CHLORIDE TRANSPORT IN NERVE AND MUSCLE

神经和肌肉中的氯离子转运

• 批准号: 3394667
• 负责人: JOHN M RUSSELL
• 金额: $ 29.02万
• 依托单位: ALLEGHENY UNIVERSITY OF HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-09-01 至 1995-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3394667
• 关键词: Cephalopoda; Cirripedia; acidity /alkalinity; adenosinetriphosphatase; axon; carbonates; chlorine; ligands; membrane permeability; membrane proteins; membrane transport proteins; microelectrodes; muscle cells; phosphoprotein phosphatase; phosphorus; phosphorylation; potassium; protein kinase; radionuclides; radiotracer; saltwater environment; sodium; stoichiometry

This is a proposal to study two different chloride transport mechanisms; both of which appear to be widely distributed in animal cells. One mechanism uses movements of C1, Na and HCO3 to extrude or neutralize intracellular acidity. In this proposal we will examine how this system is activated by acidic intracellular pH and how it changes from an apparent C1/C1 exchange mechanism to a more complicated Na and HCP3 - dependent acid extruder. Our central hypothesis is that ATP-dependent phosphorylation plays a key role in these events. We will perform detailed studies of ion transport to obtain quantitative kinetic information about this transport mechanism. The second chloride transport mechanism to be studied is the Na, K, Cl co-transporter. This transporter also requires ATP but presumably not for energetic or thermodynamic reasons. We believe phosphorylation is also involved for the regulation of activity by this transporter. In both transporters we will study fundamental transport properties as well as the effects of agents to stimulate and/or inhibit protein kinases and protein phosphatases in an effort to substantiate our hypothesis of transport activation via protein phosphorylation. These studies will be conducted on giant cells (squid giant axon and barnacle giant muscle fibers). Their large size allows us to use the technique of intracellular dialysis to control both intra-and extracellular contents. The method permits the measurement of unidirectional ion fluxes by these chloride transport mechanisms, we will use radioactive-isotope-labelled ligands to attempt to label and partially identify the membrane protein(s) involved in the transport processes.

这是研究两种不同的氯离子传输机制的提案； 两者似乎广泛分布于动物细胞中。 一 机制利用 C1、Na 和 HCO3 的运动来挤出或中和 细胞内酸度。 在这个提案中，我们将研究这个系统是如何运作的 被酸性细胞内 pH 激活以及它如何从表观 pH 变化 C1/C1 交换机制为更复杂的 Na 和 HCP3 依赖的酸 挤出机。 我们的中心假设是 ATP 依赖性磷酸化 在这些事件中发挥着关键作用。 我们将对离子进行详细研究 运输以获得有关该运输的定量动力学信息 机制。 要研究的第二个氯离子传输机制是 Na、K、Cl 协同转运蛋白。 该转运蛋白也需要 ATP，但是 大概不是出于能量或热力学原因。 我们相信 磷酸化也参与了这种活性的调节 运输者。 在这两个运输机中，我们将研究基本运输 特性以及刺激和/或抑制剂的作用 蛋白激酶和蛋白磷酸酶，以努力证实我们的 通过蛋白质磷酸化激活转运的假设。 这些研究将在巨细胞（鱿鱼巨轴突和 藤壶巨型肌纤维）。 它们的大尺寸使我们能够使用 细胞内透析技术可同时控制细胞内和细胞外 内容。 该方法允许测量单向离子通量 通过这些氯离子传输机制，我们将使用 放射性同位素标记的配体尝试标记并部分 识别参与运输过程的膜蛋白。