CHLORIDE TRANSPORT IN NERVE AND MUSCLE

这是一个研究两种不同氯离子转运的建议 这两种机制似乎都广泛分布在 动物细胞 一种机制使用C1、Na和 HCO3来挤出或中和细胞内的酸性。 在这 我们将研究这个系统是如何被酸性激活的。 细胞内pH值以及它如何从表观C1/C1 更复杂的Na和HCP3-交换机制 非独立酸挤出机。 我们的核心假设是ATP- 依赖性磷酸化在这些事件中起关键作用。 我们 将对离子传输进行详细的研究， 关于这种运输机制的定量动力学信息。 第二个要研究的氯离子传输机制是Na， K、C1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 相信磷酸化也参与了调节 该运输商的活动。 在这两种转运体中，我们将研究 基本的传输特性以及代理商的影响 以刺激和/或抑制蛋白激酶和蛋白质 磷酸酶，以证实我们的假设， 通过蛋白质磷酸化激活转运。 这些研究将在巨细胞（鱿鱼巨轴突）上进行 和藤壶巨肌纤维）。 它们的巨大体型使我们能够 利用细胞内透析技术， 和细胞外内容物 该方法允许测量 这些氯离子的运输 机制，我们将使用放射性同位素标记的配体， 尝试标记和部分鉴定膜蛋白 参与运输过程。

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, C1 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.