G蛋白偶联受体介导的蛋白激酶C激活及其下游信号通路的机制研究

GPCRs是细胞表面最大受体家族，也是新药研发最主要的靶标。GPCRs可以通过G蛋白依赖的信号通路激活PKCs以及下游效应分子。PKC是丝/苏氨酸蛋白激酶家族的一员，在大多组织中介导着很多生理和病理过程的调控。但由于研究工具的局限性和抑制剂的不专一性，GPCRs介导PKC不同亚型的激活，以及对下游效应分子的调控及其机制尚待阐明。本项目旨在前期工作基础上，利用已建立的GPCR功能活性检测平台，结合PKC转位检测方法，研究阐明GPCRs通过G蛋白分别激活哪些亚型的PKC及其相应的机制，以及PKC各亚型又是如何激活下游效应分子及其分子机制；还有Gs-GPCRs介导的信号通路可以激活PKCγ入核的分子机制和生理作用。本项目完全是在已有的研究基础上展开的创新研究, 为进一步探索和理解PKCs在GPCRs介导的信号通路以及对生理生化调节中的生理功能，也为以GPCRs为靶点的新药研发提供更好的理论基础。

As the largest family of plasma membrane receptors, G protein-coupled receptors (GPCRs) represent one of the most important therapeutic targets for disease treatment. GPCRs activate protein kinase Cs (PKCs) and subsequent downstream effectors through G proteins-dependent signaling pathways. PKCs constitute a family of phospholipid-dependent serine/threonine kinases, and are involved in diverse intracellular signaling pathways and regulates various cellular functions. However, owing to limited pharmacological tools and non-specific inhibitors, the GPCRs-mediated activation of PKC isozymes and subsequent signaling cascades remain to be further elucidated. Therefore, based on our preliminary studies, in addition to our well established platform of GPCR functional assays, we propose this research project and aim to clarify the roles of Gαq, Gαi/o, Gαs and Gβγ in the activation of different PKC subtypes and mechanisms involved in the PKC isozyme specifically mediated activation of downstream signaling using combination of PKC-GFP translocation assays with different inhibitors such as small molecular inhibitors, peptide inhibitors, siRNA and dominant-negative constructs. We will also focus on the elucidation of the mechanism(s) involved in the Gαs-GPCR-induced nuclear translocation of PKCγ and its possible physiological roles in the control of essential nuclear events. This project is an innovative research, and a better understanding of the functional significance of PKC isozymes in defined cellular signaling processes may provide potential therapeutic strategies and targets for the treatment of diseases.