Molecular mechanism of dimeric G protein-coupled receptor signaling

二聚体G蛋白偶联受体信号传导的分子机制

基本信息

批准号：
10582139
负责人：
QING R FAN
金额：
$ 4.42万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-04-02 至 2026-03-31
项目状态：
未结题

项目摘要

Summary Our research seeks to uncover the molecular mechanisms of activation and modulation of two dimeric G protein-coupled receptors (GPCRs), human GABAB receptor and human calcium-sensing (CaS) receptor. The GABAB receptor is ubiquitous in the central nervous system, responsible for mediating slow and prolonged synaptic inhibition. Defects in GABAB receptor have been implicated in brain and behavioral disorders, including spasticity, epilepsy, addiction, and anxiety. CaS receptor maintains a stable Ca2+ level in the blood. Abnormal activities of the CaS receptor are associated with a vareity of Ca2+ homeostatic disorders including potentially life threatening hypercalcemic conditions. Both receptors function as obligatory dimers and contain large extracellular domains that are responsible for orthosteric ligand binding. Fundamental questions remain regarding how an extracellular stimulus propagates a signal across the membrane through such a dimeric GPCR system. Building on our structural models for the extracellular domains of each receptor, we plan to determine full-length structures of these GPCRs, including their transmembrane domains, in multiple functional states. For each receptor, we aim to address three main questions: (1) how the dimeric interactions control receptor activation, (2) what the mode of coupling between each receptor and its cognitive G protein is, and (3) how allosteric modulators and auxiliary proteins regulate receptor function. We will combine structural and functional approaches to understand the molecular basis of ligand-induced activation in each receptor system. Our findings will ultimately lead to the development of novel therapeutics for treating diseases associated with the GABAB and CaS receptors.

概括我们的研究旨在揭示两种物质激活和调节的分子机制二聚体 G 蛋白偶联受体 (GPCR)、人类 GABAB 受体和人类钙感应 (CaS) 受体。 GABAB 受体普遍存在于中枢神经系统中，负责介导缓慢且长时间的突触抑制。 GABAB 受体缺陷与大脑和行为障碍，包括痉挛、癫痫、成瘾和焦虑。 CaS受体维持血液中稳定的Ca2+水平。 CaS 受体的异常活性与多种 Ca2+ 稳态紊乱，包括可能危及生命的高钙血症。两种受体均作为必需二聚体发挥作用，并含有大的细胞外结构域负责正位配体结合。关于如何细胞外刺激通过这种二聚体 GPCR 系统跨膜传播信号。基于每个受体胞外域的结构模型，我们计划确定这些 GPCR 的全长结构，包括其跨膜结构域，具有多种功能州。对于每个受体，我们的目标是解决三个主要问题：（1）二聚体如何相互作用控制受体激活，（2）每个受体与其认知G之间的耦合模式是什么 (3)变构调节剂和辅助蛋白如何调节受体功能。我们将结合结构和功能方法来了解配体诱导的分子基础每个受体系统的激活。我们的发现最终将导致新颖的开发用于治疗与 GABAB 和 CaS 受体相关的疾病的疗法。