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发现N-甲基-D-天冬氨酸（NMDA）受体的亚型特异性和变构功能调制的分子决定因素。 NMDA受体属​​于与哺乳动物大脑中大多数兴奋性突触传播有关的离子型谷氨酸受体（iGlurs）家族。 NMDA受体是由NR1和NR2亚基组成的多聚体门控离子通道，分别与甘氨酸和L-谷氨酸在细胞外结构域（ATD/S1S2）结合。通过甘氨酸和L-谷氨酸与配体结合结构域（S1S2）的结合来介导跨膜离子通道（S1S2）介导或开放，并通过调节化合物的结合（包括苯基乙醇胺，多胺，多胺，Proton和Zn2+与氨基末端域（Amino Amino）末端域（AIND）的结合来调节。 NMDA受体的功能特性取决于其亚型的亚型，这些亚型由四个不同的NR2亚基定义（a a d）。尽管先前已经从NR1和NR2A确定了S12的几个结构，但亚型特异性配体结合和功能的分子基础，包括含有NR2D的NR2D受体的异常缓慢失活动力学，由于缺乏对其他NR2子nit的结构信息，因此未知。此外，NR2亚基中激活和抑制的一般机制仍然是一个悬而未决的问题，因为NR2 S1S2的结构与任何部分激动剂或拮抗剂尚未阐明。最后，由于完全缺乏ATD结构，由调节剂化合物与ATD的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中调节剂结合介导的亚型特异性和变构调制的分子机制。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，配体结合核心（S1S2）和氨基末端结构域（ATD）的细胞外结构域的结构信息将得到诱变，以及电生理学和生物化学实验，以建立NMDA受体的结构功能关系。该提案有两个具体的目标。目的1是了解亚型特异性配体结合，激活，抑制和失活的结构机制。目的2是破译由变构调节剂（包括Zn2+，Ifenprodil，proton和polyamines）与NR1和NR2B ATD的结合介导的NMDA受体活性的分子机制。 NMDA受体一直是药理学研究的主要靶标，因为它们在大脑功能和发育中起关键作用。 NMDA受体的功能障碍与神经和心理健康相关的疾病和伤害有关，包括癫痫发作，精神分裂症，阿尔茨海默氏病和帕金森氏病。这项研究的结果有望帮助设计具有高特异性和效力且具有显着治疗值的ATD和S1S2的新型化合物。