Synaptic Glutamate Receptor Trafficking

描述(申请人提供)：我的研究计划的总体目标是阐明支配突触后突触组件组装的潜在分子原理。我们希望解决三个主要问题。首先，在突触形成过程中发生的一系列事件是什么？第二，突触如何保持稳定的解剖学特性？最后，活动导致突触功能改变的机制是什么？了解突触传递的核心是嵌入突触后密度(PSD)的谷氨酸受体。为了实现这些雄心勃勃的目标，我们使用了多种技术的组合。我们的研究最核心的是电生理学，因为这是衡量我们分子操作的功能后果的最关键的方法。这项拨款的重点是作为谷氨酸受体辅助亚单位的各种蛋白质。虽然人们早就知道电压门控离子通道上有辅助亚基，它们控制着运输和功能的方方面面，但有关配体门控离子通道也与辅助亚基相关的通知是相当新的。研究最多的辅助亚基家族是TARPS，它选择性地控制AMPAR亚型谷氨酸受体的运输和功能。然而，最近的研究表明，其他结构无关的蛋白质，如CNIH2、CKAMP44和SynDIG1也可以作为AMPAR的辅助亚基。此外，Neto-1/2已被证明对红藻氨酸受体具有类似的作用。在这次更新中，我们将通过使用CNIH2来表征其在大脑中的角色 条件性基因敲除小鼠。初步结果表明，删除CNIH2会产生广泛的影响。我们还将确定TARP？-7的生理作用，这是一种不寻常的TARP，使其有别于其他特性良好的TARP。了解SynDIG1的作用构成了这项赠款的第三个目标。这些实验将同时使用切片培养中的过表达和RNAi。最后，我们将使用通常缺乏海人酸受体的CA1突触作为空，以确定Neto-1/2在海人酸受体的运输和门控中的作用。人们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。鉴于受体转运在突触可塑性中的关键作用，预计这些研究的结果将产生直接的临床影响。事实上，临床上有希望的Ampakines发挥其作用，部分是通过控制AMPAR门控的动力学，类似于Tarp。

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.