Dynamics Of Ligand Gated Ion Channels

配体门控离子通道的动力学

• 批准号: 10570200
• 负责人: Vasanthi Jayaraman
• 金额: $ 67.78万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10570200
• 关键词: Agonist; Binding; Biochemical; Central Nervous System; Characteristics; Classification; Cognition; Color; Computing Methodologies; Data; Electrophysiology (science); Fluorescence; Glutamate Receptor; Goals; Image; Investigation; Ion Channel Gating; Ions; Isoxazoles; Kainic Acid Receptors; Laboratories; Learning; Ligands; Mediating; Mediator; Memory; Methods; Movement; N-Methylaspartate; Parkinson Disease; Physiological; Physiological Processes; Property; Propionates; Protein Subunits; Proteins; Role; Seizures; Stroke; Structure; Synapses; Synaptic Transmission; conformational conversion; delta receptors; dimer; kainate; nervous system disorder; protein complex; receptor; receptor function; single molecule; single-molecule FRET

PROJECT SUMMARY/ABSTRACT Glutamate receptors mediate the spread of excitation in the mammalian central nervous system, and ultimately control physiological functions such as movement and cognition. They are classified into four subfamilies: N-methyl-D-aspartate (NMDA), -amino-5-methyl-3-hydroxy-4-isoxazole propionate (AMPA), kainate, and delta receptors. All four subtypes are topologically similar, comprising four protein subunits held together as a dimer-of-dimers. However, their gating characteristics and mechanisms are unique, reflecting distinct roles in synaptic transmission. The goal of my laboratory is to understand the mechanisms that underlie the functional fine-tuning of each of these subtypes. Using a multipronged approach that combines biochemical, electrophysiological, fluorescence, and computational methods, we have already identified conformational transitions that are critical for mediating activation and inhibition of AMPA and NMDA glutamate receptors. However, a direct understanding of how such structural changes in one part of the protein control changes in other parts, and how they dictate functional properties, remains unknown. We propose to develop and use multicolor single-molecule fluorescence resonance energy transfer (FRET) to draw structure–function correlations between different segments of each glutamate receptor subtype. We will also focus our efforts on understanding the less well-studied kainate and delta subtypes. Specifically, we will investigate the mechanisms underlying activation and modulation of an abundant form of the kainate receptor by agonists, ions, and auxiliary proteins. In addition, we have preliminary data showing that delta receptor function is dependent on connections with trans-synaptic protein complexes, therefore we will study the structure and function of delta receptors in the context of synaptic binding partners. Together, these investigations will place our fundamental single-molecule investigations in a physiological context, and eventually allow us to understand functional differences between synaptic and non-synaptic glutamate receptors.

项目概要/摘要 谷氨酸受体介导哺乳动物中枢神经系统兴奋的传播，并且 最终控制运动和认知等生理功能。他们分为四类 亚科：N-甲基-D-天冬氨酸酯 (NMDA)、α-氨基-5-甲基-3-羟基-4-异恶唑丙酸酯 (AMPA)、 红藻氨酸和δ受体。所有四种亚型在拓扑上都相似，包含四个蛋白质亚基 一起作为二聚体的二聚体。然而，它们的门控特性和机制是独特的，反映了 在突触传递中发挥不同的作用。我实验室的目标是了解其背后的机制 每个亚型的功能微调。采用多管齐下的方法，结合生化、 通过电生理学、荧光和计算方法，我们已经确定了构象 对于介导 AMPA 和 NMDA 谷氨酸受体的激活和抑制至关重要的转变。 然而，直接了解蛋白质控制部分的这种结构变化如何改变 其他部分以及它们如何决定功能特性仍然未知。我们建议开发和使用 多色单分子荧光共振能量转移（FRET）绘制结构-功能 每种谷氨酸受体亚型不同片段之间的相关性。我们也将重点努力 了解研究较少的红藻氨酸和三角洲亚型。具体来说，我们将研究其机制 激动剂、离子和辅助剂对丰富形式的红藻氨酸受体的潜在激活和调节 蛋白质。此外，我们有初步数据表明 δ 受体功能依赖于连接 与跨突触蛋白复合物，因此我们将研究 δ 受体的结构和功能 突触结合伙伴的背景。总之，这些研究将使我们的基本单分子 在生理背景下进行研究，最终使我们能够理解之间的功能差异 突触和非突触谷氨酸受体。