ANALYSIS OF HORMONE REGULATED ADENYLYCYCLASE ISOFORMS

描述(改编自申请人的摘要)：细胞内调制 环磷酸腺苷(CAMP)水平已被证明对许多细胞 蛋白质磷酸化状态的潜在变化过程，调节 离子通道电导和基因表达。浓缩物 细胞内cAMP主要受其合成水平的控制。 通过腺酰环化酶的激素调节，该酶催化 三磷酸腺苷转化为环磷酸腺苷。腺酰环化酶活性受激素调节 它通过异三聚体G蛋白偶联，当被激活时，解离 转化为α和β-伽马二聚体；α和β-伽马都能够 调节循环酶。腺酰环化酶的九种异构体，由单独编码 基因，到目前为止已经被识别出来，并被证明是受 单个G蛋白亚基以同工型特有的方式。一项额外的 腺酰环化酶的性质是它们整合多个 同时的荷尔蒙输入。正确的腺酰环化酶的重要性 受体突变的识别强调了调节作用。 以及在许多人类疾病状态中发现的G蛋白成分，如 甲状腺功能亢进性腺瘤、假性甲状旁腺功能减退症和McCune-Albright 综合症。在第一个目标中，首席调查员建议检查 G对腺酰环化酶类型特异性调控的结构基础 蛋白质β-γ和抑制性Gi-α亚基。在第二个目标中， 首席研究员将使用遗传和生化方法来识别 并鉴定了腺苷环化酶的激活突变等位基因。在第三节 目的，他将研究腺酰环化酶突变体在细胞培养中的行为。 系统，并确定这些突变对细胞内的影响 营地规定。在最终目标中，首席调查员将审查 腺酰环化酶突变可能与病理生理状态有关 并检测激活突变的腺苷环化酶的致癌潜力 等位基因。这些拟议的研究应该提供对以下方面的重要理解 腺酰环化酶的调节机制和一般G 蛋白质偶联效应系统，并将为阐明 腺酰环化酶可能的结构或功能缺陷是 人类疾病状态下的异常信号转导。

DESCRIPTION (adapted from applicant's abstract): Modulation of intracellular cyclic AMP (cAMP) levels has been shown to impact on a number of cellular processes underlying changes in protein phosphorylation state, regulation of ion channel conductance, and gene expression. The concentration of intracellular cAMP is principally controlled at the level of its synthesis through the hormonal regulation of adenylyl cyclase, the enzyme catalyzing the conversion of ATP to cAMP. Adenylyl cyclase activity is regulated by hormones that couple through heterotrimeric G proteins that when activated, dissociate into alpha and beta-gamma dimers; both alpha and beta-gamma are capable of regulating the cyclase. Nine isoforms of adenylyl cyclase, encoded by separate genes, have been identified to date, and have been shown to be regulated by individual G protein subunits in an isoform-specific fashion. An additional property of adenylyl cyclases is their ability to integrate multiple simultaneous hormonal inputs. The importance of proper adenylyl cyclase regulation is underscored by the identification of mutations in the receptor and G protein components found in a number of human disease states such as hyperfunctioning thyroid adenomas, pseudohypoparathyroidism and McCune-Albright syndrome. In the first aim the principal investigator proposes to examine the structural basis for the type-specific regulation of adenylyl cyclases by G protein beta-gamma and inhibitory Gi-alpha subunits. In the second aim, the principal investigator will use genetic and biochemical approaches to identify and characterize activating mutant alleles of adenylyl cyclase. In the third aim, he will examine the behavior of adenylyl cyclase mutants in cell culture systems, and determine the consequences of these mutations on intracellular cAMP regulation. In the final aim, the principal investigator will examine the possible involvement of adenylyl cyclase mutations in pathophysiological states and examine the oncogenic potential of activating mutant adenylyl cyclase alleles. These proposed studies should provide a significant understanding of the mechanisms underlying the regulation of adenylyl cyclases and in general, G protein-coupled effector systems, and will provide the basis for elucidating possible defects in adenylyl cyclase structure or function as the basis for abnormal signal transduction in human disease states.