STRUCTURAL CHARACTERIZATION OF PUTATIVE GROWTH FACTOR RECEPTOR GENE C-ERB-2

假定的生长因子受体基因 C-ERB-2 的结构特征

• 批准号: 3916844
• 负责人: S A AARONSON
• 金额: --
• 依托单位: DIVISION OF CANCER EPIDEMIOLOGY AND GENETICS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3916844
• 关键词: biological signal transduction; chemical structure function; epidermal growth factor; gene deletion mutation; gene expression; genetic manipulation; growth factor; growth factor receptors; membrane activity; molecular biology; molecular cloning; neoplasm /cancer genetics; neoplastic transformation; oncogenes; oncoproteins; phosphorylation; point mutation; protein sequence; protein tyrosine kinase; site directed mutagenesis; transfection

In order to study the molecular mechanisms involved in signal transduction and regulation of the catalytic activity of the erbB- 2 receptor protein, a series of mutants in different structural domains of the gene product were generated. Mutated molecular clones were expressed into NIH/3T3 cells in order to assess their biologic activity in a focus assay. We found that two different classes of structural alterations, i.e., an NH-2 terminal deletion and a Val 659 to Glu or Val 659 to Asp mutation, are capable of upregulating the transforming potential of the erbB-2 product. Mutant proteins exhibit an increased level of in vitro tyrosine kinase activity as well as an increased level of in vivo phosphorylation on tyrosine residues. These results indicate that deregulated tyrosine kinase function is a major determinant of erbB-2 receptor oncogenic activity. We are currently investigating the role of tyrosine autophosphorylation in the modulation of the erbB-2 receptor catalytic activity by analyzing the biological and biochemical behavior of mutant proteins lacking one or more of the tyrosine residues which are believed to be targets of autophosphorylation.

为了研究参与信号传导的分子机制， erbB-2基因的转录和调控 2受体蛋白，一系列不同结构的突变体， 产生基因产物的结构域。 突变分子 将克隆表达到NIH/3 T3细胞中，以评估其 在焦点测定中的生物活性。 我们发现两种不同的 结构改变的类别，即，NH-2末端缺失 和瓦尔659突变为Glu或瓦尔659突变为Asp，能够 上调erbB-2产物的转化潜力。 突变蛋白表现出体外酪氨酸水平的增加 激酶活性以及体内 酪氨酸残基的磷酸化。 这些结果表明 酪氨酸激酶功能失调是一个主要的决定因素， erbB-2受体致癌活性。 我们目前正在调查 酪氨酸自身磷酸化在调节细胞内的 erbB-2受体催化活性，通过分析生物学和 缺乏一种或多种生物化学活性的突变蛋白的生物化学行为 酪氨酸残基被认为是 自磷酸化