Molecular Mechanisms Underlying PSD-MAGUK/NMDA Receptor Interactions

PSD-MAGUK/NMDA 受体相互作用的分子机制

• 批准号: 7910286
• 负责人: MacKenzie A Howard
• 金额: $ 5.05万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7910286
• 关键词: Alzheimer' s Disease; Anatomy; Autistic Disorder; DLG1 gene; Degenerative Disorder; Dendrites; Development; Electrophysiology (science); Future; Genetic; Glutamate Receptor; Glutamates; Goals; Image; Kinetics; Knockout Mice; Learning; Measures; Mediating; Memory; Molecular; Molecular Genetics; Morphology; N-Methyl-D-Aspartate Receptors; Neurons; Physiology; Play; Protein Binding Domain; Protein Family; Proteins; Research; Role; Scaffolding Protein; Schizophrenia; Scientist; Shapes; Signal Transduction; Synapses; Synaptic Transmission; Synaptic plasticity; System; Techniques; Tertiary Protein Structure; base; design; developmental disease; discs, large (Drosophila) homolog 2 protein, rat; in vivo; membrane-associated guanylate kinase; nervous system disorder; overexpression; presynaptic density protein 95; public health relevance; receptor; relating to nervous system; research study; synapse-associated protein 97; trafficking

DESCRIPTION (provided by applicant): The overall objectives of my proposal are to understand the molecular mechanisms by which glutamate receptors, particularly NMDA receptors (NMDARs), interact with synaptic scaffolding proteins and how these interactions shape synaptic transmission. Specifically, I will study how the postsynaptic density-95-like membrane associated guanylate kinase (PSD-MAGUK) protein family, in particular the protein SAP97, traffic NMDA receptors subunits and change their physiology. PSD-MAGUKs and NMDA receptors play a critical role in basal synaptic transmission and learning and memory, and have been implicated in a wide variety of neurological diseases, ranging from developmental disorders such as autism, schizophrenia, to degenerative diseases such as Alzheimer's. My research goals are outlined in two Specific Aims: Specific Aim 1: SAP97 controls AMPA and NMDA receptor trafficking and synaptic morphology. I hypothesize that SAP97 traffics AMPA and NMDARs to synapses during early development and specifically promotes GluN2A-containing NMDARs. Second, I hypothesize that SAP97-mediated signaling also controls dendrite and synapse morphology in developing neurons. I will manipulate SAP97 protein levels in vivo and use electrophysiology and confocal imaging to measure the role of this protein in synaptic transmission and neuronal anatomy. Specific Aim 2: Molecular differences in PSD-MAGUKs underlie NMDAR kinetics and subunit switching. First, I hypothesize that specific protein binding domains shared by PSD-93, -95, and SAP97 promote synaptic trafficking of GluN2A-containing NMDARs while different motifs in SAP102 promote GluN2B- containing receptors. Second, I hypothesize that PSD-MAGUKs also directly influence NMDAR physiology, with each PSD-MAGUK differentially interacting with NMDARs and shaping synaptic currents. I will design and overexpress chimeric PSD-MAGUK proteins in vivo, in NMDAR subunit conditional knockout mice, and measure the effect on NMDARs using electrophysiology. I will also use a heterologous expression system to measure direct interactions between these proteins. Thus, I will define the protein domains responsible for PSD-MAGUK/NMDAR interactions and how these interactions alter NMDAR physiology. These experiments take a multi-dimensional approach to a vital scientific question, combining cutting edge molecular genetic, physiologocial, and anatomical techniques and will enhance our understanding of fundamental molecular mechanisms of synaptic transmission and learning and memory. PUBLIC HEALTH RELEVANCE: My experiments study the interactions between glutamate receptors and the family of proteins that organize them at synapses. These studies will uncover fundamental mechanisms of glutamatergic synaptic transmission, the major form of neural signaling, and synaptic plasticity, the cellular basis of learning and memory. Deficits in synaptic transmission are symptomatic of most neurological diseases. Thus, my results will be relevant both to basic scientists and to clinicians and will guide the way for future studies of learning and memory and the genetic causes of and pharmacological therapies for the alleviation of a variety of neurological diseases.

描述（由申请人提供）：我的提案的总体目标是了解谷氨酸受体，特别是NMDA受体（NMDAR）与突触支架蛋白相互作用的分子机制，以及这些相互作用如何塑造突触传递。具体来说，我将研究如何突触后密度-95样膜相关鸟苷酸激酶（PSD-MAGUK）蛋白家族，特别是蛋白SAP 97，交通NMDA受体亚基和改变他们的生理。PSD-MAGUK和NMDA受体在基础突触传递以及学习和记忆中起关键作用，并且已经涉及多种神经系统疾病，从发育障碍如自闭症、精神分裂症到退行性疾病如阿尔茨海默病。具体目标1：SAP 97控制AMPA和NMDA受体的运输和突触形态。我假设SAP 97交通AMPA和NMDAR突触在早期发展，并特别促进GluN 2A含有NMDAR。其次，我假设SAP 97介导的信号也控制发育中神经元的树突和突触形态。我将在体内操纵SAP 97蛋白水平，并使用电生理学和共聚焦成像来测量这种蛋白在突触传递和神经元解剖中的作用。 具体目标2：PSD-MAGUKs的分子差异是NMDAR动力学和亚基转换的基础。首先，我假设PSD-93、PSD-95和SAP 97共享的特异性蛋白结合结构域促进含GluN 2A的NMDAR的突触运输，而SAP 102中的不同基序促进含GluN 2B的受体。其次，我假设PSD-MAGUKs也直接影响NMDAR生理学，每个PSD-MAGUK与NMDAR不同地相互作用并形成突触电流。我将在NMDAR亚基条件性敲除小鼠体内设计和过表达嵌合PSD-MAGUK蛋白，并使用电生理学测量对NMDAR的影响。我还将使用异源表达系统来测量这些蛋白质之间的直接相互作用。因此，我将定义负责PSD-MAGUK/NMDAR相互作用的蛋白质结构域以及这些相互作用如何改变NMDAR生理学。 这些实验对一个重要的科学问题采取了多维度的方法，结合了尖端的分子遗传学，生理学和解剖学技术，并将增强我们对突触传递和学习记忆的基本分子机制的理解。 公共卫生相关性：我的实验研究谷氨酸受体和在突触处组织它们的蛋白质家族之间的相互作用。这些研究将揭示神经元信号传导的主要形式-突触能突触传递的基本机制，以及学习和记忆的细胞基础-突触可塑性。突触传递的缺陷是大多数神经系统疾病的症状。因此，我的研究结果将与基础科学家和临床医生相关，并将为未来的学习和记忆研究以及减轻各种神经系统疾病的遗传原因和药物治疗提供指导。