Structural Studies of Metabotropic GABA Receptors

代谢型 GABA 受体的结构研究

基本信息

批准号：
8513349
负责人：
QING R FAN
金额：
$ 28.78万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-08-15 至 2016-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8513349
关键词：
Adenylate Cyclase Affect Affinity Agonist Binding Biochemical Biological Assay Brain Cells Coiled-Coil Domain Complex Coupling Crystallography Development Dimerization Disease Epilepsy Extracellular Domain G-Protein-Coupled Receptors GABA Receptor GTP-Binding Proteins Goals Health Heterodimerization Homology Modeling Human Individual Length Ligand Binding Ligands Logistics Measures Mediating Methodology Methods Modeling Molecular Mutagenesis Mutation Pain Potassium Channel Process Receptor Activation Regulation Research Role Signal Transduction Specificity Structural Models Structure Surface System Techniques Therapeutic Agents Work base design gamma-Aminobutyric Acid information model inward rectifier potassium channel mutant nervous system disorder neurotransmission novel therapeutics patch clamp radioligand receptor receptor function trafficking

项目摘要

DESCRIPTION (provided by applicant): Metabotropic GABAB receptors mediate inhibitory neurotransmission in the mammalian brain and are central to its function. GABAB receptors are G-protein coupled receptors (GPCRs) that regulate the activity of Ca2+ and K+ channels, and inhibit the function of adenylyl cyclase. Malfunction of GABAB receptors has been implicated in the development of a number of diseases including spasticity, epilepsy and pain. Therefore, elucidating the structure and function of GABAB receptors would assist the design of valuable therapeutic agents. Unlike most GPCRs, GABAB receptors function as a heterodimeric assembly of GBR1 and GBR2 subunits. Heterodimerization is required for the trans-activation of these receptors, where GBR1 is responsible for ligand-binding and GBR2 is involved in G-protein coupling. The first part of this proposal is aimed at understanding the role of GBR1 and GBR2 ectodomains in the activation process. We propose to solve the structures of the individual subunits and study their interactions using biochemical methods. The second aim is to reveal the structural basis of ligand-binding and dimerization of an ectodomain heterodimer, and determine the affinity and specificity of receptor-ligand interactions. Our third aim is to understand the molecular basis of heterodimerization by the intracellular coiled-coil domains and their role in receptor assembly and trafficking. The last part of the proposed research is focused on understanding transmembrane signal transduction mechanism using full-length receptors. We propose to carry out functional studies of wild-type and mutant receptors using whole cell patch clamp methodology. Mutations that affect ligand binding, receptor heterodimerization, and receptor activation will be designed based on the available structural information and homology models. A combination of structural and functional analysis of GABAB receptors will advance our understanding of the molecular basis of GABA action and the activation mechanisms particular to GPCR heterodimers. PUBLIC HEALTH RELEVANCE: Malfunction of metabotropic GABA receptors leads to neurological disorders in human. We are pursuing structural models for different components of GABA receptors in order to understand their roles in receptor function. The resulting atomic structures may assist the design of novel therapeutic agents.

描述（由申请人提供）：代谢性GABAB受体介导哺乳动物大脑中的抑制性神经传递，并且是其功能的核心。 GABAB受体是调节Ca2+和K+通道活性的G蛋白偶联受体（GPCR），并抑制腺苷酸环化酶的功能。 GABAB受体的故障与多种疾病的发展有关，包括痉挛，癫痫和疼痛。因此，阐明GABAB受体的结构和功能将有助于设计有价值的治疗剂。与大多数GPCR不同，GABAB受体充当GBR1和GBR2亚基的异二聚体组件。这些受体的反式激活需要异二聚化，其中GBR1负责配体结合，而GBR2参与G蛋白偶联。该提案的第一部分旨在了解GBR1和GBR2外生素在激活过程中的作用。我们建议解决各个亚基的结构，并使用生化方法研究它们的相互作用。第二个目的是揭示外生域异二聚体配体结合和二聚化的结构基础，并确定受体配体相互作用的亲和力和特异性。我们的第三个目的是了解细胞内卷曲螺旋域及其在受体组装和运输中的作用的异构化的分子基础。拟议的研究的最后一部分集中在使用全长受体理解跨膜信号转导机制。我们建议使用全细胞贴片夹方法进行野生型和突变受体的功能研究。会根据可用的结构信息和同源性模型设计影响配体结合，受体异构化和受体激活的突变。 GABAB受体的结构和功能分析的结合将提高我们对GABA作用的分子基础以及GPCR异二聚体所特有的激活机制的理解。公共卫生相关性：代谢性GABA受体的故障导致人类神经系统疾病。我们正在为GABA受体的不同组成部分追求结构模型，以了解它们在受体功能中的作用。由此产生的原子结构可以帮助设计新型治疗剂。