ACTION OF HORMONES ON ADENYLYL CYCLASE SYSTEMS

异源三聚体G蛋白（亚基组成α、β/γ）介导 一个大家族的受体通过其激活 或使效应器系统失效。 在过去的几年里 阐明了16个G蛋白中14个的主要功能 现在已知的α亚基，以及β/γ二聚体， 由于G蛋白被受体下的GTP激活而形成 影响力的社会 最近的研究表明，三聚体G蛋白参与 不仅在腺苷酸环化酶（AC）、磷脂酶 (PL的），磷酸二酯酶和离子通道，但也在过程中， 从内质网和高尔基体网络出芽的小泡， 核内体酸化 更广泛的作用，仅仅是信号转导， 表示为G蛋白。 导致Galpha亚基突变的基因 组成性激活已经在赘生物和肿瘤中发现， 已经假设某些α亚单位可能是原癌基因。 分子克隆和随后的阐明预测的主要 AC的结构导致发现了大量的分子和 功能多样性（8个基因，其产物可根据 对Ca 2+、钙调蛋白、β/γ的反应，并可能激活 Gi/alpha）。 多达5种AC亚型可以在单个细胞中表达， 垂体瘤细胞被广泛用于研究 腺苷酸环化酶、磷脂酶、离子通道和激素分泌。 在上学期，我们在实验室里建立了 胚胎干细胞中的基因突变或突变所必需的， 通过注射到囊胚中产生基因组改变的动物。 应用该技术敲除Gi 2的α亚基，我们获得了 新的信息不仅是关于它在介导激素 腺苷酸环化酶的抑制，而且还发现小鼠缺乏 在α 12中具有异常T细胞发育和功能， 类似溃疡性结肠炎的炎症性肠病。 是否这些 这些现象之间的因果关系尚不清楚。 本申请中提出的研究完全集中在生成新的 其中α/0、α/i1、α i3基因被 失活，其中α/s和α/13和α/12被 突变激活 通过育种，我们将联合收割机一种或多种 这些突变。 G蛋白的其他修饰或失活 将考虑并执行子单元（例如，α/o 1与α/o2） 取决于结果和进展的速度。 希望这些研究能为1。 G蛋白作用试验 在发育过程和细胞功能中， 被认为是G蛋白调节的靶点; 2. 严格检验 正常小鼠背景中的Ga的原癌基因潜能; 和3. 测试α亚单位的可能功能， 功能是已知的。

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.