MOLECULAR CHARACTERIZATION OF H2 RECEPTOR DUAL SIGNALING

描述(改编自调查员的摘要和/或目标)：这是 重新提交一份研究分子机制和 组胺H2受体偶联cAMP的生物学意义 和钙信号通路。H2受体与cAMP的偶联 通路已经建立；然而，组胺H2受体与 细胞内钙的升高是最近的，曾是第一次 1986年在兔的壁细胞中观察到。这一观察结果现在已经 在包括狗和类似数据在内的几个物种中得到证实 发表在HL60细胞上。在壁细胞中，许多研究已经 证实了cAMP途径和增加的 HCl分泌；然而，组胺的生理相关性 壁细胞中钙信号通路的偶联还没有 已经成立了。 在1991年最近克隆了H2受体之后，申请人 在与山田博士和同事的合作中，他们证明了 将H2受体导入HEPA细胞产生H2受体 腺苷环化酶/cAMP和磷脂酶C/钙/肌醇的偶联 三磷酸(IP3)信号通路。这样做的具体目的是 建议继续这方面的调查如下：1) 描述H2受体的结构成分，它们是 使用嵌合的H2受体与两条通路相连接 基于受体的合成肽；2)G蛋白的特性 参与初级和转化型双重信号通路 单元格；3)基于从前两个特定单元获得的知识 目的：利用H2受体/G蛋白靶向的寡肽、抗血清 和反义探针来确定两者的相对重要性 壁细胞分泌活动中的信号机制。自H2以来 受体的激活也调节了许多生物多样性的 对不同细胞类型的反应，对其功能的理解是 预计将具有广泛的生物学意义。

DESCRIPTION (adapted from investigator's abstract and/or aims): This is a resubmission of an application to study the molecular mechanisms and biological significance of histamine H2 receptor coupling to both cAMP and calcium signaling pathways. Coupling of the H2 receptor to the cAMP pathway is well established; however, histamine H2-receptor associated elevation of intracellular calcium is more recent, having been first observed in rabbit parietal cells in 1986. This observation has now been confirmed in several species including dog and similar data published for HL60 cells.In the parietal cell, numerous studies have demonstrated a clear association between the cAMP pathway and increased HCl secretion; however, the physiological relevance of histamine coupling to the calcium signaling pathway in parietal cells has not been established. Following the recent cloning of the H2 receptor in 1991, the applicant in collaboration with Dr. Yamada and colleagues demonstrated that stable transfection of the H2 receptor into HEPA cells resulted in H2 receptor coupling to adenyl cyclase/cAMP and phospholipase C/calcium/inositol triphosphate (IP3) signaling pathways. The specific aims of this proposal are to continue this line of investigation as follows: 1) To characterize the structural components of the H2 receptor that are linked to the two pathways using chimeric H2 receptors in concert with receptor based synthetic peptides; 2) To characterize the G-proteins involved in dual signaling pathways in both primary and transformed cells; 3) On the basis of knowledge gained from the first two specific aims, to utilize H2 receptor/G-protein-targeted oligopeptides, antisera and antisense probes to determine the relative importance of the dual signaling mechanism in parietal cell secretory activity. Since H2 receptor activation also modulates a number of biologically diverse responses in different cell types, an understanding of its function is expected to have broad biological significance.