SIGNAL TRANSDUCTION PATHWAYS AND POLYOMA MIDDLE T

信号转导途径和多发性中 T

• 批准号: 6269423
• 负责人: BRIAN S SCHAFFHAUSEN
• 金额: $ 27.41万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-06 至 1999-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6269423
• 关键词: G protein; Polyomavirus; alcohol phosphotransferase; biological signal transduction; cell growth regulation; chemical binding; enzyme activity; host organism interaction; immunoprecipitation; laboratory mouse; laboratory rabbit; laboratory rat; mutant; neoplastic transformation; oncoproteins; phosphorylation; protein sequence; protein structure function; site directed mutagenesis; tissue /cell culture; transforming virus; tumor antigens; viral carcinogenesis; virus antigen; virus protein

The overall goals are to understand pathways of cell growth regulation and to understand how polyomavirus subverts them to produce transformation. The work proposed here concerns signaling pathways employed for transformation by polyoma middle T antigen. It emphasizes the enzyme phosphatidylinositol-3'-kinase. Understanding PI-3'-kinase is essential not only because it appears critical for middle T transformation, but also because this enzyme has been implicated in growth regulation by other transforming genes and growth factor receptors. In this enzyme, the P110 subunit has catalytic activity, while the p85 subunit provides regulation. The p85 subunit contains SH2, SH3 and bcr domains. These elements are found in a wide variety of proteins involved in signal response. The results obtained for PI-3'- kinase will therefore be of general importance. Our specific goals are: A. Studies on regulation of PI-3'-kinase and its role in growth and transformation 1. Studies on sites of serine phosphorylation 2. Analysis of the effect of blocking PI-3'-kinase activation 3. Establishment of connections between PI-3'-kinase and other growth regulatory pathways B. Studies related to SH2 function 1. Random mutagenesis of SH2s to determine structure/function relationships 2. Determination of whether middle T binds simultaneously to more than one SH2 3. Test of the MXM hypothesis of SH2 specificity to see if a designed middle T mutant can bind a p85 with an appropriately altered specificity. 4. Determination of whether an additional SH2 interaction might be important for determining tumor profiles of hamster middle T. C. Studies related to SH3 function 1. Mutagenesis of the SH3 of PI-3'-kinase 2. Identification of proteins that bind p85 SH3 3. Mutagenesis of middle T in the region of dl 1015 4. Screening for interactions between middle T and other SH3s D. Studies of the interactions among small G-proteins, PI-3'-kinase and middle T 1. Determination of PI-3'-kinase rac/rho/cdc 42 interactions 2. Analysis of the role of rac/rho in polyoma transformation using dominant negatives.

总体目标是了解细胞生长调节途径 并了解多瘤病毒如何颠覆它们以产生 转变。 这里提出的工作涉及信号通路 用于多瘤中T抗原的转化。 它强调 磷脂酰肌醇-3'-激酶。 了解 PI-3'-激酶 至关重要，不仅因为它对中 T 至关重要 转化，还因为这种酶与 其他转化基因和生长因子的生长调节 受体。 在这种酶中，P110亚基具有催化活性， 而p85亚基则提供调节作用。 p85 亚基包含 SH2、 SH3 和 bcr 域。 这些元素存在于多种 参与信号反应的蛋白质。 PI-3'-获得的结果 因此，激酶具有普遍重要性。 我们的具体目标是： A. PI-3'-激酶的调控及其在生长发育中的作用研究 转变 1.丝氨酸磷酸化位点的研究 2. 阻断 PI-3'-激酶激活效果分析 3. PI-3'-激酶与其他生长之间联系的建立 监管途径 B. SH2功能相关研究 1. SH2 的随机诱变以确定结构/功能 关系 2. 确定中间T是否同时结合多个 一台SH2 3. 测试 SH2 特异性的 MXM 假设，看看设计是否有效 中间 T 突变体可以结合 p85，并适当改变 特异性。 4. 确定是否可能存在额外的 SH2 相互作用 对于确定仓鼠中 T 的肿瘤特征很重要。 C. SH3功能相关研究 1. PI-3'-激酶 SH3 的诱变 2. 结合 p85 SH3 的蛋白质的鉴定 3. dl 1015 区域中 T 的诱变 4. 筛选中间 T 与其他 SH3 之间的相互作用 D. 小G蛋白、PI-3'-激酶和小G蛋白之间相互作用的研究 中T 1. PI-3'-激酶 rac/rho/cdc 42 相互作用的测定 2. rac/rho在多瘤转化中的作用分析 显性阴性。