ANALYSIS OF HORMONE REGULATED ADENYLYCYCLASE ISOFORMS

描述（改编自申请人的摘要）： 环腺苷酸（cAMP）水平已被证明会影响许多细胞 蛋白质磷酸化状态变化的基础过程， 离子通道电导和基因表达。的浓度 胞内cAMP主要在其合成水平上受到控制 通过腺苷酸环化酶的激素调节， ATP转化为cAMP。腺苷酸环化酶活性受激素调节 通过异源三聚体G蛋白偶联， 变成α和β-γ二聚体; α和β-γ都能够 调节环化酶。腺苷酸环化酶的九种异构体，分别由 基因，已被确定的日期，并已被证明是受调控的 单个G蛋白亚基以同种型特异性方式。额外 腺苷酸环化酶的特性是它们整合多个腺苷酸环化酶的能力。 同时的荷尔蒙输入。适当的腺苷酸环化酶的重要性 通过识别受体中的突变来强调调节 和G蛋白成分在许多人类疾病状态中发现， 功能亢进性甲状腺腺瘤、假性甲状旁腺功能减退症和McCune-Albright 综合征在第一个目标中，首席研究员建议检查 腺苷酸环化酶基因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物化学方法， 并表征腺苷酸环化酶的激活突变等位基因。第三 他的目标是研究腺苷酸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 cAMP调节。在最后的目标中，首席研究员将检查 腺苷酸环化酶突变可能参与病理生理状态 并检测激活突变腺苷酸环化酶的致癌潜力 等位基因这些拟议的研究应提供一个重要的理解， 腺苷酸环化酶的调节机制，一般来说，G 蛋白偶联效应系统，并将提供阐明的基础 腺苷酸环化酶的结构或功能可能存在缺陷， 人类疾病状态中的异常信号转导。

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.