MOLECULAR MECHANISMS OF N TYPE CALCIUM CHANNEL MODULATIO

N型钙通道调节的分子机制

• 批准号: 2655036
• 负责人: Stephen R Ikeda
• 金额: $ 28.88万
• 依托单位: GUTHRIE FOUNDATION FOR EDUCATION AND RES
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-02-01 至 2002-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2655036
• 关键词: G protein; calcium channel; complementary DNA; laboratory rat; molecular cloning; neural transmission; nucleic acid sequence; oligonucleotides; receptor coupling; site directed mutagenesis; superior cervical ganglion; synapses; tissue /cell culture; voltage /patch clamp; voltage gated channel

Voltage-gated Ca2plus channels of the N-type are modulated via a number of discrete signaling pathways. The most commonly utilized pathway involves a membrane-delimited mechanism whereby receptor activation of a pertussis toxin-sensitive heterotrimeric G protein results in a distinct form of voltage-dependent inhibition. Despite intense investigation, the molecular mechanism underlying this signal transduction pathway is at present unknown. Thus, the long term goal of our research is to further our understanding of the molecular mechanisms underlying modulation of N-type Ca2plus channels. The main hypothesis to be tested is that neurotransmitter modulation of N-type Ca2plus channels is mediated by specific G-protein beta gamma-subunits which bind directly to a site on the Ca2plus channel photo1B-subunit to produce voltage- dependent channel inhibition. A combination of electrophysiological, molecular biological, and biochemical methods will be used to investigate modulation of both native and heterologously expressed N- type Ca2plus channels. Accordingly, the SPECIFIC AIMS are: 1) to identify the G protein subunit, i.e., Gphoto or G beta gamma, which mediates voltage-dependent N-type Ca2plus channel modulation; 2) to determine whether G protein subunit composition confers specificity in regard to voltage-dependent N-type Ca2plus channel modulation and receptor coupling; 3) to determine the site on the Ca2plus channel involved in G beta gamma subunit binding. These experiments will generate new information regarding the molecular mechanism of voltage-dependent N-type Ca2plus channel inhibition. The elucidation of this mechanism has broad implications as numerous G protein-coupled receptors, any of which are implicated in disease or are targets of therapeutics agents, are thought to modulate synaptic transmission in the peripheral and central nervous system, at least in part, via this mechanism.

N型的电压门控Ca2plus通道通过数字调制 离散信号通路。 最常用的途径 涉及一种膜限制的机制，从而受体激活 百日咳毒素敏感的异三聚体G蛋白导致独特的 电压依赖性抑制的形式。 尽管进行了激烈的调查， 该信号转导途径的基础分子机制为 目前未知。 因此，我们研究的长期目标是 进一步我们对基于分子机制的理解 N型Ca2plus通道的调节。 要测试的主要假设 是N型Ca2plus通道的神经递质调制是 由特定的G蛋白βγ-套件介导的，直接结合 到Ca2plus通道Photo1b-Subunit上的站点以产生电压 - 依赖通道抑制。 电生理学的组合， 分子生物学和生化方法将用于 研究天然和异源表达的N-的调节 键入CA2PLUS通道。 因此，具体目的是： 1）确定G蛋白亚基，即Gphoto或G beta伽玛， 介导依赖电压的N型Ca2plus通道调制； 2）确定G蛋白亚基成分是否赋予 关于电压依赖性n型Ca2plus通道的特异性 调节和受体耦合； 3）确定与G Beta伽马相关的Ca2plus通道上的位置 亚基结合。 这些实验将生成有关分子的新信息 电压依赖性N型Ca2plus通道的机理。 这 阐明这种机制具有广泛的含义，因为 蛋白质偶联受体，其中任何与疾病有关或 人们认为治疗剂的靶标可以调节突触 至少在外周和中枢神经系统中的传播 部分，通过这种机制。