Mechanism of activation and modulation in human GABA(B) receptor

人 GABA(B) 受体的激活和调节机制

基本信息

批准号：
10224896
负责人：
QING R FAN
金额：
$ 42.18万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-01 至 2022-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10224896
关键词：
Address Adenylate Cyclase Affect Affinity Agonist Anxiety Baculoviruses Behavioral Binding Binding Proteins Biological Assay Brain Brain Diseases Cell Surface Receptors Cell surface Cells Communication Complex Coupling Cryoelectron Microscopy Crystallization Data Defect Development Disease Electron Microscopy Epilepsy Extracellular Domain Family G-Protein-Coupled Receptors GABA-B Receptor GTP-Binding Protein alpha Subunits, Gs GTP-Binding Proteins Goals Homo Human Insecta Kinetics Length Ligand Binding Ligands Light Measures Mediating Modeling Molecular Molecular Conformation Molecular Structure Mood Disorders Mutation Neurotransmitters Peptides Potassium Channel Property Proteins Receptor Activation Receptor Signaling Regulation Rest Side Signal Transduction Structural Models Structure Therapeutic Agents Transmembrane Domain X-Ray Crystallography addiction base brain behavior desensitization design dimer experimental study extracellular gamma-Aminobutyric Acid human disease innovation member molecular mass nanodisk nervous system disorder neurotransmission novel therapeutics radioligand receptor receptor function reconstitution scaffold spasticity synaptic inhibition

项目摘要

PROJECT SUMMARY The inhibitory neurotransmitter GABA produces slow and prolonged inhibition in the brain through activation of metabotropic GABAB receptors (GABABR). Defects in GABABR signaling have been implicated in various neurological and mood disorders including spasticity, epilepsy, addiction and anxiety. GABABR is a member of the class C G protein-coupled receptor (GPCR) family, which typically functions as a dimer and possesses large extracellular domains. Fundamental questions remain concerning the molecular mechanisms underlying activation and modulation of these class C receptors. The GABABR is a heterodimer of GABAB1 and GABAB2 subunits and is modulated by the potassium channel tetramerization domain-containing (KCTD) protein auxiliary subunits. In this proposal, we will develop structural models for full-length GABABR, its auxiliary subunits and their complexes with G- protein. Building on our structural models for both the extracellular and intracellular components of human GABABR, we propose to determine the structural diversity of GABABR auxiliary subunits KCTDs, and elucidate the interactions between KCTDs and G proteins (Aim 1), describe the molecular association between GABABR and KCTD, and determine its impact on GABABR signaling (Aim 2), and solve the structures of full-length GABABR in multiple functional states, characterizing the allosteric interaction between the GABABR and G proteins (Aim 3). We will use an innovative strategy of combining structural and functional analyses, including cryo-electron microscopy (EM) and nanodiscs. Together, these studies will advance our understanding of the molecular basis of GABA action in the brain, leading to the development of novel therapeutics for treating neurological diseases.

项目概要抑制性神经递质 GABA 通过以下方式在大脑中产生缓慢而持久的抑制：代谢型 GABAB 受体 (GABABR) 的激活。 GABABR 信号传导缺陷与各种神经和情绪障碍有关，包括痉挛、癫痫、成瘾和焦虑。 GABABR 是 C 类 G 蛋白偶联受体 (GPCR) 家族的成员，通常作为二聚体发挥作用并具有大的细胞外结构域。基本问题仍然存在关于这些 C 类受体激活和调节的分子机制。 GABABR 是 GABAB1 和 GABAB2 亚基的异二聚体，受钾离子调节含有通道四聚化结构域 (KCTD) 的蛋白质辅助亚基。在本提案中，我们将开发全长 GABABR、其辅助亚基及其与 G- 的复合物的结构模型蛋白质。以我们的细胞外和细胞内成分的结构模型为基础人类 GABABR，我们建议确定 GABABR 辅助亚基的结构多样性 KCTD，并阐明 KCTD 和 G 蛋白之间的相互作用（目标 1），描述了分子 GABABR 和 KCTD 之间的关联，并确定其对 GABABR 信号传导的影响（目标 2），以及解析全长 GABABR 在多种功能状态下的结构，表征变构 GABABR 和 G 蛋白之间的相互作用（目标 3）。我们将采用创新策略结合结构和功能分析，包括冷冻电子显微镜 (EM) 和纳米圆盘。总之，这些研究将增进我们对 GABA 作用的分子基础的理解。脑，导致治疗神经系统疾病的新疗法的开发。