Synaptic Glutamate Receptor Trafficking

描述（由申请人提供）：我的研究计划的总体目标是阐明控制突触的突触后成分组装的基本分子原理。我们希望解决三个主要问题。首先，突触形成过程中发生的事件顺序是什么？第二，突触如何保持稳定的解剖学特性？最后，活动引起突触功能改变的机制是什么？理解突触传递的核心是嵌入突触后致密物（PSD）中的谷氨酸受体。为了实现这些雄心勃勃的目标，我们使用了许多技术的组合。我们研究的最核心是电生理学，因为这是衡量我们分子操作的功能后果的最关键方法。这项资助主要集中在作为谷氨酸受体辅助亚基的各种蛋白质上。虽然人们早就知道电压门控离子通道由辅助亚基装饰，辅助亚基控制运输和功能的各个方面，但配体门控离子通道也与辅助亚基结合的概念却是相当新的。研究最多的辅助亚基家族是TARPs，其选择性地控制谷氨酸受体的AMPAR亚型的运输和功能。然而，最近的研究表明，其他结构无关的蛋白质，如CNIH 2，CKAMP 44和SynDIG 1也作为AMPAR辅助亚基。此外，NETO-1/2已被证明对红藻氨酸受体起类似的作用。在这次更新中，我们将描述CNIH 2在大脑中的作用， 条件性基因敲除小鼠初步结果表明删除CNIH 2的广泛影响。我们还将确定TARP <$-7的生理作用，这是一种不寻常的TARP，它将其与其他具有良好特征的TARP区分开来。了解SynDIG 1的作用构成了本基金的第三个目标。切片培养物中的过表达和RNAi都将用于这些实验。最后，我们将使用CA 1突触，它通常缺乏红藻氨酸受体，作为一个空，以确定在运输和门控红藻氨酸受体的NETO-1/2的作用。希望这些研究将揭示谷氨酸辅助蛋白在神经系统中的新作用。考虑到受体运输在突触可塑性中的关键作用，预计这些研究的结果将具有直接的临床影响。实际上，临床上有前景的AMPAkine部分地通过控制类似于TARP的AMPAR门控的动力学来发挥其作用。

DESCRIPTION (provided by applicant): The overall goal of my research program is to elucidate the underlying molecular principles that govern the assembly of the postsynaptic component of a synapse. There are three main questions we wish to address. First, what are the sequences of events that occur during synapse formation? Second, how does a synapse maintain a stable anatomical identity? Finally, what is the mechanism whereby activity can induce a change in synapse function? Central to the understanding of synaptic transmission are the glutamate receptors embedded in the postsynaptic density (PSD). To tackle these ambitious goals we use a combination of a number of techniques. The most central to our studies is electrophysiology, since this is the most critical way to measure the functional consequences of our molecular manipulations. This grant is focused on a variety of proteins that act as glutamate receptor auxiliary subunits. While voltage gated ion channels have long been know to be decorated with auxiliary subunits, which control all aspects of trafficking and function, the notio that ligand gated ion channels also associate with auxiliary subunits is quite new. The most studied family of auxiliary subunits is the TARPs, which selectively control the trafficking and function of the AMPAR subtype of glutamate receptor. However, recent studies indicate that other structurally unrelated proteins, such as CNIH2, CKAMP44, and SynDIG1 also serve as AMPAR auxiliary subunits. In addition, NETO-1/2 has been shown to serve a similar role for kainate receptors. In this renewal we will characterize the role of CNIH2 in the brain with the use of conditional knockout mice. Initial results suggest widespread effects of deleting CNIH2. We will also determine the physiological role of TARP ¿-7, an unusual TARP, which sets it apart from the other well characterize TARPs. Understanding the role of SynDIG1 forms the third Aim of this grant. Both overexpression and RNAi in slice culture will be used for these experiments. Finally we will use the CA1 synapse, which normally lacks kainate receptors, as a null to determine the role of NETO-1/2 in trafficking and gating of kainate receptors. It is hoped that these studies will uncover novel roles for glutamate auxiliary proteins in the nervous system. Given the critical role that receptor trafficking plays in synaptic plasticity it is anticipated tht findings from these studies will have direct clinical impact. Indeed, clinically promising AMPAkines exert their effect, in part, by controlling the kinetics of AMPAR gating similar to TARPs.