Regulation of EGF Receptors by G protein receptor

G蛋白受体对EGF受体的调节

• 批准号: 6368869
• 负责人: John R Raymond
• 金额: $ 21.83万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6368869
• 关键词: G protein; G protein coupled receptor kinase; acidity /alkalinity; biological signal transduction; cell component structure /function; epidermal growth factor; green fluorescent proteins; growth factor receptors; immunoprecipitation; intermolecular interaction; intracellular transport; lysosomes; membrane transport proteins; metalloendopeptidases; microinjections; molecular site; neutralizing antibody; phosphorylation; proteasome; protein kinase C; protein localization; protein structure function; protein tyrosine kinase; receptor expression; receptor mediated endocytosis; tissue /cell culture

DESCRIPTION (provided by applicant): The purpose of this application is to explore the cross talk that occurs between G protein-coupled receptors (GPCR's) and receptor tyrosine kinases (RTK's), especially the epidermal growth factor receptor (EGFR). We, like others, have made the observation that activation of GPCR's leads to transphosphorylation and activation of EGFR's. We have also made the novel finding that prior activation of GPCR's leads to a profound desensitization of the EGFR's. The purpose of this application is to gain mechanistic insights into the desensitization process. In Specific Aim 1, we will determine which signaling pathway(s) is/are required for desensitization and transphosphorylation of the EGF receptor by GPCR's. We will mainly use primary cultures of cell types that have endogenous GPCR's and EGFR's. Those studies will be augmented by judicious use of transfected cells. Major questions to be answered in this aim are: What signaling molecules link GPCR activation to EGFR phosphorylation and transactivation? Are they the same as those that induce EGFR desensitization? We will focus primarily on the roles of protein kinase C, the non-receptor tyrosine kinase Src, and sodium proton exchanger type I (NHE-I). Is endocytosis of EGFR required for GPCR-mediated desensitization of EGFR? Is heparin-bound EGF (HB-EGF) required for either desensitization or transactivation of the EGFR? In order to answer this question, we will use a number of complementary methods to neutralize the native HB-EGF in primary cells in culture. In Specific Aim 2, we will determine the intracellular fate of the EGFR's after stimulation of GPCR's. To what compartments are the EGFR targeted after transactivation by GPCR' s? What other signaling components are internalized with the EGFR (GPCR, NRTK, NHE-1, HB-EGF), and are they processed through the same pathways? What enzymatic pathways are required for down-regulation of the EGFR? We will study the roles of lysosomes, proteasome, and zinc-regulated metalloproteinases in this process. These studies address important gaps in our knowledge of GPCR signals that regulate the functions of RTK's.

描述（申请人提供）：本申请的目的是 探索G蛋白偶联受体（GPCR）之间发生的串扰 和受体酪氨酸激酶（RTK），尤其是表皮生长因子 受体（EGFR）。我们和其他人一样，已经观察到 GPCR导致EGFR的磷酸化和激活。我们也有 小说发现GPCR的先前激活导致了深刻的 EGFR的脱敏。此应用程序的目的是获取 对脱敏过程的机械洞察力。 在特定的目标1中，我们将确定需要/需要哪种信号通路 GPCR的EGF受体脱敏和磷酸化。我们 将主要使用具有内源性GPCR的细胞类型的原发性培养物和 EGFR的。这些研究将通过明智地使用转染的细胞来增强。 在此目的中要回答的主要问题是：哪些信号分子链接 GPCR激活EGFR磷酸化和反式激活？他们是一样的吗 像诱导eGFR脱敏的人一样？我们将主要关注角色 蛋白激酶C，非受体酪氨酸激酶SRC和质子钠 交换器I型（NHE-I）。 GPCR介导的EGFR的内吞作用是 EGFR脱敏？两者都需要肝素结合的EGF（HB-EGF） EGFR的脱敏或反式激活？为了回答这个问题 问题，我们将使用多种补充方法中和 培养中原代细胞中的天然HB-EGF。 在特定目标2中，我们将确定EGFR的细胞内命运 刺激GPCR。在egfr的目标 GPCR的反式激活？其他哪些信号组件是内部化的 使用EGFR（GPCR，NRTK，NHE-1，HB-EGF），它们是否通过 同样的途径？下调需要什么酶促途径 egfr？我们将研究溶酶体，蛋白酶体和锌调节的作用 金属蛋白酶在此过程中。这些研究解决了我们的重要差距 对调节RTK功能的GPCR信号的了解。