Regulation of Synaptic Transmission by Gq

Gq 对突触传递的调节

• 批准号: 7575282
• 负责人: Michael Ailion
• 金额: $ 7.5万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7575282
• 关键词: Accounting; Affect; Animals; Attention deficit hyperactivity disorder; Behavior Disorders; Behavioral; Binding; Biochemical; Biological Assay; Brain; Caenorhabditis elegans; Candidate Disease Gene; Cells; Chemicals; Communication; Disease; Docking; Electron Microscopy; Electrophysiology (science); GTP-Binding Proteins; Genes; Genetic; Genetic Screening; Goals; Grant; Guanine Nucleotide Exchange Factors; Guanosine Triphosphate Phosphohydrolases; Heterotrimeric GTP-Binding Proteins; Human; In Vitro; Laboratories; Lead; Learning; Link; Measures; Mental Health; Mentally Ill Persons; Mentors; Methods; Molecular; Molecular Analysis; Monomeric GTP-Binding Proteins; Mutation; Nematoda; Nervous system structure; Neuromodulator; Organism; Pathway interactions; Pharmaceutical Preparations; Phase; Phenotype; Physiological; Physiology; Probability; Process; Regulation; Research; Research Personnel; Running; Schizophrenia; Signal Transduction; Site; Synapses; Synaptic Transmission; Synaptic Vesicles; Synaptic plasticity; Techniques; Tertiary Protein Structure; Tissues; Training; Vesicle; Work; brain cell; depression; design; mutant; nervous system disorder; neurotransmission; novel; pointed protein; programs; research study; trafficking

DESCRIPTION (provided by applicant): 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 application 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 application 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.

描述（由申请人提供）：拟议研究的长期目标是了解突触可塑性的分子机制。异三聚体 G 蛋白被认为是多种生物体中突触可塑性的调节因子，但它们调节突触强度的机制尚不清楚。本应用旨在表征 Gq 作为线虫突触传递的正调节因子的途径。对激活的 Gqa 突变体抑制因子的遗传筛选导致鉴定出作用于 Gqa 下游的途径的新组件，包括小 GTP 酶的鸟嘌呤核苷酸交换因子，以及假设充当效应子的新型 RUN 结构域蛋白一个小的 GTP 酶。目标 1 将鉴定小 GTP 酶并表征其与 Gqa 途径的相互作用，特别是确定小 GTP 酶和 RUN 结构域蛋白是否发生物理相互作用。遗传相互作用将通过对突变动物进行行为和药理学测定来确定。生化相互作用将通过使用 GST 下拉的体外结合测定来确定。目标 2 将确定 Gqa 和小 GTPase 通路调节突触释放的机制。电子显微镜和突触电生理学将用于表征改变的通路活性对囊泡对接/启动和囊泡释放概率的影响。学习这些技术是本次资助的指导阶段的主要培训目标。目标 3 和 4 将识别更多作用于 Gqa 下游的分子，并使用目标 1 和 2 的方法确定其作用机制。目标 1 和 2 将在指导阶段完成，目标 3 和 4 将在独立阶段完成。这些研究将是定义 Gq 调节突触强度作用的分子途径的重要一步。许多与人类行为障碍相关的神经调节剂通过 G 蛋白偶联途径发挥作用。了解这些神经调节剂的下游途径将有助于更好地了解这些疾病的机制，并有助于设计更好的药物治疗。由于这些途径是调节性的，而不是神经传递所必需的，因此这些途径发生突变的人类预计可以存活，但患有精神疾病。因此，这项工作中确定的新基因将是与人类心理健康疾病相关的基因的良好候选者。相关性：人类神经系统疾病，如精神分裂症、抑郁症和注意力缺陷/多动症，与影响不同脑细胞之间信号强度的大脑化学物质水平异常有关。该应用旨在了解这些化学物质如何影响神经系统细胞之间的通讯，以便设计出更好的药物来治疗这些疾病。