GENETIC CONTROL OF MEMBRANE CURRENTS

膜电流的遗传控制

• 批准号: 3396176
• 负责人: WILLIAM L. BYERLEY
• 金额: $ 10.69万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-07-01 至 1988-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3396176
• 关键词: calcium channel blockers; cations; cell membrane; cell transformation; electrophysiology; ganglions; genetic regulation; ion transport; membrane permeability; membrane potentials; membrane structure; microelectrodes; muscle cells; mutant; phosphorylation; temperature sensitive mutant; tissue /cell culture

The long-term goal of this project is to determine the mechanisms by which the genome determines the membranc currents of excitable cells. All studies are electrophysiological, employing suction-electrode voltage-clamp techniques (often referred to as "patch clamp" techniques when the electrode opening is less than 2Mum) that allow a higly detailed analysis of the electrical properties of the membrane. Three approaches will be followed. The first approach is a search for mechanisms of control. The sensitivity of snail (Lymnaea) neuron membrane currents to intracellular messengers will be analyzed in isolated patches of membrane. In particular, an examination will be made of the apparent roles of intracellular Ca2+ and H+ to block Ca current and to activate K and non-specific currents. The role of intracellular phosphorylation in controlling both Ca and K currents will be investigated. The size of single-channel proton currents will be determined. The second approach focuses on the dynamic aspect of genome control. The changes in membrane excitability that occur in cultured adult snail (Helisoma) neurons and developing embryonic Drosophila nerve and muscle cells will be studied. These studies will determine the stability of differentiated membranes after isolation, the time course with which the undifferentiated membrane gains its excitability, and the somal membrane currents associated with neurite growth. The third approach will dissect the elements of genetic control of membrane excitability by characterizing the changes in membrane currents that result from mutations. Patch clamp studies will be made on Drosophila nerve and muscle cells in embryo cultures made from the eggs of mutant flies. Behavioral mutants for which there is considerable evidence of a membrane defect, e.g. Shaker and Nap, will be examined first. Due to the importance of intracellular Ca2+ in controlling transmitter release, muscle contraction, and other cellular functions, primary attention will be given to the Ca current and overlapping K currents, which determine the influx of Ca2+ into the cell. Mechanisms discovered or elucidated by this project will contribute significantly to the understanding of neural and muscular diseases that involve altered states of membrane excitability or synaptic efficacy.

该项目的长期目标是确定 基因组决定了可激发细胞的膜电流。 全部 研究是电生理学的，采用抽吸 - 电压电压钳 技术（通常称为“补丁夹”技术时 电极开口小于2MUM），可以进行详细的分析 膜的电性能。 三种方法将是 紧随其后。 第一种方法是搜索控制机制。 灵敏度 蜗牛（lymnaea）神经元膜电流到细胞内信使 将在隔离的膜斑块中进行分析。 特别是 检查将对细胞内Ca2+和H+的明显作用进行检查 阻止CA电流并激活K和非特异性电流。 角色 控制Ca和K电流的细胞内磷酸化 被调查。 单通道质子电流的大小将 决定。 第二种方法着重于基因组控制的动态方面。 这 成人蜗牛中发生的膜兴奋性的变化 （Helisoma）神经元并发展出胚胎果蝇神经和肌肉 细胞将被研究。 这些研究将决定 隔离后分化的膜，与之相关的时间过程 未分化的膜获得了兴奋性，膜膜 与神经突生长相关的电流。 第三种方法将剖析膜遗传控制的元素 通过表征导致膜电流的变化来兴奋性 从突变。 斑块夹研究将对果蝇神经和 由突变蝇卵制成的胚胎培养物中的肌肉细胞。 有大量证据表明膜的行为突变体 缺陷，例如摇床和午睡，将首先检查。 由于细胞内Ca2+在控制发射机中的重要性 释放，肌肉收缩和其他细胞功能，主要 将注意CA电流和重叠K电流的注意 确定Ca2+进入细胞的流入。 发现的机制或 该项目阐明将对 了解涉及改变状态的神经和肌肉疾病 膜兴奋性或突触功效。