Modulation of neuronal ion channels by 2nd messengers

第二信使对神经元离子通道的调节

• 批准号: 6898239
• 负责人: MARK S SHAPIRO
• 金额: $ 27.74万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6898239
• 关键词: Animalia; G protein; calcium channel; calcium flux; cell line; electrophysiology; guanosinetriphosphatases; intermolecular interaction; molecular site; neural transmission; neurons; neuroregulation; potassium channel; protein reconstitution; protein structure function; protein tyrosine kinase; second messengers; site directed mutagenesis; voltage /patch clamp; yeast two hybrid system

DESCRIPTION (provided by applicant): Ion channel currents represent the fundamental units of electrical activity in most organisms. In our nervous system, K+ and Ca2+ ion channels play critical roles, and the modulation of their activity provides a way to directly control cellular excitability and release of neurotransmitters at synapses. The regulatory pathways are crucial to basic nervous function and their understanding should contribute to novel modes of medical interventions for a range of disorders involving the brain, nerves and muscles. We focus primarily on an important family of K+ channels called KCNQ that underlies the neuronal M current and secondarily, on high threshold, N-type Ca2+ channels. In particular, we seek to elucidate the molecular mechanisms of several modulatory pathways that act on these two types of ion channels. Several different neurotransmitters, acting via specific receptors and a ubiquitous family of signaling proteins called G proteins, modulate these channels via two distinct modes of action. Both types of signals use cytoplasmic messengers, but many of the intracellular signaling molecules they use remain unidentified, and their mechanisms of action undetermined. Another mode of modulation that acts on ion channels involves tyrosine kinases and small, monomeric GTPases. We will use the tools of patch-clamp electrophysiology, molecular biology, optical imaging, and biochemistry to investigate 1) what molecules are involved in each signal, 2) where is their site of action on the channel proteins and 3) how these signaling pathways interact with each other. Two general types of in vitro systems will be used: a heterologous expression system in which signaling is reconstituted using cloned components, and a preparation of primary sympathetic neurons. We hypothesize that each signal uses distinct sets of signaling molecules that confer specificity of action, that intracellular 2nd about-messengers act on ion channels at particular sites on the channels, and that multiple signaling pathways act in concert to provide nerve cells a broad array of regulatory options. We expect that this study will help understand how the billions of cells of the nervous system orchestrate the complex phenomena of human thought, emotion and behavior, and that our findings will help to alleviate the many diseases of mood, motion and consciousness that are disorders of nervous function.

描述（由申请人提供）：离子通道电流代表 大多数生物体中电活动的基本单位。在我们紧张的 系统中，K+ 和 Ca2+ 离子通道起着关键作用，并且调节 它们的活性提供了一种直接控制细胞兴奋性的方法 突触释放神经递质。监管途径至关重要 基本神经功能及其理解应有助于新颖的 针对一系列涉及大脑的疾病的医疗干预模式， 神经和肌肉。我们主要关注重要的 K+ 频道系列 称为 KCNQ，它是神经元 M 电流的基础，其次是高 阈值，N 型 Ca2+ 通道。我们特别试图阐明 作用于这两种类型的几种调节途径的分子机制 离子通道。几种不同的神经递质，通过特定的作用 受体和一个普遍存在的信号蛋白家族，称为 G 蛋白， 通过两种不同的作用模式调节这些通道。两种类型的信号 使用细胞质信使，但许多细胞内信号分子 它们的用途仍未确定，其作用机制也未确定。 另一种作用于离子通道的调节模式涉及酪氨酸激酶 和小单体 GTP 酶。我们将使用膜片钳工具 电生理学、分子生物学、光学成像和生物化学 研究 1) 每个信号涉及哪些分子，2) 它们在哪里 通道蛋白的作用位点以及 3) 这些信号传导途径如何 彼此互动。将使用两种一般类型的体外系统： 异源表达系统，其中使用克隆的信号重建 成分和初级交感神经元的制剂。我们假设 每个信号都使用不同的信号分子组，这些分子赋予 作用的特异性，细胞内第二信使作用于离子 信道上特定站点的信道，并且多个信令 通路协同作用，为神经细胞提供广泛的调节 选项。我们期望这项研究将有助于了解数十亿 神经系统的细胞协调人类思想的复杂现象， 情绪和行为，我们的发现将有助于缓解许多 情绪、运动和意识疾病，属于神经障碍 功能。