MOLECULAR CHARACTERIZATION OF H2 RECEPTOR DUAL SIGNALING

描述(改编自申请人的摘要)：这是一项建议 胃壁组胺H2受体信号转导机制的继续研究 细胞。首席调查员(PI)及其同事 克隆的H2受体的分子结构和功能的表征 并测定其激活腺苷环化酶和磷脂酶C(PLC) 以依赖GTP、对霍乱毒素敏感的方式。其中的机制 受体与两个效应器系统的偶联还有待确定。 此外，PI最近发现受体介导细胞 早期反应基因的增殖和转录激活， C-fos。在目前的提案中，将审查以下内容。(1) 嵌合受体构建和定点突变将用于 阐明与激活有关的受体的结构成分 腺苷环化酶和磷脂酶C；(2)与H2有关的G蛋白 原代细胞和转化细胞中的受体信号将被表征 使用选择性抗体、免疫印迹、GTP标记和分子 技术；以及(3)双重信号的生物学意义将是 探索过了。针对H2受体/G蛋白的寡肽、抗血清和 反义探针将被用来确定 细胞增殖和壁细胞分泌的两条信号通路 活动。

DESCRIPTION (Adapted from applicant's abstract): This is a proposal to continue studies on signaling via histamine H2 receptors in gastric parietal cells. The Principal Investigator (PI) and his colleagues have characterized the molecular structure and function of the cloned H2 receptor and determined that it activates adenylate cyclase and phospholipase C (PLC) in a GTP-dependent, cholera toxin-sensitive manner. The mechanisms whereby the receptor couples to two effector systems remain to be determined. Furthermore, the PI has recently found that the receptor mediates cell proliferation and transcriptional activation of the early response gene, c-fos. In the current proposal the following will be examined. (1) Chimeric receptor constructs and site directed mutagenesis will be used to elucidate the structural components of the receptor linked to activation of adenylate cyclase and phospholipase C; (2) the G proteins involved in H2 receptor signaling in primary and transformed cells will be characterized using selective antibodies, immunoblotting, GTP-labeling and molecular techniques; and (3) the biological significance of dual signaling will be explored. H2 receptor/G protein targeted oligopeptides, antisera and antisense probes will be used to determine the relative importance of the two signaling pathways in cell proliferation and parietal cell secretory activity.