Regulation of endothelial adhesion by VE-cadherin endocytosis

VE-钙粘蛋白内吞作用对内皮粘附的调节

• 批准号: 8692584
• 负责人: Benjamin Andrew Nanes
• 金额: $ 3.14万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8692584
• 关键词: Adaptor Protein Complex 2; Adaptor Signaling Protein; Adherens Junction; Adhesions; Amino Acid Sequence; Anti-Inflammatory Agents; Anti-inflammatory; Binding; Binding Sites; Blood Vessels; Cadherins; Cell Adhesion; Cell Adhesion Molecules; Cell membrane; Cell-Cell Adhesion; Cells; Clathrin; Cytoplasmic Tail; Development; Disease; Dissociation; Down-Regulation; Dynamin; Edema; Endocytosis; Endothelial Cells; Family; Family Dasypodidae; Functional disorder; Goals; Hemorrhage; Human Herpesvirus 8; Infection; Inflammation; Inflammatory; Intercellular Junctions; Knowledge; Measures; Mediating; Membrane Protein Traffic; Membrane Proteins; Modeling; Mutation; Myocardial Infarction; Pathology; Pathway interactions; Permeability; Protein Binding; Regulation; Role; Site; Stroke; Surface; Testing; Tissues; Tube; Ubiquitination; Vascular Permeabilities; Work; Wound Healing; angiogenesis; cadherin 5; cell motility; drug development; human disease; insight; monolayer; mouse model; prevent; ubiquitin ligase; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): Vascular development and wound healing both depend on dynamic control of endothelial cell adhesion. However, inappropriate loss of adhesion contributes to pathology in inflammatory conditions. Modulation of cell-cell junctions controls endothelial adhesion, and understanding the mechanisms of junction regulation will lend insight into normal vascular development and disease. In this application, we seek to investigate the role of endocytosis in the regulation of vascular endothelial cadherin (VE-cadherin), the main adhesion molecule in endothelial adherens junctions. Despite the importance of VE-cadherin to vessel development, angiogenesis, and inflammation, relatively little is known about the mechanisms of its regulation. One way cells regulate the abundance of plasma membrane proteins such as VE-cadherin is through membrane trafficking. Previous work by our lab demonstrates that p120-catenin (p120), an Armadillo family protein that binds to the VE- cadherin cytoplasmic tail, protects VE-cadherin from rapid internalization and degradation. We hypothesize that disrupting p120 binding to VE-cadherin unmasks an endocytic adaptor binding site, leading to internalization of VE-cadherin and loss of adhesion in endothelial cells. To test this hypothesis, we will pursue the following specific aims. First, we wll identify the amino acid sequences in the VE-cadherin cytoplasmic tail which mediate adaptor binding and endocytosis. We will also test the functional consequences of mutations in VE-cadherin which prevent endocytosis. Second, we will use the ubiquitin ligase K5, which causes rapid down-regulation of VE-cadherin, as a model to determine if disrupting p120 binding is used as a mechanism to control VE-cadherin levels. We will identify the currently unknown mechanism by which K5 causes VE- cadherin down-regulation and its relationship to endogenous pathways for VE-cadherin control. Our long-term goal is to reveal how endothelial cells modulate the strength of cell-cell adhesion, leading to a better understanding of angiogenesis and new treatments for inflammatory disease.

描述(申请人提供)：血管发育和伤口愈合都依赖于内皮细胞黏附的动态控制。然而，在炎症条件下，不适当的粘连丧失会导致病理改变。细胞-细胞连接的调节控制内皮细胞的黏附，了解连接调节的机制将有助于深入了解正常的血管发育和疾病。在这一应用中，我们试图研究内吞作用在调节血管内皮细胞钙粘附素(VE-cadherin)中的作用，VE-钙粘附素是内皮细胞黏附连接中的主要黏附分子。尽管VE-钙粘附素在血管发育、血管生成和炎症中具有重要作用，但人们对其调控机制知之甚少。细胞调节VE-钙粘附素等质膜蛋白丰度的一种方式是通过膜运输。我们实验室以前的工作表明，p120-catenin(P120)是一种Armadillo家族蛋白，它与VE-钙粘蛋白胞浆尾部结合，保护VE-钙粘蛋白不被快速内化和降解。我们假设，破坏p120与VE-钙粘蛋白的结合会暴露出一个内吞适配器结合部位，导致VE-钙粘蛋白内化并失去内皮细胞的黏附。为了验证这一假设，我们将追求以下具体目标。首先，我们将确定VE-钙粘蛋白胞浆尾部的氨基酸序列，它介导了接头结合和内吞作用。我们还将测试VE-钙粘附素突变防止内吞作用的功能后果。其次，我们将使用泛素连接酶K5，它导致VE-钙粘蛋白的快速下调，作为一个模型来确定是否使用破坏p120结合作为控制VE-钙粘蛋白水平的机制。我们将确定目前尚不清楚的K5导致VE-钙粘蛋白下调的机制，以及它与VE-钙粘蛋白调控的内源性途径的关系。我们的长期目标是揭示内皮细胞如何调节细胞间黏附的强度，从而更好地理解血管生成和炎症性疾病的新治疗方法。