Regulation of Synaptic Transmission by Gq

项目概要：本研究的长期目标是了解其分子机制 突触可塑性。异源三聚体G蛋白被认为是突触可塑性的调节因子， 各种生物，但它们调节突触强度的机制还不清楚。 该建议旨在描述Gq作为突触的正调节剂的途径， 线虫C.优雅一个激活的Gqa突变体的抑制基因的遗传筛选导致 鉴定Gqa下游作用途径的新组分，包括鸟嘌呤 一种小GT3的核苷酸交换因子，以及一种新的RUN结构域蛋白， 作为一个小GT3的效应器。目标1将识别小GTcycle并表征其 与Gqa途径的相互作用，特别是确定小GT3和RUN结构域是否 蛋白质物理相互作用。遗传相互作用将通过进行行为和 突变动物的药理学测定。生化相互作用将通过体外结合测定 使用GST下拉的测定。目标2将确定Gqa和小GTbu的机制。 通路调节突触释放。电子显微镜和突触电生理学将用于 表征改变的途径活性对囊泡对接/引发的影响以及囊泡对接/引发的可能性。 release.学习这些技术是该补助金指导阶段的主要培训目标。目标3和 4将鉴定更多作用于Gqa下游的分子，并使用 目标1和2的方法。目标1和2将在辅导阶段完成，目标3和4将在 独立阶段。这些研究将是确定Gq分子途径的重要一步 调节突触强度的作用。许多与人类行为障碍有关的神经调质 通过G蛋白偶联途径了解这些神经调质的下游通路 将导致更好地了解这些疾病的机制，并促进设计更好的 药物治疗因为这些通路是调节性的，而不是神经传递所必需的， 在这些途径中发生突变的人将被认为是可行的，但患有精神疾病。因此，新 在这项工作中确定的基因将是与人类精神健康疾病相关的基因的良好候选者。 相关性：精神分裂症、抑郁症和注意力缺陷等人类神经系统疾病/ 多动症与影响信号强度的大脑化学物质的异常水平有关 不同脑细胞之间的联系这项提案旨在了解此类化学物质如何影响交流 神经系统中细胞之间的相互作用，这样就可以设计出更好的药物来治疗这些疾病。

Project summary: The long-term goal of the proposed research is to understand the molecular mechanisms of synaptic plasticity. Heterotrimeric G proteins have been implicated as regulators of synaptic plasticity in various organisms, but the mechanisms by which they regulate synapse strength are not well understood. This proposal aims to characterize the pathways by which Gq acts as a positive regulator of synaptic transmission in the nematode C. elegans. A genetic screen for suppressors of an activated Gqa mutant led to the identification of new components of pathways acting downstream of Gqa, including a guanine nucleotide exchange factor for a small GTPase, and a novel RUN-domain protein that is hypothesized to function as an effector of a small GTPase. Aim 1 will identify the small GTPase and characterize its interactions with the Gqa pathway, in particular determining whether the small GTPase and the RUN-domain protein physically interact. Genetic interactions will be determined by performing behavioral and pharmacological assays of mutant animals. Biochemical interactions will be determined by in vitro binding assays using GST-pulldowns. Aim 2 will determine the mechanisms by which Gqa and the small GTPase pathway regulate synaptic release. Electron microscopy and synaptic electrophysiology will be used to characterize the effects of altered pathway activity on vesicle docking/priming and the probability of vesicle release. Learning these techniques is the major training goal of the mentored phase of this grant. Aims 3 and 4 will identify more molecules acting downstream of Gqa and determine their mechanisms of action using the methods of Aims 1 and 2. Aims 1 and 2 will be completed during the mentored phase, Aims 3 and 4 during the independent phase. These studies will be a major step forward in defining the molecular pathways of Gq action in modulating synaptic strength. Many neuromodulators linked to human behavioral disorders act through G protein-coupled pathways. Understanding the pathways downstream of these neuromodulators will lead to a better understanding of the mechanism of these diseases and facilitate the design of better drug treatments. Because these pathways are modulatory rather than essential for neurotransmission, humans with mutations in these pathways would be expected to be viable, but mentally ill. Thus, the new genes identified in this work will be good candidates for genes linked to mental health disease in humans. Relevance: Human nervous system disorders such as schizophrenia, depression and attention deficit/ hyperactivity disorder are linked to abnormal levels of brain chemicals that affect the strength of signaling between different brain cells. This proposal aims to understand how such chemicals affect communication between cells in the nervous system so that better drugs can be designed to treat these disorders.