NRAP-1 control of NMDA receptor-mediated synaptic transmission

NRAP-1 控制 NMDA 受体介导的突触传递

• 批准号: 9810931
• 负责人: Dayton Joshua Goodell
• 金额: $ 6.12万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2021-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9810931
• 关键词: Acute; Alzheimer' s Disease; Apis; Bathing; Belief; Binding; Binding Proteins; Biological; Biological Assay; Biological Models; Brain; Caenorhabditis elegans; Cells; Chemicals; Chimeric Proteins; Chronic; Complex; Defect; Drosophila genus; Electrophysiology (science); Feedback; Funding; Genetic; Genetic Screening; Glutamate Receptor; Glutamates; Goals; Homologous Gene; Human; Image; In Vitro; Information Storage; Investigation; Ion Channel; Ion Channel Gating; Ions; Kinetics; Laboratories; Light; Mediating; Mental Depression; Modification; N-Methyl-D-Aspartate Receptors; N-Methylaspartate; National Institute of Neurological Disorders and Stroke; Nervous system structure; Neurons; Organism; Population; Preparation; Process; Property; Proteins; Reagent; Receptor Signaling; Recombinants; Regulation; Reporting; Research; Role; Schizophrenia; Science; Secondary to; Signal Transduction; Structure; Surface; Synapses; Synaptic Transmission; Synaptic plasticity; System; Therapeutic Intervention; United States National Institutes of Health; Validation; Work; design; drug discovery; experience; experimental study; glutamatergic signaling; in vivo; insight; light gated; mutant; nervous system disorder; neural circuit; neural information processing; neurotransmission; novel; novel strategies; novel therapeutic intervention; postsynaptic; presynaptic; protein expression; receptor function; receptor-mediated signaling; relating to nervous system; response; synaptic function

The NMDA-receptor (NMDAR) subtype of ionotropic glutamate receptors (iGluRs) has fundamental roles in the processing and encoding of information, and in humans, defects in NMDAR signaling are a hallmark of many neurological disorders. A recent surprising and unexpected discovery using a C. elegans genetic screen for modifiers of NMDAR function has revealed that in this organism the NMDAR does not function autonomously as previously thought, and is instead part of a larger signaling complex, requiring for its activation the binding of a presynaptically secreted protein, NRAP-1. In C. elegans, NRAP-1 is rate limiting for NMDAR function, and thus likely controls the magnitude of NMDAR signaling. Therefore, the mechanisms regulating NRAP-1 secretion, such as the changes in neuronal activity that regulate synapse plasticity, are likely to have fundamental roles in synaptic transmission and NMDAR-mediated changes in synapse strength. Aim 1 of this proposal will determine how neuronal activity regulates the secretion of NRAP-1. To accomplish this, genetic modification and elimination strategies combined with chemical and light controlled ion channels to selectively silence or activate neuronal populations will be employed. In vivo live imaging will be used to directly assess NRAP-1 secretion in response to chronic and acute changes in neuronal activity. The results of this aim will provide new mechanistic insights into acute and homeostatic control of NMDAR-mediated signaling and synaptic plasticity. Although NRAP-1 is of critical importance in the gating of NMDARs, we currently lack a mechanistic understanding of this essential process. Aim 2 of this proposal will define NRAP-1's mechanism of action in gating NMDAR-mediated currents. To accomplish this I will use application of purified recombinant NRAP-1 and NRAP-1 mutants to electrophysiological NMDAR preparations. These constructs will be additionally used in in vitro protein-protein binding assays to define the functional domains of NRAP-1 as well as how and where it binds to the NMDAR. The results of this aim will provide insight into the structure and function of the newly identified C. elegans NMDAR signaling complex. Because of the deep evolutionary conservation of iGluRs and glutamatergic signaling, we anticipate that similar signaling mechanisms might also contribute to the regulation of vertebrate NMDAR signaling. Additionally, comparisons of the evolutionary divergence of NMDAR gating made possible by the results of this study will provide fundamental insights into the design and function of NMDARs. Thus, our studies will provide new conceptual framework for drug discovery that could ultimately motivate new approaches for therapeutic intervention in neurological disease characterized by disrupted NMDAR function.

离子型谷氨酸受体（iGluR）的NMDA受体（NMDAR）亚型具有 在信息处理和编码中的基本作用，以及在人类中，NMDAR的缺陷 信号传导是许多神经系统疾病的标志。最近一个令人惊讶和意想不到的发现 使用C.线虫NMDAR功能修饰基因的筛选显示，在这种生物体中， NMDAR并不像以前认为的那样自主运行，而是一个更大的 信号传导复合物，其激活需要结合突触前分泌蛋白NRAP-1。 In C.在线虫中，NRAP-1是NMDAR功能的速率限制，因此可能控制NMDAR的大小。 NMDAR信号。因此，调节NRAP-1分泌的机制，如细胞内蛋白质的变化， 调节突触可塑性神经元活动可能在突触可塑性中具有基本作用。 传递和NMDAR介导的突触强度的变化。本提案的目标1将决定 神经元活动如何调节NRAP-1的分泌。为了实现这一目标，基因改造和 消除策略结合化学和光控离子通道，选择性沉默或 将使用激活的神经元群体。体内实时成像将用于直接评估 NRAP-1分泌响应于神经元活性的慢性和急性变化。这一目标的结果 将为NMDAR介导的急性和稳态控制提供新的机制见解。 信号传导和突触可塑性。虽然NRAP-1在NMDAR的门控中至关重要， 目前我们对这一重要过程缺乏机械性的理解。本提案的目标2将 定义NRAP-1在门控NMDAR介导的电流中的作用机制。为了实现这一目标，我将 将纯化的重组NRAP-1和NRAP-1突变体应用于电生理NMDAR 准备工作。这些构建体将另外用于体外蛋白质-蛋白质结合测定， 定义NRAP-1的功能结构域以及它如何以及在何处结合NMDAR。结果 这一目标的实现将为新发现的C. elegans NMDAR信号复合物。由于iGluRs和谷氨酸能的深层进化保守性， 信号，我们预计类似的信号机制也可能有助于调节 脊椎动物NMDAR信号传导。此外，还比较了NMDAR的进化差异， 本研究的结果使门控成为可能，这将为设计和 NMDAR的功能。因此，我们的研究将为药物发现提供新的概念框架， 可能最终激发神经系统疾病治疗干预的新方法 其特征在于NMDAR功能被破坏。