G PROTEIN LINKED REGULATION OF INTEGRINS BY IAP (CD47)

IAP 对整合素的 G 蛋白相关调控 (CD47)

• 批准号: 6388730
• 负责人: JOHN F MCDONALD
• 金额: $ 4.38万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6388730
• 关键词: CD antigens; G protein; Sf9 cell line; angiogenesis; biological signal transduction; cell adhesion; cell growth regulation; cell migration; cholesterol; genetic manipulation; glycoproteins; integrins; ligands; membrane proteins; mutant; protein protein interaction; protein structure function; receptor coupling; receptor expression; thrombospondins; transfection /expression vector; vascular endothelium

Integrins initiate signaling pathways that impact tissue organization, inflammation, blood clotting, oncogenesis and angiogenesis upon binding of extracellular matrix proteins, in the regulation of biological processes. In this proposal, the role of integrin-associated protein (IAP, CD47), a co-receptor in mediating integrin signaling, will be studied by manipulation of both the receptor apparatus and the ligand structure. The C- terminal cell-binding domain (CBD) of thrombospondin (TS) is a ligand of IAP, and peptides derived from the CBD stimulate integrin-dependent processes via heterotrimeric G proteins. To define the mechanism of G protein coupling to the integrin-IAP complex, 1) a model expression system will be established for integrins, IAP and G protein subunits to evaluate receptor function in cellular assays upon treatment with IAP agonists; 2) direct measurements of G protein coupling will be carried out in the transfected cells and correlated with functional assays to identify the role of each component in the signaling complex; and 3) expression and mutagenesis of TS and CBD will be carried out to identify the determinants for IAP activation. By correlating changes in the interactions of the receptor and G protein components with downstream or "read-out" cellular functions, these studies should begin to define the molecular basis for the role of IAP in integrin-regulated biological processes such as angiogenesis, tumorigenesis and wound healing.

整联蛋白会引发信号通路，从而在生物学过程的调节中影响组织组织，炎症，血液凝结，肿瘤发生和血管生成。在此提案中，通过操纵受体设备和配体结构的操纵，将研究与整合素相关蛋白（IAP，CD47）的作用。血小板传播（TS）的C-末端细胞结合结构域（CBD）是IAP的配体，源自CBD的肽通过异核三聚体G蛋白刺激整联蛋白依赖性过程。为了定义G蛋白与整联蛋白-IAP复合物的机制，1）将为整联蛋白，IAP和G蛋白亚基建立模型表达系统，以评估用IAP激动剂治疗后细胞测定中的受体功能； 2）将直接测量G蛋白耦合的直接测量，将在转染的细胞中进行，并与功能测定法相关，以识别每个组件在信号传导复合物中的作用； 3）将执行TS和CBD的表达和诱变，以识别IAP激活的决定因素。通过将受体和G蛋白成分与下游或“读出”细胞功能的相互作用的变化相关联，这些研究应开始定义IAP在整联蛋白调节的生物学过程中的作用的分子基础，例如血管生成，肿瘤发生，肿瘤发生和伤口愈合。