Gq蛋白耦联受体调控TREK-1通道离子选择器构象变化的机制研究

项目名称： Gq蛋白耦联受体调控TREK-1通道离子选择器构象变化的机制研究

项目编号： No.31200797

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 神经、认识与心理学

项目作者： 马晓芸

作者单位： 中国人民解放军军事医学科学院

项目金额： 27万元

中文摘要： TREK-1为双孔钾离子通道家族成员之一，在调节细胞兴奋性、神经发育、神经保护、痛觉及激素分泌等生理过程中起重要作用。Gq蛋白偶联受体（GqPCR）信号通路对TREK-1的调控为一些激素和神经递质发挥功能所必需，而GqPCR激活后TREK-1通道控制钾离子流出机制未知。钾通道离子选择器构象变化在其控制钾离子流出方面发挥着关键的作用。根据现有文献和我们的前期实验结果，推测GqPCR可能通过改变通道离子选择器的构象来实现其对TREK-1的调控。本研究拟采用细胞电生理技术和点突变技术，探讨TREK-1通道离子选择器构象转换在GqPCR对该通道调控过程中的作用，并弄清TREK-1胞内C末端近侧区是否通过操纵内门活动参与该调控过程。本研究将进一步丰富双孔钾离子通道家族门控机制及离子选择器构象变化机制等方面的内容，为最终阐明GqPCR及其配体系统调控TREK-1通道的分子机制提供新的理论和实验依据。

中文关键词： TREK-1；TREK-2；门控机制；离子选择器；双孔钾通道

英文摘要： TREK-1，a member of two-pore-domain potassium channel (K2P) family，is implicated in physiological process, including regulation of cell excitation, neuroprotection, pain, hormone secretion, etc. The regulation of Gq-protein coupled receptors (GqPCR) to TREK-1 is necessary for some hormones or neurotransmitters to exert their functions, but little is known about the regulation mechanism of potassium ions efflux in TREK-1 channel after the GqPCRs are activated. The conformational transition of the selectivity filter (SF) plays a pivotal role in the gating mechanism of potassium channels. Based on current references and our previous results, we speculate that GqPCRs may regulate TREK-1 by manipulating the conformation of the SF. By using cellular electrophysiological techniques and mutagenesis techniques, we plan to investigate the role of SF transition in the modulation of TREK-1 by GqPCR, and to further clarify the possibility of the involvement of C-terminal proximal region by controlling the inner gate. The conclusions of the study may not only add new contents to the gate mechanism and SF function of K2P family, but also provide new theory and experimental basis to clarify ultimately the molecular mechanism of TREK-1 channel regulated by GqPCRs and their ligands.

英文关键词： TREK-1；TREK-2；gating mechanism；selectivity filter；two-pore-domain potassium channel