Functional Architecture of Glutamate Receptor Channels

描述（由申请人提供）：我的实验室的长期目标是了解大脑信号传导的分子机制，特别是与高级大脑功能和疾病状态相关的分子机制。我的实验室主要研究突触生理学，特别是那些使用谷氨酸作为神经递质的突触。谷氨酸受体（GluR）介导大脑的基本信息处理，并参与学习和记忆的细胞和分子机制，细胞连接的发展和维持，以及疼痛的传导和感知。它们还与急性和慢性细胞死亡有关，包括与许多神经系统疾病有关的细胞死亡。本研究的目的是研究GluRs中通道门控的结构基础。这些信息是了解GluRs在脑功能中的基本作用以及开发药物的关键，这些药物可以减轻它们在病理条件下介导的细胞死亡。这一问题将在重组GluRs中使用多种技术进行研究，包括定点诱变、半胱氨酸取代、通道阻滞剂、快速激动剂应用以及全细胞和单通道分析。目的1将研究GluR通道中细胞外前庭的结构，包括它如何与亚基之间的不对称相关。考虑到细胞外前庭的功能意义——它包含具有治疗潜力的孔阻滞剂的位点——定义这个区域是必不可少的。这项工作也构成了Aim2的基础，我们将更具体地研究门控过程中细胞外前庭的构象变化。这些构象变化将配体结合与通道打开结合起来，因此代表了它们功能的基本特征。Aim3将进一步研究与通道门控相关的问题，特别是与脱敏有关的问题。这些实验将为一个重要的生理过程提供关键的见解。这项工作将定义GluR通道结构/功能的基本原理，并为减轻病理条件下GluR介导的细胞死亡提供新的工具和见解。

DESCRIPTION (provided by applicant): The long-term objective of my laboratory is to understand the molecular mechanisms underlying signaling in the brain, especially as it relates to higher brain functions and disease states. My laboratory focuses mainly on synaptic physiology, specifically those synapses that use glutamate as their neurotransmitter. Glutamate receptors (GluR) mediate basic information processing in the brain and contribute to the cellular and molecular mechanisms underlying learning and memory, the development and maintenance of cellular connections, and pain transduction and perception. They have also been implicated in acute and chronic celt death, including that associated with numerous neurological diseases. The goal of the present proposal is to investigate the structural basis of channel gating in GluRs. Such information is key to understanding the fundamental role of GluRs in brain function as well as the development of drugs that attenuate the cell death they mediate under pathological conditions. This issue will be studied in recombinant GluRs using a variety of techniques including site-directed mutagenesis, cysteine substitutions, channel blockers, fast agonist application, and whole cell and single channel analysis. Aim 1 will study the structure of the extracellular vestibule in GluR channels, including how it relates to an asymmetry between subunits. Given the functional significance of the extracellular vestibule--it contains sites for pore blockers with therapeutic potential--defining this domain is essential. This work also forms the basis for Aim2, where we will study more specifically the conformational changes in the extracellular vestibule during gating. These conformational changes couple ligand binding to channel opening and therefore represent fundamental features of their function. Aim3 will further pursue issue related to channel gating specifically to desensitization. These experiments will provide key insights into an important physiological process. This work will define fundamental principles of structure/function in GluR channels and provide new tools and insights into means to attenuate the cell death GluR mediated under pathological conditions.