ACTION OF HORMONES ON ADENYLYL CYCLASE SYSTEMS

异源三聚体G蛋白(亚基组成α，β/伽马)起中介作用 受体大家族的激活作用 或使效应器系统失效的效果。在过去的几年里， 16G蛋白中14个主要功能的阐明 现在已知的阿尔法亚基，以及贝塔/伽马二聚体 受体下G蛋白被GTP激活而形成 影响力。最近的研究表明，三聚体G蛋白参与其中 不仅在腺酰环化酶(AC‘s)、磷脂酶 (PL‘s)、磷酸二酯酶和离子通道，但也在这些过程中 作为来自内质网和高尔基体网络的囊泡萌发，以及在 内体酸化。仅仅是信号转导的更广泛的作用 表明是G蛋白。引起GALPHA亚基的突变 在肿瘤和肿瘤中发现了结构性激活，而且它 已经假设一些阿尔法亚基可能是原癌基因。 预测的原发基因的分子克隆和随后的阐明 AC的结构导致了很大程度上的分子和 功能多样性(8个基因，其产物可在此基础上细分 对钙、钙调蛋白、β/伽马的反应，并可能被激活 GI/阿尔法)。在单个细胞中最多可以表达5个AC亚型为 被广泛用于研究脑脊液分泌调节的脑垂体瘤细胞 腺苷环化酶、磷脂酶、离子通道和激素分泌。 在这最后一个学期里，我们在实验室里建立了这项技术。 使胚胎干细胞中的基因失活或突变所必需的 通过注射到基因组改变的囊胚动物体内产生。 应用这一技术敲除GI2的α亚基，我们获得了 新的信息不仅是关于它在调节荷尔蒙中的可疑作用 抑制腺苷环化酶，还发现小鼠存在缺陷 在Alphai2中有T细胞发育和功能异常，并发展为 类似溃疡性结肠炎的炎症性肠病。不管是这些 现象之间有因果关系是未知的。 本申请中提出的研究完全集中在生成小说上 α/0、α/i1、αi3基因分别为 停用，其中α/S、α/13和α/i2是 突变激活。通过繁殖，我们将结合一个或多个 在这些突变中。G蛋白的其他修饰或失活 将考虑并执行亚单位(例如，α/o1与α/O2) 取决于结果和进展的速度。 希望这些研究将1.检验G蛋白的作用(S) 在发育过程中以及在细胞功能上还没有 被认为是G蛋白调控的靶点；2.严格测试 正常小鼠背景下Galpha‘s原癌基因潜能的研究 以及3.检测阿尔法亚基的可能功能 到目前为止，函数是已知的。

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.