SUBSTRATES OF P60SRC PROTEIN TYROSINE KINASE

P60SRC 蛋白酪氨酸激酶的底物

• 批准号: 2096828
• 负责人: ALBERT B REYNOLDS
• 金额: $ 10.29万
• 依托单位: ST. JUDE CHILDREN'S RESEARCH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-04-01 至 1997-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2096828
• 关键词: biological signal transduction; cell transformation; chemical binding; enzyme substrate; fluorescence microscopy; genetic library; genetic mapping; in situ hybridization; laboratory mouse; laboratory rabbit; messenger RNA; molecular cloning; monoclonal antibody; northern blottings; nucleic acid probes; nucleic acid sequence; phosphorylation; polymerase chain reaction; posttranslational modifications; protein structure function; protein tyrosine kinase; protooncogene; southern blotting

Activated receptor and nonreceptor protein tyrosine kinases (PTKs) are presumed to mediate their diverse effects in signal transduction and cell transformation by phosphorylating cellular proteins on tyrosine and thereby modifying their biochemical activities. Because many cellular substrates of PTKs have not been molecularly characterized and their functions remain unknown, our understanding of the biochemical pathways that relay PTK- induced signals remains incomplete. The central theme of this proposal is to characterize novel PTK substrates and to determine their putative role(s) in signal transduction and cell transformation. Using monoclonal antibodies prepared to different proteins phosphorylated by the src tyrosine kinase, I have recently cloned cDNAs encoding eight cellular substrates, seven of which show no overall homology to sequences in international protein databases. I plan to focus on the characterization of a representative 120 kilodalton (kDa) protein (p120) whose phosphorylation in cells transformed by activated p60c-src, polyoma middle T antigen, and in response to stimulation of cells by epidermal growth factor (EGF), platelet-derived growth factor (PDGF), and colony-stimulating factor 1 (CSF-1) implies that it may play a central role in ligand-induced signaling and cell transformation. My goals are to complete the molecular characterization of p120 cDNA, to determine its subcellular topology and distribution among different cell types, and to biochemically map the major sites of tyrosine phosphorylation within the molecule. Using this information, I hope to develop model biological systems for defining the as yet unknown function of p120 and for determining the role of tyrosine phosphorylation in modifying its activity. In principle, the approaches that I envision should be applicable to the characterization of the other src substrates defined by my antibodies, and I will include experiments involving these proteins under circumstances where their comparison with p120 might prove particularly informative.

活化的受体和非受体蛋白酪氨酸激酶（PTK）是 假定是为了介导他们在信号转导和细胞中的各种效果 通过在酪氨酸上磷酸化细胞蛋白的转化，从而转化 修改其生化活动。 因为许多细胞底物 PTK的尚未分子表征，它们的功能仍然存在 未知，我们对中继PTK-的生化途径的理解 诱导信号仍然不完整。 该提议的中心主题是 表征新颖的PTK底物并确定其推定的 在信号转导和细胞转化中的作用。 使用单克隆 抗体准备由SRC磷酸化的不同蛋白质的抗体 酪氨酸激酶，我最近克隆了编码八个细胞的cDNA 底物，其中七个没有显示与序列的总体同源性 国际蛋白质数据库。 我计划专注于特征 120千达尔顿（KDA）蛋白（p120）的代表性 通过活化的p60c-SRC转化的细胞中的磷酸化，多瘤中间 t抗原，以及通过表皮生长刺激细胞的刺激 因子（EGF），血小板衍生的生长因子（PDGF）和菌落刺激 因子1（CSF-1）意味着它可能在配体诱导的 信号传导和细胞转换。 我的目标是完成分子 P120 cDNA的表征，以确定其亚细胞拓扑结构和 在不同的细胞类型之间分布，并在生化绘制主要 分子内酪氨酸磷酸化的位点。 使用此 信息，我希望开发模型的生物系统来定义AS 但是，P120的功能未知并确定酪氨酸的作用 修饰其活性时的磷酸化。 原则上，方法 我设想的应该适用于对方的特征 由我的抗体定义的SRC底物，我将包括实验 在与之比较的情况下涉及这些蛋白质 P120可能会特别有用。