Glutamate receptors and human neurological disease

该R35研究计划提案将使用电生理学，分子和结构方法， 探索与神经疾病相关的兴奋性突触功能的多个方面。我们将专注于 阐明和调节突触后谷氨酸受体的功能特性。我们将采取 在cryoEM，遗传学，机器人技术和受体生物学的同步进展的优势，以解决问题， 以前是无法进入的。四种方法将解决我们对突触的理解中的关键差距。 功能并提供对神经系统疾病的治疗相关见解。 首先，我们将探讨健康人对变异的区域不耐受的功能和临床意义。 人群以及新发疾病相关的谷氨酸受体突变，最常见于GRIN 1， GRIN2A、GRIN2B、GRIN2D是基因组中耐受性最差的基因。我们将建立 在健康个体中等位基因频率和功能变化之间的关系，这是必要的， 了解这些基因中SNPs作为疾病风险因素的潜在作用。这些罕见变异的评价 也将为精准医疗提供机会，并促进我们对受体功能的理解。 其次，我们将开发新的化合物进行概念验证研究，以确定新的治疗策略， 神经系统疾病我们将合成激动剂效力和通道开放的亚基选择性调节剂， 评估未充分研究的NMDA受体亚基（例如GluN2C，GluN2D）在神经元回路中的作用的可能性 皮质丘脑和纹状体我们将确定NMDA调节剂的作用部位和机制， 受体，并使用药物化学，以提高大脑渗透，效力和溶解度的合作 和丹尼斯·廖塔在埃默里大学的化学系我们将使用我们开发的药理学工具来深入了解 用于治疗癫痫、中风、帕金森病和阿尔茨海默病。 第三，我们通过开发两类化合物的SAR来探索NMDA受体的偏性调节剂 从而改变离子通道选择性。这些化合物代表了第一个实例， 试剂可以改变通道渗透性质，表明调节剂可以调节通道的不同功能。 NMDA受体。这些化合物作为神经保护剂具有巨大的潜力， 而没有与受体阻断相关的副作用，我们将在体内缺血模型中进行评估。 第四，我们将联合收割机通过对区域不容忍的遗传分析、 变构调节和结构生物学的新进展，以促进我们对机制的理解 将谷氨酸结合转化为通道开放。这些实验将集中在共享区域的 控制通道开放的蛋白质，这是我们的变构调节剂和常见的 与疾病相关的人类突变位点。我们将合作进行cryoEM和晶体学 研究以确定调节剂的结合位点，以及通道结构和功能的关键特征。

This R35 Research Program proposal will use electrophysiological, molecular, and structural approaches to probe multiple aspects of excitatory synaptic function that are relevant for neurological disease. We will focus on the elucidation and modulation of the functional properties of postsynaptic glutamate receptors. We will take advantage of coincident advances in cryoEM, genetics, robotics, and receptor biology to address questions that were previously inaccessible. Four approaches will address critical gaps in our understanding of synaptic function and provide therapeutically-relevant insight into neurological disease. First, we will explore the functional and clinical implications of regional intolerance for variation in the healthy population as well as de novo disease-associated glutamate receptor mutations, most commonly found in GRIN1, GRIN2A, GRIN2B, GRIN2D, genes that are among the least tolerant in the genome. We will establish the relationship in healthy individuals between allelic frequency and functional changes, which is necessary in order to understand the potential role of SNPs in these genes as disease risk factors. Evaluation of these rare variants will also provide opportunities for precision medicine, and advance our understanding of receptor function. Second, we will develop novel compounds for proof-of-concept studies to identify new therapeutic strategies for neurological disorders. We will synthesize subunit-selective modulators of agonist potency and channel open probability to assess the roles of understudied NMDA receptor subunits (e.g. GluN2C, GluN2D) in circuits in cortex, thalamus, and striatum. We will determine the site and mechanism of action of modulators of NMDA receptors, and use medicinal chemistry to improve brain penetration, potency, and solubility in collaboration with Dennis Liotta in Chemistry at Emory. We will use the pharmacological tools that we develop to gain insight into the treatment of epilepsy, stroke, Parkinson’s disease, and Alzheimer’s disease. Third, we explore biased modulators of NMDA receptors by developing the SAR of two classes of compounds that alter ion channel selectivity. These compounds represent the first example whereby a pharmacological agent can alter channel permeation properties, demonstrating that modulators can tune distinct functions of the NMDA receptor. These compounds hold enormous potential as neuroprotectants that diminish cation flux without side effects associated with receptor blockade, which we will evaluate in vivo in models of ischemia. Fourth, we will combine information obtained through genetic analysis of regional intolerance, mechanism of allosteric modulation, and new advances in structural biology to advance our understanding of the mechanisms that convert glutamate binding to channel opening. These experiments will focus on the shared regions of the protein that control channel opening, which are the key sites of action of our allosteric modulators and common sites for disease-associated human mutations. We will collaboratively perform cryoEM and crystallographic studies to determine the binding site for modulators, as well as key features of channel structure and function.