FUNCTION AND REGULATION OF POLYCYSTIN-2

本项目研究了多囊蛋白2（PC2）作为细胞内钙通道的特性。在本项目中，将测试两类潜在的调节器，其中每个调节器是复合体或级联的一部分。将测试破坏对细胞内钙信号传导和随后的下游信号传导的调节的后果。从这些实验中获得的结果将确定调节PC2活性的调节因子，将概述这些相互作用的分子基础以及它们是如何被调节的，并将提出siganling级联的下游靶点。待检验的假设是：1）PC 1和PC 2之间的相互作用是功能性的，并且可以从PC 2的分子特性预测。2)PC 2和Ryanodine受体（RyR）形成通道复合物，其中PC 2调节RyR的活性，然后RyR可以调节整体细胞内钙 信号3)通道复合物调节的变化将改变细胞内钙信号传导和完整细胞中的下游信号传导。这些变化将对完整动物的器官产生影响。这里提出的初步结果表明，PC 2有几个蛋白质的合作伙伴，这些相关的蛋白质是重要的调节通道复合物。本项目中概述的实验将在单通道水平上研究PC2的功能特性，并将通道特性与细胞和器官功能相关联。获得的结果可能会在分子水平上确定PC2的作用机制，并可能为多囊肾患者提供有用的治疗方法。

This project examines the properties of polycystin-2 (PC2) as an intracellular calcium channel. In this project two classes of potential regulators will be tested where each regulator is part of the complex or cascade. The consequences of disrupting the regulation on the intracellular calcium signaling and on the subsequent downstream signaling will be tested. The results obtained from these experiments will identify regulatory factors that modulate the activity of PC2, will outline the molecular basis for these interactions and how they are regulated, and will suggest downstream targets for the siganling cascade. The hypotheses to be tested are: 1) The interactions between PC1 and PC2 are functional and can be predicted from the molecular properties of PC2. 2) PC2 and the ryanodine receptor (RyR) make a channel complex where PC2 regulates the activity of the RyR which then can modulate global intracellular calcium signaling. 3) Changes in the regulation of the channel complex will modify intracellular calcium signaling, and downstream signaling in intact cell. These changes will have consequences on organs in the intact animal. The preliminary results presented here show that PC2 has several protein partners and that these associated proteins are important for regulating the channel complex. The experiments outlined in this project will investigate the functional properties of PC2 at the single channel level and will correlate the channel properties with cell and organ function. The results to be obtained may determine the mechanism of action of PC2 at a molecular level and may suggest useful treatments for individuals affected with polycystic kidney disease.