HORMONAL CONTROL OF HEPATIC METABOLISM AND FUNCTION

这个项目的总体目标是阐明 荷尔蒙调节肝功能。项目的具体目标 研究荷尔蒙的作用机制，如 血管紧张素II为血管紧张素转换酶提供刺激和抑制输入 手机。刺激性投入的产生是由于增加了对 磷脂酰肌醇4，5-二磷酸产生细胞内两个 信使、钙离子和二酰甘油(DAG)。这些消息被激活 不同的蛋白激酶，如磷酸化酶和蛋白激酶C 然后调节细胞中的不同功能。抑制性输入 是由与胰升糖素刺激的腺苷直接相互作用产生的 通过腺苷酸镍鸟嘌呤核苷酸调节成分的环化酶 循环酶。提出了四种类型的实验方案。第一个项目 将探索已知的蛋白激酶对钙离子的反应能力 和DAG磷酸化和失活糖原合成酶，这是一种重要的 受多位点磷酸化调控的酶。该网站(S)被磷酸化 通过完整细胞中的每一种酶以及由此对酶的影响 活动将是相互关联的。在第二个项目中，DAG的效果 而钙离子对质膜磷酸化的信号将 探索过了。这些研究将通过分解膜蛋白来进行 来自对照和激素处理的~(32)P标记的肝细胞 立体凝胶并用放射自显影将其可视化。密度 有关自动放射照相的信息将在一个 电脑。在第三个项目中，血管紧张素II和血管紧张素Ⅱ的可能作用 蛋白激酶C在调节肝脏抗紧张素原合成中的作用 将会被探索。这项研究将通过测量 蛋白质的合成及用cdna探针检测 血管紧张素原基因表达水平。在第四个项目中，分子 镍鸟嘌呤核苷酸结合蛋白与肌动蛋白的相互作用 血管紧张素II受体将通过重组纯化的镍来探索 蛋白质进入膜，经GTP-伽马-S处理后还原 受体的亲和力。的高亲和力状态的恢复 随着Ni的重组，受体有望出现。

The overall goal of this project is to elucidate the mechanisms by which hormones regulate hepatic function. The specific goals of the project period are to examine the mechanism of action of hormones such as angiotensin II that provide both stimulatory and inhibitory inputs to the cell. The stimulatory inputs are generated by increased breakdown of phosphatidylinositol 4,5 bisphosphate which produces two intracellular messengers, Ca2+ ion and diacylglycerol (DAG). These messages activate distinct protein kinases such as phosphorylase kinase and Protein Kinase C which then regulate different functions in the cell. The inhibitory inputs are generated by a direct interaction with glucagon stimulated adenylate cyclase through the Ni guanine nucleotide regulatory component of adenylate cyclase. Four types of experimentation are proposed. The first project will explore the ability of protein kinases known to respond to Ca2+ ion and DAG to phosphorylate and inactivate glycogen synthase, an important enzyme regulated by multisite phosphorylation. The site(s) phosphorylated by each kinase in the intact cell and the resultant effect on enzyme activity will be correlated. In the second project, the effects of the DAG and Ca2+ signals on the phosphorylation of plasma membranes will be explored. These studies will be carried out by resolving membrane proteins from control and hormone treated 32P-labelled hepatocytes on two dimensional gels and visualizing them with autoradiography. The density information on the autoradiographs will be integrated with the aid of a computer. In a third project, the possible role of angiotensin II and Protein Kinase C in regulating the hepatic synthesis of antiotensinogen will be explored. This study will be carried out both by measuring the synthesis of the protein and by using a cDNA probe to measure angiotensinogen mRNA levels. In the fourth project, the molecular interactions between the Ni guanine nucleotide binding protein and the angiotensin II receptor will be explored by reconstituting purified Ni protein into membranes that have been treated with GTP-Gamma-S to reduce the affinity of the receptor. Recovery of a high affinity state of the receptor is expected following reconstitution of Ni.