SIGNAL TRANSDUCTION BY PROTEIN PHOSPHORYLATION

通过蛋白质磷酸化进行信号转导

• 批准号: 3224547
• 负责人: EDMOND H FISCHER
• 金额: $ 24.57万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-09-01 至 1991-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3224547
• 关键词: affinity chromatography; biological signal transduction; carbohydrate metabolism; chemical structure function; enzyme induction /repression; enzyme mechanism; enzyme structure; hormone regulation /control mechanism; human tissue; immunochemistry; insulin; laboratory rabbit; manganese; microtubule associated protein; molecular cloning; phosphatase inhibitor; phosphorylase phosphatase; phosphorylation; placenta; protein sequence; protein tyrosine kinase; tissue /cell culture

We propose to continue our studies on the structure and function of two types of protein-phosphatases involved in the regulation of cellular processes in relation to hormone action or other types of intracellular signalling. Specifically, we are interested in: 1) The mechanism of regulation of phosphorylase phosphatase by Mn2+ ions and phosphorylation of its regulatory subunit (inhibitor-2) known to bring about changes in conformation in the catalytic subunit. 2) The possible involvement of this enzyme in the control of carbohydrate metabolisms in 3T3 cells in response to hormones or growth factors. While insulin and EGF trigger changes in the activity of enzymes directly involved in the synthesis or breakdown of glycogen, the chain of events by which this is brought about is not known. The possibility that the hormones cause the activation of specific protein kinases that act on different phosphorylation sites that may interact with one another will be further investigated. 3) Our main effort will be directed toward the structure and regulation of particulate and cytosolic protein tyrosine phosphatases that have been purified to homogeneity from human placenta. While both enzyme species appear structurally identical, something must account for their different localization. Aside from determining their usual structural and enzymatic properties, sequence information will be obtained for oligonucleotide probes (for cloning), and synthesis of peptides for antibody production (for subcellular and tissue distribution). As of now, essentially nothing is known about the regulation of these enzymes. The possibility that it might be exercised by modifying their subcellular localization, or through specific activators and/or inhibitors will be investigated. Attempts will be made to overexpress the phosphatases in appropriate cell types in order to study their responsiveness to growth factors and oncogenes, and determine what effect this might have on cell functions.

我们建议继续研究其结构和功能 参与调节的两种类型的蛋白磷酸酶 与激素作用或其他类型的细胞过程有关 细胞内信号传导。 具体来说，我们感兴趣的是： 1）Mn2+调节磷酸化酶磷酸酶的机制 离子及其调节亚基的磷酸化（inhibitor-2） 已知会引起催化构象的变化 亚基。 2）该酶可能参与控制 3T3 细胞中碳水化合物代谢响应激素或 生长因子。 虽然胰岛素和 EGF 会引发 直接参与合成或分解的酶的活性 糖原的发生，引起这一事件的链是 不知道。 激素引起激活的可能性 作用于不同磷酸化的特定蛋白激酶 可能相互交互的网站将进一步 调查了。 3）我们的主要努力将集中在结构和 颗粒和胞浆蛋白酪氨酸的调节 已从人类中纯化至同质的磷酸酶 胎盘。 虽然两种酶在结构上看起来相同， 某些东西必须解释它们不同的本地化。 放在一边 通过确定它们通常的结构和酶学特性， 将获得寡核苷酸探针的序列信息 （用于克隆）以及用于抗体生产的肽的合成 （用于亚细胞和组织分布）。 截至目前，基本上 关于这些酶的调节尚不清楚。 这 可以通过修改它们来行使它的可能性 亚细胞定位，或通过特定的激活剂和/或 抑制剂将被研究。 将努力 在适当的细胞类型中过度表达磷酸酶，以便 研究他们对生长因子和癌基因的反应，以及 确定这可能对细胞功能产生什么影响。