Gating and permeation in ionotropic glutamate receptors

离子型谷氨酸受体的门控和渗透

基本信息

批准号：
9927688
负责人：
LONNIE P WOLLMUTH
金额：
$ 42.36万
依托单位：
STATE UNIVERSITY NEW YORK STONY BROOK
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9927688
关键词：
AMPA Receptors Acute Address Affect Agonist Alzheimer&apos s disease brain Binding Biological Assay Brain Brain Diseases C-terminal Cell Death Cells Chemicals Chronic Clinic Communication Complement Coupling Cysteine Data Disease Electrophysiology (science)Elements Epilepsy Event Extracellular Domain Fluorescence Resonance Energy Transfer Free Energy Glutamate Receptor Glutamates Goals Human Inherited Ion Channel Ion Channel Gating Kinetics Learning Ligand Binding Domain Link Measurement Mediating Molecular Mutation N-Methyl-D-Aspartate Receptors NMDA receptor A1 Nervous system structure Neurodevelopmental Disorder Neurotransmitters Outcome Pathway interactions Pharmaceutical Preparations Physiology Positioning Attribute Potassium Channel Property Proteins Publishing Resolution Role Schizophrenia Signal Transduction Societies Specificity Spermine Structure Synapses Synaptic Transmission Testing Transmembrane Domain acute stroke autism spectrum disorder base comparative crosslink de novo mutation disease-causing mutation epileptic encephalopathies excitotoxicity experimental study insertion/deletion mutation mind control molecular dynamics mutation assay nervous system disorder novel operation postsynaptic presynaptic receptor receptor function simulation small molecule stargazin synaptic function

项目摘要

Our long-term goal is to address molecular determinants of brain disorders. Fast synaptic transmission in the brain is mediated by ion channels that are directly activated by a chemical neurotransmitter. NMDA and AMPA receptors are glutamate-gated ion channels that convert the presynaptic release of glutamate, the predominant excitatory neurotransmitter in the brain, into a postsynaptic signal. By defining the operation of NMDA and AMPA receptors, we will gain a better understanding of how they control brain function. We will also learn how to modulate their function with greater precision and specificity to help understand, and potentially treat, brain disroders such as schizophrenia, epilepsy, and the excitotoxicity associated with acute and chronic brain disorders. Our experiments will focus on a eukaryotic transmembrane segment, the M4 segment, which is positioned around the pore domain. Recent published and preliminary data from our lab has indicated that the M4 segments act in novel ways to regulate core synaptic functions of NMDA and AMPA receptors. Highlighting their significance is that inherited and de novo mutations in the M4 segments induce neurodevelopmental disorders and epileptic encephalopathies. Aim 1 will address the novel hypothesis that the unique kinetics of NMDA receptors at synapses are due to two kinetically distinct gates and that the M4 segments regulate these gates in a subunit-specific manner. We will address this hypothesis using cysteine cross-linking, rigorous single channel analysis, and molecular dynamic simulations. Aim 2 will address the hypothesis that the M4 segments in NMDA receptors are a major allosteric conduit coupling external domains to transmembrane and internal domains. Here, we will test this hypothesis by decoupling external domains from transmembrane and internal domains and assay this decoupling using electrophysiological and FRET based measurements. Aim 3 will address the hypothesis that the M4 segments in AMPA receptors carry out distinct functional roles including acting as a conduit for auxiliary proteins found at synapses. Here, we will compare functional properties between the M4 segments in NMDA and AMPA receptors using electrophysiological recordings and molecular dynamic simulations. Our experiments will delineate molecular features of NMDA and AMPA receptors that contribute to synaptic function. This information will aid in developing specific therapies to target these receptors in nervous system disorders.

我们的长期目标是解决大脑疾病的分子决定因素。快速突触大脑中的传输是由离子通道介导的，离子通道直接被化学物质激活神经递质。 NMDA 和 AMPA 受体是谷氨酸门控离子通道，可将突触前释放谷氨酸（大脑中主要的兴奋性神经递质）突触后信号。通过定义 NMDA 和 AMPA 受体的运作，我们将获得更好的结果了解它们如何控制大脑功能。我们还将学习如何调节它们的功能具有更高的精确度和特异性，有助于理解并可能治疗脑部疾病，例如精神分裂症、癫痫以及与急性和慢性脑部疾病相关的兴奋性毒性。我们的实验将重点关注真核生物跨膜片段，即 M4 片段，它是位于孔域周围。我们实验室最近发布的初步数据表明 M4 片段以新颖的方式调节 NMDA 和 AMPA 的核心突触功能受体。强调其重要性的是 M4 片段中的遗传突变和从头突变诱发神经发育障碍和癫痫性脑病。目标 1 将针对小说假设突触处 NMDA 受体的独特动力学归因于两种不同的动力学门，并且 M4 片段以亚基特异性方式调节这些门。我们将解决该假设使用半胱氨酸交联、严格的单通道分析和分子动力学模拟。目标 2 将提出以下假设：NMDA 受体中的 M4 片段是主要的将外部域耦合到跨膜域和内部域的变构导管。在这里，我们将通过将外部域与跨膜域和内部域解耦来检验这一假设使用基于电生理学和 FRET 的测量来分析这种解耦。目标 3 将解决假设 AMPA 受体中的 M4 片段具有不同的功能作用，包括作为突触中发现的辅助蛋白的管道。在这里，我们将比较功能使用电生理学研究 NMDA 和 AMPA 受体 M4 片段之间的特性录音和分子动力学模拟。我们的实验将描述分子特征 NMDA 和 AMPA 受体有助于突触功能。这些信息将有助于开发针对神经系统疾病中这些受体的特定疗法。