Structure and Finction of AMPA subtype ionotropic glutamate receptors

AMPA 亚型离子型谷氨酸受体的结构和功能

基本信息

批准号：
9091657
负责人：
Alexander Sobolevsky
金额：
$ 34.93万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-30 至 2018-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9091657
关键词：
AMPA Receptors Acids Adamantane Agonist Alzheimer&apos s Disease Amyotrophic Lateral Sclerosis Binding Binding Sites Biochemical Calcium Cations Chemicals Clinical Complex Computer Simulation Crystallization Cysteine Data Detergents Down-Regulation Drug Design Electrophysiology (science)Engineering Entropy Epilepsy Fluorescence Glutamate Agonist Glutamate Receptor Glutamates Goals Integral Membrane Protein Ion Channel Ischemia Kinetics Knowledge Length Ligands Lipids Location Mediating Methods Modeling Modification Molecular Molecular Conformation Molecular Sieve Chromatography Mutation Neuraxis Neurons Neurosciences Patients Pharmaceutical Preparations Polyamines Primary Lateral Sclerosis Process Proteins Rattus Regulation Resolution Site-Directed Mutagenesis Structural Models Structure Surface Techniques Temperature Testing Therapeutic Toxin Work base chemical synthesis crosslink desensitization design electron density excitotoxicity improved ion channel blocker nervous system disorder neuron loss neurotransmission novel therapeutics public health relevance receptor receptor function research study response

项目摘要

DESCRIPTION (provided by applicant): AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) subtype ionotropic glutamate receptors mediate the majority of excitatory neurotransmission in the central nervous system. Alteration in AMPA receptor function is associated with numerous devastating neurological diseases including Alzheimer's disease, amyotrophic lateral sclerosis, epilepsy and ischemia. Regulation of AMPA receptor activity is therefore an important clinical goal. AMPA receptors function by opening their ion channel for the flow of permeant cations in response to binding of agonist glutamate to the receptor. This process of ion channel opening or activation gating is accompanied by typically slower process of desensitization. Desensitization leads to the closure of the ion channel pore and appears as a 10-500 fold reduction of AMPA receptor- mediated currents in the continuous presence of glutamate. Desensitization represents a natural way of suppressing AMPA receptor activity that protects neurons from the excitotoxic calcium overload. Enhancing or weakening desensitization is therefore an effective way of regulating AMPA receptor activity in pathological conditions. An alternative way to suppress AMPA receptor activity that has therapeutic potential is to use ion channel blockers, molecules that plug the channel pore. At the molecular level, desensitization and ion channel block are expected to have common features that allow them to lock the ion channel in the closed conformation. We plan to study AMPA receptor desensitization and block using a combination of structural and functional approaches and to reveal similarities and differences in these processes. Accordingly, our specific aims are: 1) Obtaining a high-resolution structure of an AMPA receptor in the desensitized state and 2) Building a structural model of ion channel block. AMPA receptor is a challenging target for structure-functional studies because it represents a multimeric integral membrane protein of a large size with typically low expression level. To achieve our goals, we will use a combination of structural and functional approaches including modern crystallographic techniques, Fluorescence-based Size Exclusion Chromatography (FSEC) and electrophysiology. We will use different crystallization methods and temperatures, screen detergents, lipids and ligands to obtain full length AMPA receptor structures in the desensitized and blocker-bound states. We will then combine nascent structural information with electrophysiological recordings and kinetic modeling to figure out mechanisms of AMPA receptor desensitization and block. Achieving our aims will have a significant impact on molecular neuroscience and will result in a new structural/functional model of AMPA receptor that can serve as a dynamic template for theoretical prediction, in silico fitting and chemical synthesis of new compounds that can be tested in different models of neurological diseases and eventually become safe and effective medications.

描述（由适用提供）：AMPA（α-氨基-3-羟基-5-甲基-4-异恶唑丙酸）亚型谷氨酸受体亚型介导大多数中枢神经系统中的大多数兴奋性神经传递。 AMPA受体功能的改变与许多毁灭性神经系统疾病有关，包括阿尔茨海默氏病，肌萎缩性侧面硬化症，癫痫和缺血。因此，调节AMPA受体活性是一个重要的临床目标。 AMPA接收器通过打开其离子通道来响应激动剂谷氨酸与受体的结合而开放其渗透阳离子流的离子通道。离子通道打开或激活门的过程通常是通过脱敏过程较慢来完成的。脱敏会导致离子通道孔的闭合，并在连续存在谷氨酸时显示为AMPA接收器介导的电流的10-500倍。脱敏代表了抑制AMPA受体活性的一种自然方法，该方法可保护神经元免受兴奋性毒性钙的过载。因此，增强脱敏是在病理条件下控制AMPA受体活性的有效方法。抑制具有治疗潜力的AMPA受体活性的另一种方法是使用离子通道阻滞剂，即插入通道孔的分子。在分子水平上，脱敏和离子通道块有望具有共同的特征，使它们可以将离子通道锁定在闭合构象中。我们计划使用结构和功能方法的组合研究AMPA接收器脱敏并阻止，并揭示这些过程中的相似性和差异。彼此之间，我们的具体目的是：1）在脱敏状态下获得AMPA接收器的高分辨率结构，以及2）构建离子通道块的结构模型。 AMPA接收器是结构功能研究的挑战目标，因为它代表了具有通常低表达水平的大尺寸的多聚体积分膜蛋白。为了实现我们的目标，我们将结合结构和功能方法的结合，包括现代晶体学技术，基于荧光的尺寸排除色谱（FSEC）和电生理学。我们将使用不同的结晶方法和温度，筛选确定，脂质和配体以在结合和阻断器结合状态下获得全长AMPA受体结构。然后，我们将将新生的结构信息与电生理记录和动力学建模相结合，以找出AMPA受体脱敏和阻滞的机制。实现我们的目标将对分子神经科学产生重大影响，并将导致一种新的AMPA受体的结构/功能模型，可以作为理论预测的动态模板，在硅酸盐拟合和化学合成的新化合物中可以在不同模型的神经疾病中测试的新化合物，有时会在神经疾病的不同模型中进行测试，有时会成为安全和有效的药物。