Structure and Function of NMDA Receptors

 描述（由申请人提供）：N-甲基D-天冬氨酸受体是谷氨酸受体的一种亚型，在哺乳动物中枢神经系统中介导兴奋性信号传递。它们的主要功能涉及将化学信号转化为电信号，即谷氨酸与受体中的细胞外结构域结合触发谷氨酸的形成。 受体中的阳离子可渗透跨膜通道。鉴于这些受体在介导许多生理过程中的重要性以及在疾病状态下调节其功能的需要，主要问题是激动剂如何激活蛋白质以及如何调节这种机制。NMDA受体在结构上是调节剂，由氨基末端结构域、激动剂结合结构域、通道区段和C末端结构域组成。在这里，我们建议研究域之间的通信和它们在支配激活和变构调节中的作用。具体而言，我们将研究的作用之间的相互作用的GluN 1激动剂结合结构域与GluN 2亚基在控制激动剂结合结构域的动力学和激活程度（具体目标1），使用发光共振能量转移，smFRET和电生理学的组合。我们还将通过建立从氨基末端结构域开始通过激动剂结合结构域的构象变化来研究变构调节的途径，并研究变构调节期间细胞外结构域的动力学变化（具体目标2）。光谱研究将补充电生理测量，调查在域之间的界面处的改变引起的功能变化。这些功能和结构的调查将提供一个全面的了解的构象途径，以及在NMDA受体功能的激活和变构调节的动力学的作用。

 DESCRIPTION (provided by applicant): N-methyl D-aspartate receptors are a subtype of glutamate receptors that mediate excitatory signal transmission in the mammalian central nervous system. Their primary function involves converting the chemical signal into an electrical signal, i.e. glutamate binding to an extracellular domain in the receptor triggers the formation of cation permeable transmembrane channels in the receptor. Given the importance of these receptors in mediating a number of physiological processes and the need to modulate their function in disease states, the primary questions are how does the agonist activate the protein and how can this mechanism be modulated. The NMDA receptors are modulator in structure consisting of an amino terminal domain, agonist binding domain, channel segments and the C-terminal domains. Here we propose to study the communication between the domains and their role in dictating activation and allosteric modulation. Specifically we will investigate the role o the interactions between GluN1 agonist binding domain with the GluN2 subunit in controlling agonist binding domain dynamics and extent of activation (specific aim 1) using a combination of luminescence resonance energy transfer, smFRET, and electrophysiology. We will also investigate the pathway for allosteric modulation by establishing the conformational changes starting at the amino terminal domain through the agonist binding domain and study the changes in dynamics in the extracellular domains during the allosteric modulation (specific aim 2). The spectroscopic investigations will be complemented by electrophysiological measurements investigating the changes in function induced by alterations at the interface between the domains. These functional and structural investigations will provide a comprehensive understanding of the conformational pathway as well as role of dynamics in activation and allosteric modulation in NMDA receptor function.