CHLORIDE TRANSPORT IN NERVE AND MUSCLE

这是一项研究两种不同氯化物传输的建议 机制；这两种机制似乎广泛分布在 动物细胞。一种机制使用了C1、Na和 HCO3可以挤出或中和细胞内的酸性。在这 我们将研究酸性物质是如何激活这个系统的 细胞内pH及其与表观的C1/C1的变化 更复杂的Na和HCP3-的交换机理 从属酸挤出机。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 将对离子传输进行详细研究，以获得 有关这一运输机制的定量动力学信息。 第二个要研究的氯迁移机制是Na， K，C_1共转运蛋白。这款传送器也需要ATP，但 大概不是因为能量或热力学方面的原因。我们 我认为磷酸化也参与了对 这辆运输车的活动。我们将在这两种运输机上进行研究 基本输运性质以及介质的影响 刺激和/或抑制蛋白激酶和蛋白质 为了证实我们的假说， 通过蛋白质磷酸化来运输激活。 这些研究将在巨细胞(鱿鱼巨轴突)上进行 和藤壶巨型肌肉纤维)。它们的巨大尺寸使我们能够 使用细胞内透析技术控制两种细胞内 和胞外内容物。该方法允许测量 通过这些氯化物传输的单向离子通量 机制，我们将使用放射性同位素标记的配体来 尝试标记和部分鉴定膜蛋白(S) 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.