Dynamics of ligand gated ion channels

配体门控离子通道的动力学

• 批准号: 9276535
• 负责人: Vasanthi Jayaraman
• 金额: $ 23.01万
• 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 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9276535
• 关键词: AMPA Receptors; Affinity; Agonist; Architecture; Biochemical; Biophysics; C-terminal; Calmodulin; Characteristics; Communication; Dimerization; Disease; Extracellular Domain; Gated Ion Channel; Glutamate Receptor; Investigation; Ion Channel Gating; Isoxazoles; Kainic Acid Receptors; Laboratories; Learning; Ligands; Mediating; Mediator of activation protein; Memory; Methods; Molecular Conformation; Mutation; N-Methyl-D-Aspartate Receptors; N-Methylaspartate; Neuraxis; Parkinson Disease; Pathway interactions; Permeability; Phosphorylation; Physiological Processes; Post-Translational Protein Processing; Property; Propionates; Roentgen Rays; Role; Seizures; Signal Transduction; Stroke; Structure; Synaptic Transmission; Translating; Work; alpha Actinin; base; cognitive function; crosslink; desensitization; dimer; insight; luminescence resonance energy transfer; motor control; nervous system disorder; receptor; response; single-molecule FRET; small molecule

PROJECT SUMMARY/ABSTRACT Glutamate receptors mediate excitatory responses in the mammalian central nervous system, and ultimately control motor and cognitive functions. Glutamate receptors are classified into three subfamilies based on affinity profiles for several synthetic and natural agonists: N-methyl-D-aspartate (NMDA), -amino-5-methyl-3- hydroxy-4-isoxazole propionate (AMPA) and kainate receptors. All three subtypes are broadly similar having a dimer of dimer architecture with similar topologies. However, their gating characteristics and mechanisms are unique resulting in unique roles in synaptic transmission. The work in my laboratory focuses on understanding the mechanisms underlying the fine-tuning of each of these subtypes. AMPA receptors mediate fast synaptic transmission and their gating properties are modulated by the presence of auxiliary subunits (TARPs) as well as through post-translational modifications. Work from my laboratory has provided insight into the mechanism of activation and desensitization in AMPA receptors using a combination of biophysical and biochemical methods. Here, we propose to study how these mechanisms can be translated to modulation by TARPs and post-translational modifications such as phosphorylation. For this we will use a combination of smFRET and LRET to determine the dynamics and conformational changes, and validate these structure-dynamic changes through functional characterization of changes elicited by biochemical manipulations of the receptor like cross linking and mutations. The NMDA receptors, on the other hand, mediate Ca2+ permeable long depolarizing signals and are modulated through small molecule modulators, phosphorylation and interacting partners such as calmodulin and alpha-actinin at the intracellular carboxy terminus. smFRET and LRET investigations from my laboratory as well as the X-ray and EM structures have provided significant insight into conformational changes within the ordered extracellular domains. However, the communication across domains and the role of the disordered C-terminal domain are largely unexplored. Here we propose to study the role of interactions across domains in controlling dynamics and conformational changes in the receptor, and effects of modulators and changes at the C-terminal domain on these interactions and conformational dynamics. These studies will then be correlated to functional consequences thus providing insight into the structure-dynamic pathway of activation, desensitization, and modulation in these receptors.

项目摘要/摘要 谷氨酸受体介导哺乳动物中枢神经系统中的兴奋反应，并最终 控制电动机和认知功能。基于 几种合成和天然激动剂的亲和力谱：N-甲基-D-天冬氨酸（NMDA），-氨基-5-甲基-3-- 羟基-4-异恶唑丙酸（AMPA）和海藻酸盐接收器。所有三个子类型都与 具有相似拓扑结构的二聚体体系结构的二聚体。但是，它们的门控特征和机制是 唯一导致在突触传输中发挥独特作用。我实验室的工作专注于理解 这些亚型的微型调整的基础机制。 AMPA接收器介导快速突触 传输及其门控特性也通过辅助亚基（防水布）的存在调节 与翻译后修改一样。我实验室的工作提供了对机制的见解 使用生物物理和生化的组合在AMPA受体中的激活和脱敏 方法。在这里，我们建议研究如何将这些机制转化为TARPS和 翻译后修饰，例如磷酸化。为此，我们将使用SMFRET和 lret确定动态和概念变化，并验证这些结构动态变化 通过对接收器的生化操作引起的变化的功能表征，例如交叉 连接和突变。另一方面，NMDA接收器介导Ca2+可渗透的长度去极化 信号，并通过小分子调节剂，磷酸化和相互作用伙伴进行调节 如细胞内羧基末端的钙调蛋白和α-肌动蛋白。 SMFRET和LRET调查 我的实验室以及X射线和EM结构为构象提供了重大的见解 有序的细胞外域内变化。但是，跨领域的交流和角色 无序的C末端结构域的大部分是出乎意料的。在这里，我们建议研究相互作用的作用 在控制接收器的动态和构象变化方面的跨域以及调节器的影响 以及在这些相互作用和构象动力学上的C末端域的变化。这些研究会 然后与功能后果相关，从而提供了对结构动力途径的见解 这些受体的激活，脱敏和调节。