BASOLATERAL MEMBRANE POTASSIUM CHANNELS

描述：本建议是为了继续正在进行的研究， PI多年来一直在研究基底外侧钾通道。 这些 基底外侧钾通道已被证明是重要的上皮细胞 钠吸收 PI已经确定了ATP调节的钾通道 存在于钠吸收上皮细胞的基底外侧膜中 这可能是造成 钠-钾泵活性和钾传导性 膜的 目前的研究主要集中在钾离子通道， 蝾螈的小肠细胞，斑点蝾螈。 的 申请分两个阶段进行， 同时：第一阶段包括生理和电生理 渠道的研究，而第二阶段包括克隆， 确定其结构-功能关系。 实验 方法将包括研究基底外侧的单通道活动， 膜囊泡和经典的微生理技术。 他的第一 目的探讨ATP、ADP及ATP/ADP比值对心肌细胞凋亡的影响 以及确定信道活动是否 受到细胞内信号的影响， 由蛋白激酶介导的磷酸化/去磷酸化和/或 磷酸酶 第二个具体目标是进一步测试他们的 K（ATP）通道的“电压门控”模型，具体参考 磺酰脲衍生物和“通道”的作用机制 “开松剂”如二氮嗪。 第三个具体目标将使用常规 电生理方法来确定K（ATP） 通道有助于总基底外侧膜电导的 完整的肠上皮细胞和宏观泵泄漏平行性。 最后一 具体目标将是克隆K（ATP）通道，确定其 一级和推定的二级结构，并启动研究，以确定 它的结构-功能关系。 这些研究当然很重要 在我们对钾离子通道相关的基础生理学的理解中， 它们在钠吸收上皮细胞中的作用。

DESCRIPTION: This proposal is for continuation of ongoing studies on basolateral potassium channels investigated by the PI for many years. These basolateral potassium channels have been shown to be important in epithelial sodium absorption. The PI has identified ATP-regulated potassium channels present in the basolateral membrane of sodium-absorbing epithelial cells that may be responsible for the parallelism between the rate of sodium-potassium pump activity and the potassium conductance of the membrane. The current studies are focused on the potassium channels from the small intestinal cells of the salamander, Necturus maculosa. The application is divided into two phases which will be conducted simultaneously: first phase includes physiological and electrophysiological studies of the channels, while the second phase includes cloning and determining its structure-function relationships. The experimental approaches will include studies of single channel activity in basolateral membrane vesicles and classical microphysiological techniques. His first specific aim is designed to explore the effects of ATP, ADP and the ATP/ADP ratio on channel activity as well as to determine whether channel activity is affected by intracellular signals including phosphorylation/dephosphorylation mediated by protein kinases and/or phosphatases. The second specific aim focuses on testing further their model for "voltage gating" of the K(ATP) channels with specific reference to the mechanisms of action of the sulfonylurea derivatives and the "channel openers" such as diazoxide. The third specific aim will use conventional electrophysiological approaches to determine the extent to which the K(ATP) channels contribute to the total basolateral membrane conductance of the intact enterocyte and to the macroscopic pump-leak parallelism. The last specific aim will be directed at cloning the K(ATP) channel, determining its primary and putative secondary structure and initiating studies to determine its structure-function relationships. These studies are certainly important in our understanding of basic physiology related to potassium channels and their role in sodium absorbing epithelia.