ACTION OF HORMONES ON ADENYLYL CYCLASE SYSTEMS

激素对腺苷酸环化酶系统的作用

• 批准号: 2137303
• 负责人: Lutz Birnbaumer
• 金额: $ 37.04万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-12 至 1998-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2137303
• 关键词: G protein; Rodentias; SDS polyacrylamide gel electrophoresis; adenylate cyclase; bone marrow transplantation; cell cell interaction; disease /disorder model; embryonic stem cell; gastrointestinal disorder; gene expression; gene mutation; genetic strain; hormone regulation /control mechanism; inflammation; laboratory rabbit; polymerase chain reaction; site directed mutagenesis; transfection; western blottings

Heterotrimeric G proteins (subunit composition alpha.Beta/gamma) mediate the effects of a large family of receptors by virtue of their activating or deactivating effects on effector systems. The last years have seen the elucidation of the primary functions of 14 out of the 16 G protein alpha subunits that are now known, as well as for Beta/gamma dimers that form as a result of G proteins activation by GTP under the receptor influence. Recent studies have shown involvement of trimeric G proteins not only in regulation of adenylyl cyclases (AC's), phospholipases (PL's), phosphodiesterases and ion channels, but also in processes such as vesicle budding from endoplasmic reticulum and Golgi networks, and in endosome acidification. Broader roles that mere signal transduction are indicated for G proteins. Mutations of the Galpha subunits that cause constitutive activation have been found in neoplasms and tumors and it has been hypothesized that some alpha subunits may be proto-oncogenes. The molecular cloning and ensuing elucidation of the predicted primary structure of AC led to the discovery of a large degree of molecular and functional diversity (8 genes with products sub-classifiable on the basis of response to Ca2+, calmodulin, Beta/gamma, and possibly activated Gi/alpha's). Up to 5 AC subtypes may be expressed in a single cell as seen with a pituitary tumor cell widely used to study regulation of adenylyl cyclase, phospholipase, ion channel and hormone secretion. During this last term we established in out laboratory the technology required to inactivate or mutate genes in embryonic stem cells and generate via injection into blastocysts animals with an altered genome. Applying this technique to knock out the alpha subunit of Gi2 we gained new information not only about its suspected role in mediating hormonal inhibition of adenylyl cyclase, but also discovered that mice deficient in alphai2 have abnormal T cell-development and function and develop an inflammatory bowel disease resembling ulcerative colitis. Whether these phenomena are causally related is not known. Research proposed in this application focusses wholly on generating novel mouse strains in which genes for alpha/0, alpha/i1, alpha i3 are inactivated and in which alpha/s and alpha/13 and alpha /i2 are mutationally activated. Through breeding, we will combine one or more of these mutations. Other modifications or inactivation of G protein subunits (e.g. alpha/o1 vs. alpha/o2) will be considered and performed depending on outcome and the speed of progress. It is hoped that these studies will 1. test for role(s) of G proteins in developmental processes as well as in cellular functions not yet thought of as targets of G protein regulation; 2. critically test the proto-oncogene potential of Galpha's in the background of a normal mouse; and 3. test for possible functions of alpha subunits for which no function is thus far known.

异三聚体G蛋白（亚基组成alpha.beta/gamma）介导 大型受体家族的影响 或对效应系统停用影响。 最后几年见过 16 g蛋白中14个主要功能的阐明 现在已知的α亚基以及beta/伽玛二聚体 GTP在受体下激活G蛋白的形式 影响。 最近的研究表明三聚体G蛋白的参与 不仅在调节腺苷酸环化酶（AC）中，磷脂酶 （PL），磷酸二酯酶和离子通道，但在此类过程中也 作为囊泡从内质网和高尔基网络中发芽，以及 内体酸化。 仅信号转导的更广泛的作用是 指示G蛋白。 引起的Galpha亚基的突变 在肿瘤和肿瘤中发现了构型激活 已经假设某些α亚基可能是原始基因。 分子克隆和随之而来的预测主要阐明 AC的结构导致发现了一定程度的分子和 功能多样性（基于产物可亚分类的8个基因 对Ca2+，钙调蛋白，β/伽玛的反应 gi/alpha's）。 最多可以在单个单元格中表达高达5个AC亚型 看到垂体肿瘤细胞广泛用于研究调节 腺苷酸环化酶，磷脂酶，离子通道和激素分泌。 在最后一期 需要在胚胎干细胞和 通过注射改变基因组，通过注射到胚泡动物中。 应用此技术来淘汰GI2的α亚基，我们获得了 不仅有关其疑似在介导激素中的作用的新信息 抑制腺苷酸环化酶，但也发现小鼠不足 在Alphai2中，T细胞开发异常和功能并发展 炎症性肠病类似于溃疡性结肠炎。 是否这些 现象是因果关系的。 此应用中提出的研究完全集中于生成新颖的 α/0，alpha/i1，alpha i3的基因的小鼠菌株是 灭活的α/s和alpha/13和alpha/i2是 突变激活。 通过育种，我们将结合一个或多个 这些突变。 G蛋白的其他修饰或失活 将考虑并执行亚基（例如alpha/o1 vs. alpha/o2） 取决于结果和进步速度。 希望这些研究能够1。测试G蛋白的作用 在发育过程以及尚未在细胞函数中 被认为是G蛋白调节的靶标； 2。批判性测试 Galpha在正常小鼠的背景下的原始癌基因； 3。测试α亚基的可能功能 迄今为止，功能是已知的。