BASOLATERAL MEMBRANE POTASSIUM CHANNELS

描述：这项建议是为了继续正在进行的研究 多年来，PI一直在研究基底外侧钾通道。这些 基底外侧钾通道在上皮细胞中起重要作用 钠的吸收。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膜 这可能是导致这一比率之间的平行 钠钾泵活性与钾电导的关系 薄膜。目前的研究主要集中在钾离子通道上。 斑点蜥蜴的小肠细胞。这个 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和 确定其结构-功能关系。实验性的 方法将包括研究基底外侧的单通道活动。 膜泡和经典的微生理学技术。他的第一次 具体目的是探讨三磷酸腺苷、三磷酸腺苷和三磷酸腺苷/三磷酸腺苷的作用。 关于通道活跃度的比率以及确定通道活跃度 受到细胞内信号的影响，包括 蛋白激酶和/或蛋白激酶介导的磷酸化/去磷酸化 磷酸酶。第二个具体目标集中在进一步测试他们的 K(ATP)通道的“电压门控”模型 磺酰脲衍生物与“通道”的作用机理 如二氮卓。第三个具体目标将使用常规 电生理方法确定K(ATP)的程度 通道对基底侧膜的总电导有贡献 完整的肠上皮细胞与宏观泵漏平行。最后 具体目标将是克隆K(ATP)通道，确定其 初级和推定的二级结构和启动研究以确定 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的基本生理学的理解中 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.