Control of Glutamate Receptor Function

谷氨酸受体功能的控制

基本信息

批准号：
9105772
负责人：
Stephen F Traynelis
金额：
$ 36.57万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1998
资助国家：
美国
起止时间：
1998-07-10 至 2020-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9105772
关键词：
AMPA Receptors Address Adrenergic Agents Adult Agonist Basal Ganglia Behavior Brain C-terminal Cell Surface Receptors Cell membrane Cell surface Childhood Clinical Complement Complementary DNA Complex Data Disease Engineering Epilepsy Evaluation Funding Glutamate Receptor Glutamates Glycine Health Human Kainic Acid Receptors Knowledge Learning Ligands Literature Masks Mediating Memory Methods Modeling Molecular Mus Mutation N-Methyl-D-Aspartate Receptors N-Methylaspartate NMDA receptor A1 Neurons Patients Pharmacology Positioning Attribute Probability Property Reaction Time Recombinants Role Signal Transduction Spinal Surface Synapses Synaptic Transmission System Techniques Time Transmembrane Domain Work Xenopus oocyte complex R drug development exome sequencing extracellular human disease interest locus ceruleus structure mutant nervous system disorder novel receptor receptor binding receptor function receptor sensitivity research study response stoichiometry synaptic function therapeutic development tool trafficking

项目摘要

DESCRIPTION (provided by applicant): Glutamate receptors mediate a slow Ca2+-permeable component of synaptic transmission, and are comprised of three classes: AMPA, kainate, and NMDA receptors. A great deal of information about how NMDA receptors are assembled, trafficked, and function has been derived primarily from work with recombinant tetrameric NMDA-Rs comprised of two identical GluN1 subunits and two identical GluN2 subunits. However, a large fraction of NMDA-Rs in the adult brain are "triheteromeric" receptors that contain GluN1 plus two different GluN2 subunits (e.g. GluN1/GluN2A/GluN2B). The wealth of functional and structural data describing NMDA-Rs with two identical GluN2 subunits is in stark contrast to a lack of even minimal understanding of the function and pharmacology of receptors that contain 2 different GluN2 subunits. Because highly divergent properties are imparted by different GluN2 subunits, it is impossible to predict the behavior or pharmacology of a receptor that contains two different GluN2 subunits. The question of how NMDA-R function is impacted by two different GluN2 subunits is also relevant for a growing number of apparent disease-causing human NMDA-R mutations (particularly in GluN2A). Heterozygous patients will have a substantial number of receptors with a single copy of the mutant subunit. Because NMDA-Rs with a single mutant subunit will function differently than those with zero or two copies, it is imperative to understand their function and sensitivity to candidate therapies. In order to understand the triheteromeric NMDA-Rs prevalent in native systems and disease, we propose to explore the functional and pharmacological properties of NMDA-Rs that contain two different GluN2 subunits or 0,1,2 copies of disease- associated mutant GluN2 subunits. This will be accomplished using molecular methods developed during the previous funding cycle that allow control of which GluN2 subunits are incorporated into cell surface receptors. The proposed experiments address three aims: Aim 1. What functional properties dominate when two GluN2 subunits reside in a single NMDA-R complex? We will determine which subunit controls the agonist potency, response time course, channel properties, and pharmacological sensitivity of triheteromeric receptors containing two different GluN2 subunits. Aim 2. Does GluN2C require co-assembly with GluN2A or GluN2B for surface expression? We will use new pharmacological tools that are sensitive to GluN2 stoichiometry and evaluation of single channel properties to examine whether receptors with two GluN2C subunits reach the plasma membrane in GluN2C-expressing olfactory neurons, spinal neurons, and adrenergic neurons in locus coeruleus. Aim 3. How do 0, 1, 2 copies of disease-associated human mutations influence NMDA-R function? We will assess glutamate and glycine EC50 in Xenopus oocytes and single channel properties for mutations in transmembrane domain / linkers implicated in gating. Mutations near the extracellular end of the transmembrane helices enhance channel activation.

描述（由申请人提供）：谷氨酸受体介导突触传递的缓慢 Ca2+ 渗透成分，由三类组成：AMPA、红藻氨酸和 NMDA 受体有关 NMDA 受体如何组装、运输和运输的大量信息。该功能主要源自重组四聚体 NMDA-R，该四聚体由两个相同的 GluN1 亚基和两个相同的 GluN2 组成然而，成人大脑中的很大一部分 NMDA-R 是包含 GluN1 和两个不同的 GluN2 亚基（例如 GluN1/GluN2A/GluN2B）的“三异体”受体。相同的 GluN2 亚基与对含有 2 种不同的 GluN2 亚基的受体的功能和药理学缺乏哪怕是最低限度的了解形成鲜明对比。由于不同的 GluN2 亚基具有高度不同的特性，因此无法预测包含两个不同 GluN2 亚基的受体的行为或药理学。两个不同的 GluN2 亚基如何影响 NMDA-R 功能也是一个问题。与越来越多的明显致病的人类 NMDA-R 突变（特别是 GluN2A）相关，将有大量的杂合子患者。由于具有单个突变亚基的 NMDA-R 的功能与具有零个或两个突变亚基的 NMDA-R 受体不同，因此必须了解它们的功能和对候选疗法的敏感性。 -Rs 在天然系统和疾病中普遍存在，我们建议探索包含两个不同的 GluN2 亚基或 0,1,2 个拷贝的疾病相关突变体 GluN2 的 NMDA-Rs 的功能和药理学特性这将使用上一个资助周期中开发的分子方法来实现，该方法允许控制哪些 GluN2 亚基掺入细胞表面受体中。拟议的实验解决了三个目标：目标 1. 当两个 GluN2 亚基存在于一个细胞中时，什么功能特性占主导地位。单个 NMDA-R 复合物？我们将确定哪个亚基控制包含两个不同 GluN2 亚基的三异体受体的激动剂效力、响应时间过程、通道特性和药理学敏感性。目标 2. GluN2C 是否需要与 GluN2A 或 GluN2B 共同组装才能进行表面表达？我们将使用对 GluN2 化学计量敏感的新药理学工具和单通道特性评估来检查具有两个 GluN2C 亚基的受体是否到达 GluN2C- 的质膜。蓝斑中表达嗅觉神经元、脊髓神经元和肾上腺素能神经元。目标 3。如何做。与疾病相关的人类突变的 0, 1, 2 个拷贝会影响 NMDA-R 功能吗？我们将评估非洲爪蟾卵母细胞中的谷氨酸和甘氨酸 EC50 以及涉及门控突变的跨膜结构域/接头的单通道特性。跨膜螺旋增强通道激活。