CONTROL OF EPITHELIAL CELL MOTILITY BY E CADHERIN

E 钙粘蛋白对上皮细胞运动的控制

• 批准号: 2655867
• 负责人: ROBERT W BRACKENBURY
• 金额: $ 10万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-30 至 1998-04-09
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2655867
• 关键词: cadherins; cell motility; epithelium; genetically modified animals; laboratory mouse; wound healing

Cell-cell contacts mediated by the calcium-dependent adhesion molecule, E-cadherin, strongly affect the polarity and differentiation of epithelial cells. We have found that E-cadherin also suppresses the movement of epithelial cells. Strikingly, this suppression does not require adhesion mediated by E-cadherin, but instead appears to involve generation of an intracellular motility- suppressing signal. We have determined that part of the E- cadherin cytoplasmic segment, the juxtamembrane 9JM) region, is essential for generating this signal. Our overall goals are to identify the components of this signaling pathway, to determine which aspects of cell motility are suppressed by the signal, and to define the importance of this signal during epidermal development and wound-healing. To define the boundaries of the JM domains, we will analyze the effects on cell movement of JM deletion mutants and dominant-negative forms of the JM region. Components that interact with the JM domain will be identified by comparing the pattern of proteins co-immunoprecipitated with forms of E-cadherin that contain or lack this region, by affinity purification with JM domain fusion proteins, and by use of the yeast two-hybrid system. We will test whether these JM- associated components are involved in the signaling pathway by expressing dominant-negative polypeptides that will block their binding to the JM domain. We will test whether homophilic E- cadherin binding activates MAP kinase. To define cellular responses that may be regulated by this signal, we will determine whether E-cadherin affects membrane ruffling and filopodial extension. Finally, to determine the role of this regulation of motility during skin development and wound-healing, we will create and analyze transgenic mice in which dominant-negative forms of E-cadherin are expressed specifically in basal karatinocytes. Together, these studies will result in a better understanding of the mechanisms by which cell-cell contact regulates epithelial cell motility. Such knowledge will prove useful for enhancing wound healing and controlling carcinoma cell invasion.

由钙依赖性粘附介导的细胞与细胞接触 E-钙粘蛋白分子强烈影响极性和 上皮细胞的分化。 我们发现E-钙粘蛋白 还抑制上皮细胞的运动。 引人注目的是，这 抑制不需要 E-钙粘蛋白介导的粘附，但是 相反，似乎涉及细胞内运动的产生- 抑制信号。 我们已经确定了 E- 的一部分 钙粘蛋白细胞质片段，即近膜 9JM) 区域，是 对于产生该信号至关重要。 我们的总体目标是 识别该信号通路的组成部分，以确定 细胞运动的哪些方面被信号抑制，以及 定义该信号在表皮发育过程中的重要性 和伤口愈合。 要定义 JM 域的边界， 我们将分析JM缺失对细胞运动的影响 JM 区域的突变体和显性失活形式。 与 JM 域交互的组件将被标识为 比较免疫共沉淀的蛋白质模式 根据亲和力，包含或缺乏该区域的 E-钙粘蛋白形式 使用 JM 结构域融合蛋白进行纯化，并使用 酵母二杂交系统。 我们将测试这些 JM- 相关成分参与信号传导途径 表达显性失活多肽，从而阻断其 绑定到 JM 域。 我们将测试是否同亲E- 钙粘蛋白结合激活 MAP 激酶。 定义蜂窝 可能受此信号调节的反应，我们将确定 E-钙粘蛋白是否影响膜皱褶和丝状伪足 扩大。 最后，确定本规定的作用 皮肤发育和伤口愈合过程中的活力，我们将 创建并分析转基因小鼠，其中显性失活 E-钙粘蛋白的形式在基础中特异表达 卡拉形成细胞。总之，这些研究将带来更好的结果 了解细胞与细胞接触的机制 调节上皮细胞运动。 这样的知识将证明 有助于促进伤口愈合和控制癌细胞 入侵。