CHLORIDE TRANSPORT IN NERVE AND MUSCLE

这是一个研究两种不同氯离子转运机制的建议; 这两种蛋白似乎都广泛分布在动物细胞中。 一 机制使用C1，Na和HCO 3的运动来挤出或中和 细胞内酸性。 在本建议书中，我们将研究这一制度是如何 酸性细胞内pH值激活，以及它如何从一个明显的 C1/C1交换机制为更复杂的Na和HCP 3依赖性酸 挤出机 我们的中心假设是ATP依赖的磷酸化 在这些事件中起着关键作用。 我们将对离子进行详细的研究 运输，以获得有关该运输的定量动力学信息 机制 第二个要研究的氯离子迁移机制是 钠钾氯协同转运蛋白。 这种转运蛋白也需要ATP， 大概不是因为能量或热力学的原因。 我们认为 磷酸化也参与调节活性， 传送器 在这两种运输机中，我们将研究基本运输 刺激和/或抑制剂的性质以及作用 蛋白激酶和蛋白磷酸酶，以证实我们的 通过蛋白磷酸化转运活化假说。 这些研究将在巨细胞（鱿鱼巨轴突和 藤壶巨肌纤维）。 它们的大尺寸使我们能够使用 控制细胞内和细胞外的细胞内透析技术 内容. 该方法允许测量单向离子通量 通过这些氯化物运输机制，我们将使用 放射性同位素标记的配体，以尝试标记和部分 确定参与运输过程的膜蛋白。

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.