DYNAMIC ORGANIZATION OF THE RENAL CELL MEMBRANE SKELETON IN VIVO

产品描述：肾上皮细胞载体转运功能的核心是上皮细胞表面膜蛋白的极化分布。最近的证据表明，血影蛋白为基础的皮层细胞骨架，与许多完整的膜蛋白，也是高度极化，并可能发挥根本性的作用，在维持和指导地形膜组装。最近的证据还表明，一个独立的但相关的高尔基血影蛋白骨架（SAATS）调节某些膜蛋白，如Na，K-ATP酶的组装和运输。拟议的研究的总体目标将是了解皮质和囊泡细胞骨架如何实现其极化分布，以及这个过程的关系，基底外侧的整合膜蛋白Na，K-ATP酶和E-cadherin的排序。具体来说，研究将集中在如何干扰的因素，目标血影蛋白的肾上皮细胞的侧缘调节其与其他完整的膜蛋白，如E-钙粘蛋白和Na，K-ATP酶的相互作用，以及这些过程如何影响在体内肾脏的发展，功能，和肾脏的病理应激反应。待检测的特异性蛋白质包括β 1、β II和β III血影蛋白，锚蛋白的几种亚型，包括与囊泡高尔基体血影蛋白骨架相关的那些（AnkG 119），以及与细胞核相关的锚蛋白的一种形式。还感兴趣的是选择的衔接蛋白，包括α和β-连环蛋白。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，它们在体内的作用通过构建具有特定细胞骨架突变的转基因和基因敲除/敲入小鼠来测量。在与该计划项目组的其他成员的合作，血影蛋白为基础的组装途径与上皮和内皮细胞肌动蛋白细胞骨架和粘附复合物的其他组件的交叉点也将进行探索。作为新的监管级联涉及血影蛋白锚蛋白皮质和囊泡细胞骨架被确定，这些级联在体内介导急性肾损伤的作用将被探讨。预计这些研究将指导我们寻找膜细胞骨架功能障碍起病因作用的肾脏疾病，并将有助于设计合理的临床反应，伴随急性肾缺氧和缺氧损伤的细胞事件。

Description: (Abstract of the project) 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, associated with many integral membrane proteins, is also highly polarized and may play a fundamental role in maintaining and guiding topographic membrane assembly. Recent evidence also indicates that a separate but related Golgi spectrin skeleton (SAATS) modulates the assembly and trafficking of certain membrane proteins such as Na,K-ATPase. The overall goal of the proposed studies will be to understand how the cortical and vesicular cytoskeletons achieve their polarized distribution, and the relationship of this process to the sorting of the basolateral integral membrane proteins Na,K-ATPase and E-cadherin. Specifically, research will focus on how perturbation of the factors that target spectrin to the lateral margins of kidney epithelial cells regulate its interactions with other integral membrane proteins such as E-cadherin and Na,K-ATPase, and how these processes affect in vivo renal development, function, and the response of the kidney to pathologic stress. Specific proteins to be examined include beta 1, beta II, and beta III spectrin, several isoforms of ankyrin including those associated with the vesicular Golgi spectrin skeleton (AnkG119), and a form of ankyrin associated with the nucleus. Also of interest are selected adapter proteins including alpha and beta-catenin. The interaction between these proteins will be measured by sensitive genetic and biochemical assays, and their role in vivo gauged by constructing transgenic and gene knock-out/knock-in mice with specific cytoskeletal mutations. In collaboration with other members of the program project team, the intersection of the spectrin based assembly pathways with other components of the epithelial and endothelial cell actin cytoskeleton and adhesion complexes will also be explored. As novel regulatory cascades involving the spectrin-ankyrin cortical and vesicular cytoskeletons are identified, the role of these cascades in mediating acute renal injury in vivo will be explored. It is anticipated that these studies will guide our search for renal diseases in which membrane cytoskeletal dysfunction plays an etiologic role, and will aid in designing rationale clinical responses to the cellular events that accompany acute renal hypoxic and anoxic injury.