Molecular Mechanisms of Synaptic G Protein-Coupled Receptors

突触G蛋白偶联受体的分子机制

• 批准号: 9381245
• 负责人: Joshua Levitz
• 金额: $ 40.86万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9381245
• 关键词: Area; Biophysics; Coupling; Dimerization; Disease; Drug Targeting; Energy Transfer; Environment; G-Protein-Coupled Receptors; GABA Receptor; GTP-Binding Protein alpha Subunits, Gs; GTP-Binding Proteins; Glutamates; Goals; Health; Hippocampus (Brain); Kinetics; Lead; Ligand Binding; Ligand Binding Domain; Ligands; Link; Long-Term Depression; Measurement; Measures; Membrane; Mental disorders; Metabotropic Glutamate Receptors; Methods; Molecular; Molecular Conformation; Motion; Nervous system structure; Neurotransmitters; Optical Methods; Optics; Pattern; Pharmacology; Population; Process; Receptor Activation; Reporter; Research; Rhodopsin; Role; Signal Transduction; Specificity; Synapses; Synaptic Transmission; Transmembrane Domain; Work; beta-adrenergic receptor; biological systems; desensitization; detector; dimer; extracellular; glutamatergic signaling; improved; insight; nervous system disorder; neuronal excitability; neurotransmitter release; optical sensor; optogenetics; protein activation; receptor; response; single molecule; spatiotemporal

Project Summary In many biological systems G protein-coupled receptors (GPCRs) provide a crucial molecular link between the dynamics of the extracellular environment and the associated intracellular signaling response. In the nervous system, GPCRs serve as detectors of precise patterns of neurotransmitter release and are able to, in turn, modulate neuronal excitability and synaptic transmission. Of particular importance are the class C metabotropic glutamate (mGluR) and GABA receptors (GABABR), which respond to the major excitatory and inhibitory neurotransmitters, respectively, and serve as drug targets for neurological and psychiatric disorders. Unfortunately, our understanding of their underlying molecular mechanisms of signaling remain limited due to a lack of methods for the direct measurement and manipulation of their activity with high specificity and spatial and temporal precision. Furthermore, the biophysical activation mechanism of class C GPCRs is particularly challenging to decipher because unlike class A GPCRs, such as rhodopsin or ß-adrenergic receptors, they contain large, extracellular ligand binding domains (LBDs) that multimerize and couple, via a poorly understood mechanism, to a transmembrane domain (TMD). Our recent work has established new optical methods for directly measuring mGluR assembly and conformational dynamics at the single molecule level and has also produced an optogenetic method to manipulate receptors with subtype selectivity and high spatiotemporal precision using photoswitchable tethered ligands. These breakthroughs have advanced our understanding of how mGluRs dimerize and the initial molecular motions that lead to cooperative receptor activation, but many fundamental questions remain. In research area 1 we will dissect the activation mechanism of mGluRs and GABABRs in a quantitative, interdisciplinary way using optical approaches, including single molecule Forster resonance energy transfer (FRET) to measure conformational dynamics, in conjunction with functional reporters and detailed structural analysis. The long-term goal is to understand, biophysically, how allosteric inter-domain and inter-subunit coupling interactions permit orthosteric and allosteric ligand binding to produce G protein activation. This work will give major insight into the fundamental activation processes of a large class of membrane receptors and should provide a deeper understanding of their molecular pharmacology. In research area 2 we will improve and harness the power of optical sensors of activation and optogenetic control of receptors to probe the kinetics of different mGluR subtypes at the level of activation, signaling, and desensitization and to dissect their spatiotemporal signaling profiles at hippocampal synapses. In the long term we plan to use this information to probe the mechanism of induction of long-term depression by pre-synaptic, post-synaptic, and glial mGluR populations. This work will provide a dynamic picture of mGluR signaling that has been missing from the field and will strengthen our molecular understanding of the role of these receptors in synaptic modulation in health and disease.

项目摘要 在许多生物系统中，G蛋白偶联受体（GPCR）在动力学之间提供了至关重要的分子联系 细胞外环境和相关的细胞内信号反应。在神经系统中，GPCR作为 神经递质释放精确模式的检测器，并能够调节神经元令人兴奋和突触 传播。特别重要的是C类代替谷氨酸（MGLUR）和GABA受体（GABABR） 分别应对主要兴奋和抑制性神经递质，并作为神经系统和 精神疾病。不幸的是，我们对信号传导的潜在分子机制的理解仍然有限 由于缺乏直接测量和操纵其活动的方法，以高特异性和空间和 临时精度。此外，C类GPCR的生物物理激活机制对于破译特别具有挑战性 因为与A类GPCR（例如Rhodopsin或β-肾上腺素受体不同，它们都包含大的细胞外配体结合 通过较少了解的机制，将多种型和夫妇跨到跨膜结构域（TMD）的域（LBD）。 我们最近的工作已经建立了新的光学方法，用于直接测量MGLUR组装和构象 单分子水平的动力学，还产生了一种以亚型操纵接收器的光遗传学方法 选择性和高空间时间精度使用可拍照的绑线配体。这些突破已经提高了我们的 了解MGLURS如何二聚和导致合作受体激活的初始分子运动，但许多 仍然存在基本问题。在研究区域1中，我们将剖析mglurs和gababrs的激活机制 使用光学方法的定量，跨学科的方式，包括单分子福斯特共振能 转移（FRET）与功能记者结合使用和详细的结构，以测量构象动力学 分析。长期的目标是从生物物理上理解变构间和增生耦合相互作用 允许定位和变构的配体结合以产生G蛋白激活。这项工作将使人们对 大量膜接收器的基本激活过程，应更深入地了解其 分子药理学。在研究区域2中，我们将改善和利用激活和激活传感器的力量 对受体的光遗传控制，以探测不同mglur亚型的动力学，在激活，信号，信号， 并脱敏并在海马突触上剖析其时空信号传导曲线。长期 我们计划使用此信息来探测引入长期抑郁症的机理，这突触前，突触后， 和胶质mglur种群。这项工作将提供动态的MGLUR信号传导的动态图片 并将加强我们对这些受体在健康和疾病中突触调节中的作用的分子理解。