The Functional Significance of Conformational States in Glutamatergic Signaling

谷氨酸信号传导中构象态的功能意义

基本信息

批准号：
8210352
负责人：
Catherine Lourdes Salussolia
金额：
$ 3.2万
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：
2011
资助国家：
美国
起止时间：
2011-01-01 至 2013-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8210352
关键词：
AMPA Receptors Acute Address Adopted Adverse effects Agonist Alzheimer&apos s Disease Anabolism Biological Assay Cells Charge Chronic Clinical Coma Complex Coupling Cysteine Data Disease Drowsiness Electrophysiology (science)Electrostatics Epilepsy Exhibits Functional disorder Generations Glutamate Receptor Glutamates Goals Hallucinations Immunoblotting Ion Channel Kainic Acid Receptors Kinetics Lead Length Ligand Binding Domain Mediating Memantine Mental disorders Molecular Conformation Mood Disorders Multiple Sclerosis Mutation N-Methyl-D-Aspartate Receptors Nerve Degeneration Neuraxis Neurodegenerative Disorders Neurotransmitters Parkinson Disease Play Positioning Attribute Role Schizophrenia Signal Transduction Site-Directed Mutagenesis Stroke Structure Synaptic Transmission Techniques Therapeutic Agents Transmembrane Domain base excitotoxicity immunocytochemistry innovation insight kainate nervous system disorder neurotransmission novel novel strategies novel therapeutics patch clamp polypeptide public health relevance receptor receptor function receptor structure function research study

项目摘要

DESCRIPTION (provided by applicant): Most fast excitatory synaptic transmission in the central nervous system is mediated by the neurotransmitter glutamate. Aberrant glutamatergic neurotransmission, most notably of the NMDA receptor subtype, has been implicated in a wide variety of nervous system diseases including psychiatric disorders (e.g. schizophrenia and mood disorders), chronic neurodegenerative diseases (e.g. multiple sclerosis and Parkinson's and Alzheimer's diseases), and disorders arising from acute excitotoxicity (e.g. epilepsy and stroke). Accordingly, there is a great need for pharmacological agents that target dysfunctional glutamatergic signaling without resulting in the alteration of its normal function or the occurrence of adverse side effects (e.g. drowsiness, hallucinations, and coma). There are presently few glutamatergic-based therapies available for clinical use, but those agents that are clinically useful (amantidine and memantine) share a common theme: they modulate NMDA receptor gating (opening/closing of the ion channel) in an activity-dependent manner. Thus, understanding gating mechanisms are critical to developing novel therapeutic agents. Glutamate receptors (GluRs) are tetramers being composed of identical or similar subunits. Recently, a crystal structure of a nearly intact AMPA receptor, composed of identical subunits, showed that the receptor subunits exist in two unique conformations (termed 'A/C' and 'B/D') with subunits of the same conformation being positioned opposite one another. Functional NMDA receptors are obligate heterotetramers predominantly comprised of two GluN1 and two GluN2 subunits that adopt the 'A/C' and 'B/D' conformations respectively. In addition, native GluR subtypes (AMPA and kainate) are thought to be heterotetramers composed of at least two different subtypes. The major goal of my proposal is to study the significance of these two conformations in heteromeric AMPA and kainate receptors (Aim 1) and its significance to glutamate receptor gating (Aim 2). To address these aims, I will take advantage of specific cysteine-substituted mutations in the M3-S2 linkers, a short polypeptide that connects the ligand-binding domain to the ion channel pore, to determine a subunit's general conformation through the use of immunoblots and functional assays (patch-clamp electrophysiology). To delineate the significance of distinct conformational states in receptor function, I will alter the physical length and electrostatic composition of the M3-S2 linkers in obligate heteromultimeric NMDA receptors. Through the use of varying agonists and antagonists, the resulting data will provide insights into the gating mechanisms underlying glutamatergic signaling and allow for the innovation and generation of specific pharmacological agents aimed to treat glutamate-based diseases. PUBLIC HEALTH RELEVANCE: Glutamate receptor dysfunction has been implicated in many pathological nervous system disorders including psychiatric, neurodegenerative, and neurodevelopmental diseases. Clinically few glutamate-based therapies exist due to their non-selective targeting of glutamate receptors and of these, the most promising agents target specific aspects of glutamate receptor gating. Thus, by defining novel aspects of glutamate receptor structure-function my studies will serve to further understand glutamate receptor gating and may lead to novel strategies to treat glutamate-based neurological diseases.

描述（由申请人提供）：中枢神经系统中最快速的兴奋性突触传播是由神经递质谷氨酸介导的。异常的谷氨酸神经递质，最著名的是NMDA受体亚型，与多种神经系统疾病有关，包括精神疾病（例如精神分裂症和情绪疾病），慢性神经退行性疾病（例如，多种菌丝和帕金森氏症），慢性神经退行性疾病（例如）兴奋性毒性（例如癫痫和中风）。因此，非常需要靶向功能失调的谷氨酸能信号传导的药理学剂，而不会导致其正常功能的改变或出现不良副作用（例如嗜睡，幻觉和昏迷）。目前，很少有基于谷氨酸能的疗法可用于临床使用，但是那些在临床上有用的药物（amantidine and Memantine）具有共同的主题：它们以活动依赖性方式调节NMDA受体门控（离子通道的开放/关闭）。因此，了解门控机制对于开发新型治疗剂至关重要。谷氨酸受体（胶质）是由相同或相似亚基组成的四聚体。最近，由相同亚基组成的几乎完整的AMPA受体的晶体结构表明，受体亚基以两个独特的构象（称为“ a/c”和“ b/d”）存在，而相同构型的亚基则位于彼此对立。功能性NMDA受体是义务的异驱精，主要由两个Glun1和两个Glun2亚基组成，分别采用了“ A/C”和“ B/D”构型。此外，天然的Glur亚型（AMPA和海藻酸盐）被认为是由至少两个不同的亚型组成的异驱动器。我的提议的主要目标是研究这两种构象在异源AMPA和海藻酸盐受体中的重要性（AIM 1）及其对谷氨酸受体门控的意义（AIM 2）。为了解决这些目的，我将利用M3-S2接头中的特定半胱氨酸溶解的突变，这是一种将配体结合域与离子通道孔连接起来的短多肽，通过使用免疫印迹和功能分析（Patch-lamp Expertophampepthampypophypophypophypophymysigysy）来确定亚基的一般构象。为了描述不同构象状态在受体功能中的重要性，我将改变强制异源性NMDA受体中M3-S2接头的物理长度和静电组成。通过使用不同的激动剂和拮抗剂，所得数据将为谷氨酸能信号传导的门控机制提供见解，并允许创新和生成旨在治疗谷氨酸疾病的特定药理剂。公共卫生相关性：谷氨酸受体功能障碍与许多病理神经系统疾病有关，包括精神病，神经退行性和神经发育疾病。由于其非选择性靶向谷氨酸受体，因此临床上很少有基于谷氨酸的疗法，其中最有希望的药物靶向谷氨酸受体门控的特定方面。因此，通过定义谷氨酸受体结构功能的新方面，我的研究将进一步了解谷氨酸受体门控，并可能导致治疗基于谷氨酸神经系统疾病的新型策略。