HORMONAL REGULATION OF CELLULAR METABOLISM

本项目主要研究蛋白激酶和蛋白质的功能 磷酸酶在转导由激素引发的细胞外信号中的作用， 神经递质、生长因子和抗原。 共价修饰 蛋白质的磷酸化/去磷酸化起着核心作用 在介导由配体-受体引起的许多细胞事件中， 各种第二信使的相互作用和产生。 几 蛋白激酶，尤其是Ca 2 +/磷脂/甘油二酯- 受刺激的蛋白激酶C家族和磷酸酶已经被 从大鼠脑中制备，用于鉴定蛋白质底物 被这些酶所修饰。 已经分离出几种新的蛋白质 通过离子交换和反相色谱法及其部分 确定的氨基酸序列。 磷脂的作用和 Ca 2+结合蛋白、钙调蛋白和S-100蛋白在 这些蛋白质的磷酸化/去磷酸化 研究了 此外，蛋白激酶C的修饰 底物，神经颗粒蛋白，通过氧化剂如过氧化氢 而一氧化氮已经被证明会影响激酶催化的 磷酸化 这些新蛋白的cDNA的分子克隆 激酶C底物正在进行中。 的基因组结构 CNS特异性蛋白激酶~同工酶及其底物神经颗粒蛋白， 已被阐明。 控制组织特异性的机制 这两个基因的发育阶段调控表达， 目前正在调查中。

This project focuses on the functions of protein kinases and protein phosphatases in transducing extracellular signals initiated by hormones, neurotransmitters, growth factors, and antigens. Covalent modification of proteins by phosphorylation/dephosphorylation plays a central role in mediating many cellular events resulting from ligand-receptor interaction and generation of a variety of second messengers. Several protein kinases, especially the Ca2+/phospholipid/diacylglycerol- stimulated protein kinase C family, and phosphatases have been prepared from rat brain for the identification of protein substrates modified by these enzymes. Several novel proteins have been isolated by ion-exchange and reverse phase chromatography and their partial amino acid sequences determined. The effects of phospholipids and Ca2+-binding proteins, calmodulin, and S-100 protein on the phosphorylation/dephosphorylation of these proteins are being investigated. In addition, modification of the protein kinase C substrate, neurogranin, by oxidizing agents such as hydrogen peroxide and nitric oxide has been shown to influence the kinase-catalyzed phosphorylation. Molecular cloning of the cDNAs of these novel protein kinase C substrates is in progress. The genomic structures of the CNS-specific protein kinase ~ isozyme and its substrate, neurogranin, have been elucidated. The mechanisms controlling the tissue-specific and developmental stage-regulated expression of these two genes are currently being investigated.