Structural Basis of Signal Instigation Through Family C GPCRs

通过 C 族 GPCR 激发信号的结构基础

基本信息

批准号：
10767205
负责人：
Georgios Skiniotis
金额：
$ 6.06万
依托单位：
STANFORD UNIVERSITY
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：
2021-03-15 至 2026-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10767205
关键词：
Address Agonist Aminobutyric Acids Binding Binding Proteins Binding Sites Biochemical Biological Assay Cell membrane Central Nervous System Central Nervous System Diseases Communication Complement Complex Coupled Couples Coupling Cryoelectron Microscopy Cysteine-Rich Domain Defect Detergents Disease Drug Addiction Environment Extracellular Domain Family Functional disorder G Protein-Coupled Receptor Signaling G-Protein-Coupled Receptors GRM5 gene GTP-Binding Proteins Glutamate Receptor Glutamates Heterotrimeric GTP-Binding Proteins Knowledge Length Ligand Binding Link Lipids Maps Membrane Mental Depression Metabotropic Glutamate Receptors Micelles Molecular Molecular Conformation Mutagenesis Mutation Nerve Degeneration Neurologic Pain Parkinson Disease Phospholipids Physiological Preparation Property Proteins Protomer Receptor Activation Repression Resolution Role Schizophrenia Side Signal Transduction Site Specificity Structure Synaptic Transmission Synaptic plasticity System Testing Transmembrane Domain Venus Work combat computer studies conformational conversion design dimer drug discovery extracellular fly gamma-Aminobutyric Acid in vitro Assay insight metabotropic glutamate receptor 2 metabotropic glutamate receptor type 1 molecular dynamics nanodisk neuronal excitability neuropsychiatry neurotransmission novel therapeutic intervention pharmacologic protein activation protein complex receptor receptor coupling receptor function release of sequestered calcium ion into cytoplasm structural determinants therapeutic target

项目摘要

Abstract The γ-aminobutyric acid B receptor (GABABR) and the metabotropic glutamate receptors (mGluRs) belong to the Family C of G protein coupled receptors (GPCRs) and critically regulate neuronal excitability, synaptic transmission and plasticity. Many disorders of the CNS have been linked to alterations in neuronal excitability via the glutamatergic and GABAergic system. Accordingly, mGluRs and GABABR have been the subject of an enormous drug discovery effort as they represent major therapeutic targets for treating numerous physiological dysfunctions and for neurodegenerative and neuropsychiatric conditions. Apart from the prototypical seven transmembrane helix (7TM) domain, Family C GPCRs also include a large extracellular ‘venus fly trap’ (VFT) domain that constitutes the orthosteric ligand binding site. Binding of ligand to the extracellular VFT domain triggers a large conformational change in the VFT domains from an open to a closed conformation. This clam- shell like closure of the extracellular domain results in receptor engagement and activation of G proteins on the intracellular side of the transmembrane domain with a mechanism that remains unclear. Receptor activated G proteins then act to either enhance or repress secondary messenger signaling cascades. We recently showed cryoEM structures of near-full length mGluR5 and GABABR in inactive and active conformations, revealing extensive transitions in the organization of the 7TM dimer upon ligand binding to the VFT. Notwithstanding this progress, several key questions remain regarding the allosteric communication across the cell membrane by Family C GPCRs, and particularly the mechanism of G protein coupling and activation. To address these questions, we propose to obtain the structures of mGluR2, mGluR5 and GABABR in complex with their cognate G proteins and probe the structural insights using molecular dynamics simulations and mutagenesis coupled to functional assays. The similarities and differences amongst these receptor-G protein complexes will allow us to contrast and compare our findings and examine aspects of G protein coupling and selectivity. Collectively, these studies will enable us to create a detailed mechanistic framework to understand Family C GPCR signaling and will form the basis for the design of novel therapeutic strategies targeting these receptors.

抽象的 γ-氨基丁酸B受体（GABABR）和代谢型谷氨酸受体（MGLURS）属于 G蛋白耦合受体（GPCR）的C族，并严重调节神经元令人兴奋的突触传输和可塑性。中枢神经系统的许多疾病都与神经元令人兴奋的改变有关通过谷氨酸能和GABA能系统。根据以下内容，mglurs和gababr已成为巨大的药物发现工作代表了用于治疗众多生理的主要治疗靶标功能障碍以及神经退行性和神经精神疾病。除了典型七跨膜螺旋（7TM）结构域，家族C GPCR还包括一个大的细胞外“金星蝇陷阱”（VFT）构成正常配体结合位点的结构域。配体与细胞外VFT结构域的结合从开放到封闭构象中，VFT域中触发了巨大的构象变化。这个蛤 - 壳，例如闭合细胞外域会导致受体的接合和G蛋白激活跨膜结构域的细胞内侧具有不清楚的机制。受体激活的g 然后，蛋白质作用以增强或反映次级信使信号级联。我们最近显示在不活跃和活跃的构象中，接近满length的冷冻结构揭示在配体与VFT结合后，在7tm二聚体的组织中进行了广泛的过渡。尽管如此进展，关于整个细胞膜的变构通信的几个关键问题仍然存在家族C GPCR，尤其是G蛋白偶联和激活的机制。解决这些问题，我们建议获得mglur2，mglur5和gababr的结构与它们的同源 G蛋白和使用分子动力学模拟和诱变耦合的结构见解功能测定。这些受体-G蛋白复合物之间的相似性和差异将使我们能够对比并比较我们的发现和检查G蛋白偶联和选择性的方面。共同这些研究将使我们能够创建一个详细的机械框架来了解家庭C GPCR 信号传导将构成针对这些受体的新型治疗策略的设计。