Structure and Function of NMDA Receptors

NMDA 受体的结构和功能

• 批准号: 8628178
• 负责人: Hiroyasu Furukawa
• 金额: $ 46.78万
• 依托单位: COLD SPRING HARBOR LABORATORY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8628178
• 关键词: Affinity; Agonist; Allosteric Regulation; Alzheimer' s Disease; Binding; Biochemical; Brain; Complement; Complex; Coupled; Crystallography; Development; Disease; Electrophysiology (science); Extracellular Domain; Family; Family member; Functional disorder; Gated Ion Channel; Glean; Glutamate Receptor; Glutamates; Glycine; Goals; Injury; Ion Channel; Kinetics; Knowledge; Ligand Binding; Ligand Binding Domain; Ligands; Mediating; Mental Health; Molecular; Molecular Structure; Mutagenesis; N-Methyl-D-Aspartate Receptors; NR1 gene; Names; Nature; Neurologic; Neurons; Neurotransmitters; Parkinson Disease; Pattern; Play; Polyamines; Property; Protons; Public Health; Research; Research Design; Role; Schizophrenia; Seizures; Signal Transduction; Site-Directed Mutagenesis; Specificity; Speed; Stroke; Structure; Structure-Activity Relationship; Synaptic Transmission; Techniques; Therapeutic; Variant; Zinc; base; design; extracellular; ifenprodil; insight; mental health related disorder; novel; novel therapeutics; public health relevance; receptor; research study; stem; three dimensional structure

DESCRIPTION (provided by applicant): The overall goal of this project is to uncover molecular determinants for subtype specificity and allosteric functional modulations of N-methyl-D-aspartate (NMDA) receptors. NMDA receptors belong to a family of ionotropic glutamate receptors (iGluRs) involved in the majority of excitatory synaptic transmission in the mammalian brain. NMDA receptors are multimeric ligand-gated ion channels composed of NR1 and NR2 subunits that bind to glycine and L-glutamate at the extracellular domain (ATD/S1S2), respectively. Gating or opening of transmembrane ion channels is mediated by binding of both glycine and L-glutamate to the ligand- binding domain (S1S2) and are allosterically modulated by binding of modulator compounds including phenylethanolamines, polyamines, protons, and Zn2+ to the amino terminal domain (ATD). The functional properties of NMDA receptors differ significantly depending on their subtypes that are defined by four distinct NR2 subunits (A though D). Although several structures have been previously determined for the S1S2 from NR1 and NR2A, the molecular basis for subtype specific ligand-bindings and functions including exceptionally slow deactivation kinetics of the NR2D containing NMDA receptors is unknown due to a lack of structural information on the other NR2 subunits. Furthermore, the general mechanism of activation and inhibition in the NR2 subunits remains an open question because the structure of the NR2 S1S2 in complex with any partial agonist or antagonist has yet to be elucidated. Finally, the molecular mechanism for allosteric modulation mediated by the binding of modulator compounds to the ATD remains elusive due to a complete lack of the ATD structures. Thus, our goal is to obtain the atomic view of the ATD and S1S2 of the NMDA receptors to reveal the molecular mechanism for subtype specificity and allosteric modulation mediated through modulator binding in the ATD. The experimental plan combines x-ray crystallography, electrophysiology, and biochemical techniques. The structural information of the extracellular domain of the NMDA receptors, ligand-binding core (S1S2), and amino terminal domain (ATD), will be complemented by mutagenesis coupled with electrophysiology and biochemical experiments to establish the structure-function relationships of the NMDA receptors. There are two specific aims in this proposal. Aim 1 is to understand the structural mechanism for the subtype specific ligand-bindings, activation, inhibition, and deactivation mediated through NR2 S1S2. Aim 2 is to decipher the molecular mechanism underlying allosteric modulation of the NMDA receptor activity mediated by the binding of allosteric modulators, including Zn2+, ifenprodil, proton, and polyamines, to the NR1 and NR2B ATDs. The NMDA receptors have been a major target for pharmacological studies because they play pivotal roles in brain function and development. Dysfunction of the NMDA receptors is implicated in neurological and mental health related diseases and injuries, including seizure, schizophrenia, Alzheimer's disease, and Parkinson's disease. The results of this research are expected to help design novel compounds that target the ATD and S1S2 with high specificity and potency and with significant therapeutic values.

描述（由申请人提供）：该项目的总体目标是揭示 N-甲基-D-天冬氨酸 (NMDA) 受体亚型特异性和变构功能调节的分子决定因素。 NMDA 受体属于离子型谷氨酸受体 (iGluR) 家族，参与哺乳动物大脑中大部分兴奋性突触传递。 NMDA 受体是由 NR1 和 NR2 亚基组成的多聚体配体门控离子通道，分别与胞外域 (ATD/S1S2) 的甘氨酸和 L-谷氨酸结合。跨膜离子通道的门控或开放是通过甘氨酸和 L-谷氨酸与配体结合结构域 (S1S2) 的结合介导的，并通过调节剂化合物（包括苯乙醇胺、多胺、质子和 Zn2+）与氨基末端结构域的结合进行变构调节（ATD）。 NMDA 受体的功能特性根据其由四个不同 NR2 亚基（A 至 D）定义的亚型而显着不同。尽管之前已经确定了 NR1 和 NR2A 的 S1S2 的几种结构，但由于缺乏其他 NR2 的结构信息，亚型特异性配体结合和功能（包括含有 NMDA 受体的 NR2D 的异常缓慢的失活动力学）的分子基础尚不清楚。亚单位。此外，NR2亚基激活和抑制的一般机制仍然是一个悬而未决的问题，因为与任何部分激动剂或拮抗剂复合的NR2 S1S2的结构尚未阐明。最后，由于完全缺乏 ATD 结构，由调节剂化合物与 ATD 结合介导的变构调节的分子机制仍然难以捉摸。因此，我们的目标是获得 NMDA 受体的 ATD 和 S1S2 的原子视图，以揭示通过 ATD 中的调节剂结合介导的亚型特异性和变构调节的分子机制。该实验计划结合了 X 射线晶体学、电生理学和生化技术。 NMDA受体胞外结构域、配体结合核心(S1S2)和氨基末端结构域(ATD)的结构信息将通过诱变结合电生理学和生化实验来补充，以建立NMDA受体的结构-功能关系。该提案有两个具体目标。目标 1 是了解通过 NR2 S1S2 介导的亚型特异性配体结合、激活、抑制和失活的结构机制。目标 2 是破译 NMDA 受体活性变构调节的分子机制，该活性由变构调节剂（包括 Zn2+、艾芬地尔、质子和多胺）与 NR1 和 NR2B ATD 的结合介导。 NMDA 受体一直是药理学研究的主要目标，因为它们在大脑功能和发育中发挥着关键作用。 NMDA 受体功能障碍与神经和心理健康相关的疾病和损伤有关，包括癫痫、精神分裂症、阿尔茨海默病和帕金森病。这项研究的结果预计将有助于设计针对 ATD 和 S1S2 的新型化合物，具有高特异性和效力，并具有显着的治疗价值。