mediating the innate immune response to pathogen invasion and is regulated by multiple layers of posttranslational modifications,including ubiquitination,SUMOylation,and phosphorylation;however,the underlying molecular mechanism is not fully understood.In this study,TRIM60 negatively regulated the formation and activation of the TAK1 signalosome.Deficiency of TRIM60 in macrophages led to enhanced MAPK and NF-κB activation,accompanied by elevated levels of proinflammatory cytokines but not IFN-I.Immunoprecipitation-mass spectrometry assays identified TAB2 as the target of TRIM60 for SUMOylation rather than ubiquitination,resulting in impaired formation of the TRAF6/TAB2/TAK1 complex and downstream MAPK and NF-κB pathways.The SUMOylation sites of TAB2 mediated by TRIM60 were identified as K329 and K562;substitution of these lysines with arginines abolished the SUMOylation of TAB2.In vivo experiments showed that TRIM60-deficient mice showed an elevated immune response to LPS-induced septic shock and L.monocytogenes infection.Our data reveal that SUMOylation of TAB2 mediated by TRIM60 is a novel mechanism for regulating the innate immune response,potentially paving the way for a new strategy to control antibacterial immune responses.
