DYNAMIC ORGANIZATION OF THE RENAL CELL MEMBRANE SKELETON IN VIVO

肾上皮细胞载体转运功能的核心是 肾上皮细胞表面膜蛋白的极化分布 细胞 最近的证据表明，血影蛋白为基础的皮质 细胞骨架，这往往与某些完整的膜 蛋白质，也是高度极化的，并且可能在以下方面发挥重要作用： 维持和引导地形膜组件。 总目标 研究的重点是了解大脑皮层 细胞骨架实现其极化分布， 这个过程的排序basolatively限制积分 膜蛋白如Na，K-ATPase和E-cadherin。 具体地说， 研究将集中在如何扰动的因素，目标是 血影蛋白骨架向肾侧缘的组装 上皮细胞调节其与其他完整膜的相互作用 蛋白质如E-cadherin和Na，K-ATPase影响体内肾 发育、功能和肾脏对病理性 应力 待检测的特异性蛋白质包括红细胞样蛋白和 血影蛋白（fodrin）、锚蛋白、内收蛋白和 蛋白4.1、E-钙粘蛋白、α-连环蛋白以及 与肾血影蛋白相互作用。 这些蛋白质之间的相互作用 将通过敏感的遗传和生物化学测定来测量， 体内作用将通过构建具有特异性 细胞骨架突变 由于许多细胞骨架突变已经 在细胞培养模型中发现以显性负性方式起作用， 预计这些研究将指导我们寻找肾脏 膜细胞骨架功能障碍起病因作用的疾病 作用

Central to the vectorial transport function of renal epithelium is the polarized distribution of surface membrane proteins in renal epithelial cells. Recent evidence indicates that the spectrin based cortical cytoskeleton, which is often associated with certain integral membrane proteins, is also highly polarized, and may play a fundamental role in maintaining and guiding topographic membrane assembly. The overall goal of the proposed studies will be to understand how the cortical cytoskeleton achieves its polarized distribution, and the relationship of this process to the sorting of basolaterally restricted integral membrane proteins such as Na,K-ATPase and E-cadherin. Specifically, research will focus on how perturbation of the factors that target the assembly of the spectrin skeleton to the lateral margins of kidney epithelial cells regulate its interactions with other integral membrane proteins such as E-cadherin and Na,K-ATPase affect in vivo renal development, function, and the response of the kidney to pathologic stress. Specific proteins to be examined include the erythroid-like and non-erythroid isoforms of spectrin (fodrin), ankyrin, adducin, and protein 4.1, E-cadherin, alpha-catenin, as well as novel proteins that interact with renal spectrin. The interaction between these proteins will be measured by sensitive genetic and biochemical assays, and their role in vivo will be gauged by constructing transgenic mice with specific cytoskeletal mutations. Since many cytoskeletal mutations have been found in cell culture models to act in a dominant negative fashion, it is anticipated that these studies will guide our search for renal diseases in which membrane cytoskeletal dysfunction plays an etiologic role.