Sumoylation of PKC and its function in T cell activation

【作者】 龚宇； 龚贝妮； 王旭东； 李士卿； 谢吉佶； 刁梁辉； 李迎秋；

【机构】 中山大学生命科学学院； 中山大学有害生物控制与资源利用国家重点实验室；

【摘要】 <正>Background and purpose:Protein kinase C-θ(PKCθ) plays an essential role in TCR/CD28-induced T cell activation.However,the molecular basis of PKCθactivation and TCR-rich central supramolecular activation cluster(cSMAC) localization remains incompletely understood.We try to discover the novel mechanisms behind.Methods:We employed Ubc9 fusion-directed sumoylation(UFDS) method to analyze if PKC0 can be sumoylated;then we checked sumoylation of endogenous PKCθafter TCR/CD28-stimulation by immunoprecipitation and western blotting;further we used T-B cells conjugation,reporter gene assay,Elisa experiments to demonstrate the physiological function of sumoylation modification of PKCθ.Results:PKCθis constitutively selectively sumoylated by SUMO1 not SUMO2/3 and TCR/CD28 costimulation promoted PKCθsumoylation.A unsumoylated form of PKCθimpairs TCR/CD28-induced signaling pathway and cSMAC translocation,thus less IL-2 production and T cell activation.Conclusion:Sumoylation modification is required for PKCθmaintaining proper function in T cell.Our findings define a novel mechanism underlying TCR/CD28-triggered PKCθactivation and cSMAC localization.更多还原

【Abstract】 Background and purpose:Protein kinase C-θ(PKCθ) plays an essential role in TCR/CD28-induced T cell activation.However,the molecular basis of PKCθactivation and TCR-rich central supramolecular activation cluster(cSMAC) localization remains incompletely understood.We try to discover the novel mechanisms behind.Methods:We employed Ubc9 fusion-directed sumoylation(UFDS) method to analyze if PKC0 can be sumoylated;then we checked sumoylation of endogenous PKCθafter TCR/CD28-stimulation by immunoprecipitation and western blotting;further we used T-B cells conjugation,reporter gene assay,Elisa experiments to demonstrate the physiological function of sumoylation modification of PKCθ.Results:PKCθis constitutively selectively sumoylated by SUMO1 not SUMO2/3 and TCR/CD28 costimulation promoted PKCθsumoylation.A unsumoylated form of PKCθimpairs TCR/CD28-induced signaling pathway and cSMAC translocation,thus less IL-2 production and T cell activation.Conclusion:Sumoylation modification is required for PKCθmaintaining proper function in T cell.Our findings define a novel mechanism underlying TCR/CD28-triggered PKCθactivation and cSMAC localization.更多还原