NEUROENDOCRINE CGRP RECEPTORS

神经内分泌 CGRP 受体

基本信息

批准号：
2752279
负责人：
IAN M DICKERSON
金额：
$ 19.37万
依托单位：
UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-01-01 至 2002-11-30
项目状态：
已结题

项目摘要

We have recently discovered a novel low molecular weight protein which appears to be required for signal transduction at receptors for calcitonin gene-related peptide (CGRP), and potentially at other G protein-coupled receptors. This small hydrophilic protein which has been named the Receptor Component Protein (RCP) is required for CGRP- mediated signal transduction in NIH3T3 cells. We have demonstrated the requirement for RCP in CGRP receptor function by making stable NIH3T3 cell lines which express RCP antisense cDNA, and have observed a loss of RCP protein with a concomitant loss of CGRP receptor activity. RCP was discovered in the context of the CGRP receptor, but its effects may not be limited to receptors for CGRP. In an effort to learn more about the function of this novel protein we have focused our initial studies on CGRP receptor activation. We do not believe that RCP represents a receptor itself, as transfection of RCP into COS fibroblast cells does not yield functional CGRP receptors. We instead hypothesize that RCP works in conjunction with a membrane-spanning, ligand-binding protein to form a functional CGRP receptor. Two CGRP receptors have recently been identified, but cotransfection of RCP with either of these receptors into COS fibroblasts fails to reconstitute CGRP receptor function, implicating a novel receptor working in conjunction with RCP in NIH3T3 cells. Our hypothesis is that RCP effects either targeting of receptor to the cell surface, or coupling of the receptor to signal transduction molecules. The results from the experiments outlined in this proposal will discern between these two possibilities. The Specific Aims of this proposal are to: 1) Determine if the loss of RCP in NIH3T3 cells inhibits receptors other than CGRP. 2) Determine if RCP functions in receptor sorting or receptor coupling. 3) Identify the receptor(s) in NIH3T3 cells that require RCP for function. We are using the CGRP receptor present in NIH3T3 cells as a model for RCP-dependent receptors to determine the mechanism of RCP function. CGRP is one of the most potent vasodilators known, and CGRP binding sites are distributed widely throughout the cardiovascular system. Characterization of the proteins involved in CGRP receptor activation is important for developing CGRP receptor model systems, which will facilitate development of therapeutic ligands for treatment of cardiovascular disease such as hypertension.

我们最近发现了一种新型低分子量蛋白质，似乎是受体信号转导所必需的降钙素基因相关肽 (CGRP)，以及其他可能的 G 蛋白质偶联受体。这种小的亲水性蛋白质具有被命名为受体成分蛋白 (RCP) 是 CGRP 所必需的- NIH3T3 细胞中介导的信号转导。我们已经证明了通过稳定 NIH3T3 来实现 CGRP 受体功能中 RCP 的要求表达 RCP 反义 cDNA 并观察到缺失的细胞系 RCP 蛋白的减少伴随着 CGRP 受体活性的丧失。 RCP 是在 CGRP 受体的背景下发现的，但其作用可能不限于CGRP受体。为了努力了解更多我们初步研究的重点是这种新型蛋白质的功能 CGRP 受体激活。我们不认为 RCP 代表受体本身，因为 RCP 转染到 COS 成纤维细胞中不产生功能性 CGRP 受体。相反，我们假设 RCP 与跨膜配体结合蛋白结合使用形成功能性 CGRP 受体。最近发现了两种 CGRP 受体已被鉴定，但 RCP 与其中任何一个共转染受体进入 COS 成纤维细胞无法重建 CGRP 受体功能，暗示一种与 RCP 协同作用的新型受体在 NIH3T3 细胞中。我们的假设是 RCP 影响受体的靶向细胞表面，或受体与信号转导的偶联分子。本提案中概述的实验结果将辨别这两种可能性。本次活动的具体目标建议是： 1) 确定 NIH3T3 细胞中 RCP 是否丢失抑制 CGRP 以外的受体。 2) 确定 RCP 是否起作用受体分选或受体偶联。 3) 识别受体需要 RCP 发挥功能的 NIH3T3 细胞。我们正在使用 CGRP NIH3T3 细胞中存在的受体作为 RCP 依赖性受体的模型确定RCP功能的机制。 CGRP 是最重要的之一已知有效的血管扩张剂，且 CGRP 结合位点分布广泛整个心血管系统。蛋白质的表征参与 CGRP 受体激活对于 CGRP 的形成很重要受体模型系统，这将促进治疗药物的开发用于治疗高血压等心血管疾病的配体。