RUI: Understanding Steroid Regulation of Ionotropic Glutamate Receptors

智力价值神经元之间的交流受到多种机制的调节。谷氨酸是中枢神经系统中主要的快速兴奋性神经递质，其主要靶点之一是位于突触后神经膜的离子型谷氨酸受体(IGluRs)。离子型谷氨酸受体是一类配体门控离子通道，包括AMPA、海人藻酸和NMDA受体。当与谷氨酸结合时，非选择性阳离子通道的开放允许正电荷的流入，导致突触后细胞去极化，从而传播动作电位。这些受体受到仔细的调控。内源性硫化类固醇、孕烯醇酮硫酸盐和孕烯醇酮硫酸酯在结构上非常相似，已被证明对这些受体有不同的调节作用。Gentile实验室之前的研究表明，这些类固醇结合到两个胞外结构域中的一个，这取决于iGluR家族成员。以此为平台，高分辨率结构研究、计算研究和突变分析的组合现在将允许在详细的分子水平上理解这一调节。目标是了解哪些结合事件和构象变化导致iGluR通道的打开(和动作电位的传播)，以及哪些导致其关闭。广泛的影响该项目的更广泛的影响集中在激发和培训下一代学生在科学发现的过程中。这项研究将为里士满大学(UR)的本科生提供高质量、注重结果的跨学科培训。此外，它还将让弗吉尼亚州里士满的高中化学和生物教师参与一项基于探究的调查，这将使他们能够开发从生物物理学到分子生物学的范围内的新技术，收集想法以融入新的课程或实验室，获得专业发展点，并将他们介绍给可以作为未来导师的UR教职员工。它还将让高中生参与暑期研究，这将使他们发展批判性思维和解决问题的技能，以及让他们接触到科学的刺激。

Intellectual MeritThere are many mechanisms by which communication between neurons is regulated. Glutamate, the major fast excitatory neurotransmitter in the central nervous system, has, as one of its prime targets, the ionotropic glutamate receptors (iGluRs) which reside in the postsynaptic neural membrane. Ionotropic glutamate receptors are a family of ligand gated ion channels, which include AMPA, kainate, and NMDA receptors. Upon binding to glutamate, the opening of a nonselective cation channel allows an influx of positive charge, leading to postsynaptic cell depolarization, and hence propagation of the action potential. These receptors are carefully regulated. The endogenous sulfated steroids, pregnenolone sulfate and pregnenolone sulfate, which are structurally very similar, have been shown to differentially regulate these receptors. Previous research from the Gentile lab has shown that these steroids bind to one of two extracellular domains, dependant upon the iGluR family member. Using this as a platform, a combination of high resolution structural studies, computational studies, and mutational analysis will now allow for an understanding of this regulation on a detailed molecular level. The goal is to understand which binding events and conformational changes lead to an opening of the iGluR channel (and propagation of the action potential) and which lead to its closing.Broader Impacts The broader impacts of this project are focused both on exciting and training the next generation of students in the process of scientific discovery. This research will provide high quality, outcome-oriented, interdisciplinary training to undergraduates at the University of Richmond (UR). In addition, it will involve high school chemistry and biology teachers in Richmond, VA in an inquiry based investigation, which will enable them to develop new techniques ranging in scope from biophysics to molecular biology, gather ideas to incorporate into new courses or labs, earn professional development points, and introduce them to UR faculty that can serve as future mentors. It will also involve high school students in summer research, which will allow them to develop critical thinking and problem solving skills, as well as to expose them to the excitement of science.