HB-EGF AND ITS RECEPTORS

HB-EGF 及其受体

• 批准号: 6519487
• 负责人: MICHAEL KLAGSBRUN
• 金额: $ 28.31万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6519487
• 关键词: SDS polyacrylamide gel electrophoresis; binding proteins; biological signal transduction; cell adhesion; confocal scanning microscopy; epidermal growth factor; gene expression; gene targeting; genetic transcription; genetically modified animals; growth factor receptors; heparin; immunocytochemistry; immunoprecipitation; in situ hybridization; laboratory mouse; mitogens; myogenesis; northern blottings; posttranslational modifications; protein structure function; smooth muscle; tissue /cell culture; vascular endothelial growth factors; western blottings; wound healing

HB-EGF is synthesized as a membrane-anchored juxtacrine growth factor that is shred to released mature HB-EGF, a potent mitogen and chemotactic factor for smooth muscle cells (SMC). HB-EGF activity is mediated by two receptors, ErbB1 and ErbB4. For the most part HB-EGF function in vivo is not well characterized. In the first aim the role of SMC-derived HB-EGF in mediating SMC-EC interactions in blood vessels will be examined in vivo and in vitro. In addition, potential differences in the roles of transmembrane and mature HB-EGF will be analyzed in vivo in transgenic mice. The second aim involves characterization of novel HB-EGF receptors. One is a 140 kDa protein that has been recently purified and cloned, binds HB-EGF specifically and as a soluble receptor is a specific HB-EGF antagonist. In addition, two novel ErbB4 isoforms, one with an alteration in the juxtamembrane domain that can not be shed and one that lacks the PI3-kinase binding site and can not activate PI3-kinase activity will be further characterized. These proposed studies on HB-EGF function and receptors are significant since HB-EGF has been suggested to contribute to normal physiological responses such as wound healing and pathological processes such as atherosclerosis and pulmonary hypertension. The Specific Aims of the proposal are: 1. To Investigate the Role of HB-EGF in Blood Vessels including: a) analysis of temporal and spatial HB-EGF promoter-lacZ reporter gene expression in blood vessels of transgenic mice; b) analysis of the effects of HB-EGF on EC-SMC interactions in vitro; c) over- expression of mature, transmembrane and non-cleavable transmembrane forms in the blood vessels of transgenic mice; d) generation of transgenic mice expressing mature HB-EGF only, by deleting the transmembrane and cytoplasmic domains. 2. To Characterize Novel HB-EGF Receptors including: a) Structure and functional analysis of a novel specific 140 kDa HB-EGF receptor; b) characterization of novel alternatively spliced ErbB4 isoforms differing in the juxtamembrane domain and the PI-3K binding domains.

HB-EGF 被合成为膜锚定的近分泌生长因子，被撕碎后释放出成熟的 HB-EGF，这是平滑肌细胞 (SMC) 的有效有丝分裂原和趋化因子。 HB-EGF 活性由两种受体 ErbB1 和 ErbB4 介导。大多数情况下，HB-EGF 的体内功能尚未得到很好的表征。第一个目标是在体内和体外检查 SMC 衍生的 HB-EGF 在介导血管中 SMC-EC 相互作用中的作用。此外，还将在转基因小鼠体内分析跨膜和成熟 HB-EGF 作用的潜在差异。第二个目标涉及新型 HB-EGF 受体的表征。一种是最近纯化和克隆的 140 kDa 蛋白质，特异性结合 HB-EGF，并且作为可溶性受体是特异性 HB-EGF 拮抗剂。此外，将进一步表征两种新的 ErbB4 亚型，一种在近膜结构域中具有无法脱落的改变，另一种缺乏 PI3 激酶结合位点且不能激活 PI3 激酶活性。这些关于 HB-EGF 功能和受体的研究具有重要意义，因为 HB-EGF 被认为有助于正常的生理反应，例如伤口愈合和病理过程，例如动脉粥样硬化和肺动脉高压。该提案的具体目标是： 1. 研究HB-EGF在血管中的作用，包括： a) 分析转基因小鼠血管中HB-EGF启动子-lacZ报告基因的时空表达； b) 分析HB-EGF对体外EC-SMC相互作用的影响； c) 转基因小鼠血管中成熟的跨膜和不可切割的跨膜形式的过度表达； d)通过删除跨膜和细胞质结构域，产生仅表达成熟HB-EGF的转基因小鼠。 2. 表征新型 HB-EGF 受体，包括： a) 新型特异性 140 kDa HB-EGF 受体的结构和功能分析； b) 新型选择性剪接 ErbB4 同工型的表征，其近膜结构域和 PI-3K 结合结构域有所不同。