Regulation of epithelial cell motility by villin.

绒毛蛋白对上皮细胞运动的调节。

• 批准号: 7034645
• 负责人: Seema Khurana
• 金额: $ 32.08万
• 依托单位: UNIVERSITY OF TENNESSEE HEALTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7034645
• 关键词: actin binding protein; actins; binding sites; biological signal transduction; cell migration; cell morphology; cell motility; chemical kinetics; cytoskeleton; epithelium; gastrointestinal epithelium; gene expression; genetically modified animals; laboratory mouse; microfilaments; molecular assembly /self assembly; phosphatidylinositols; phospholipase C; protein protein interaction; protein structure function; recombinant proteins; tissue /cell culture

DESCRIPTION (provided by applicant): The PI proposes to determine and characterize the role of villin and its ligands (phosphatidylinositol 4,5- bisphosphate (PIP2) and actin) in epithelial cell motility. Active cell motility regulates many important intestinal epithelial cell functions, including: ion transport proteins via endocytosis and exocytosis, crucial for absorption of nutrients; intestinal restitution, important to maintain homeostasis in the presence of large osmotic and mechanical stress; the movement of cells along the crypt-villus axis; the invasion and propagation of enteropathogens; immune surveillance and inflammation; as well as neoplastic tumor cell dissemination and metastasis. Villin is an actin nucleating, capping, severing, and bundling protein. Villin binds and regulates two ligands that are known to regulate cell motility, phospholipase C-gamma1 (PLC-gamma1) as well as the substrate of the lipase namely, phosphatidylinositol 4,5-bisphosphate (PIP2). Recent studies with villin knock out mice have demonstrated that villin is necessary to regulate epithelial cell motility. In addition, villin shares sequence homology with other proteins of its family including gelsolin, which have been shown to regulate cell motility in vivo. Our working hypothesis is that villin's ability to regulate phosphoinositide-mediated signal transduction pathways and the actin cytoskeleton is important to epithelial cell physiology and pathophysiology involving changes in cell motility. To accomplish our overall study objectives we will characterize the villin-PIP2 interaction using the following approaches: reconstitution in vitro using recombinant villin proteins; endogenous villin expression in the intestinal epithelial cell line, Caco-2; and over expression of villin and enzymes that regulate intracellular PIP2 levels, in the villin null intestinal cell line, IEC-6 using a tetracycline-regulated system. To determine unequivocally the role of villin in the epithelial cell motility, we will use villin knock out mice. These studies promise the prospect of modifying motility for enhancement of normal physiology and for amelioration of disease. Inhibition of epithelial cell motility can be significant in several diseases, including inflammatory bowel disease, celiac disease, and colon cancer.

描述（由申请人提供）：PI 提议确定和表征绒毛蛋白及其配体（磷脂酰肌醇 4,5-二磷酸 (PIP2) 和肌动蛋白）在上皮细胞运动中的作用。 活跃的细胞运动调节许多重要的肠上皮细胞功能，包括： 通过胞吞作用和胞吐作用的离子转运蛋白，这对营养物质的吸收至关重要；肠道恢复，对于在存在大渗透压和机械应力的情况下维持体内平衡很重要；细胞沿着隐窝-绒毛轴的运动；肠道病原体的入侵和繁殖；免疫监视和炎症；以及肿瘤细胞的播散和转移。绒毛蛋白是一种肌动蛋白，具有成核、加帽、切断和捆绑作用。 Villin 结合并调节已知可调节细胞运动的两个配体：磷脂酶 C-gamma1 (PLC-gamma1) 以及脂肪酶的底物，即磷脂酰肌醇 4,5-二磷酸 (PIP2)。 最近对绒毛蛋白敲除小鼠的研究表明，绒毛蛋白对于调节上皮细胞运动是必需的。 此外，绒毛蛋白与其家族的其他蛋白质（包括凝溶胶蛋白）具有序列同源性，凝溶胶蛋白已被证明可以调节体内细胞运动。 我们的工作假设是，绒毛调节磷酸肌醇介导的信号转导途径和肌动蛋白细胞骨架的能力对于涉及细胞运动变化的上皮细胞生理学和病理生理学很重要。 为了实现我们的总体研究目标，我们将使用以下方法表征绒毛蛋白-PIP2 相互作用：使用重组绒毛蛋白在体外重建；肠上皮细胞系 Caco-2 中内源绒毛蛋白的表达；使用四环素调节系统，在绒毛无效肠细胞系 IEC-6 中过度表达绒毛和调节细胞内 PIP2 水平的酶。 为了明确确定绒毛蛋白在上皮细胞运动中的作用，我们将使用绒毛蛋白敲除小鼠。 这些研究有望通过改变运动来增强正常生理机能和改善疾病。 上皮细胞运动的抑制在多种疾病中可能具有重要意义，包括炎症性肠病、乳糜泻和结肠癌。