Products of the Transforming Genes of Polyomavirus

多瘤病毒转化基因产物

• 批准号: 6989675
• 负责人: BRIAN S SCHAFFHAUSEN
• 金额: $ 33.85万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-27 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6989675
• 关键词: Polyomavirus muris 1; binding proteins; gene expression profiling; guanosinetriphosphatase activating protein; guanosinetriphosphatases; human tissue; laboratory mouse; laboratory rabbit; metastasis; neoplasm /cancer genetics; neoplastic transformation; osteopontin; phosphatidylinositol 3 kinase; protein sequence; tumor antigens; viral carcinogenesis; virus genetics

Murine polyomavirus provides a valuable model for neoplastic transformation. The virus causes a broad spectrum of tumors in animals. This means that leads developed in the laboratory can be readily tested in the host. Studies on polyoma have repeatedly provided insight into basic mechanisms of cellular growth regulation. Tyrosine kinase signaling and phosphatidylinositol 3-kinase (PI3K) signaling are two fundamental mechanisms uncovered from studies on polyoma. Middle T antigen (MT) is the major transforming protein of polyomavirus. It is always necessary, and often sufficient, for cellular transformation by polyoma. This subproject will extend our knowledge of MT and its signaling based on leads developed in the previous project period. There are 4 specific aims. 1) We have shown that MT activates the small GTPase Ral. We will examine how MT activates Ral. We will test the role of Ral in MT transformation. Since Ral functions in trafficking processes including secretion, we will test MT function there. 2) MT induces osteopontin, a secreted protein thought to be linked to transformation and metastasis. We will determine how MT regulates osteopontin. We will determine the role of osteopontin in MT transformation by examining tumor profiles. Using breast cancer and hemangioma models, we will test the role of osteopontin in metastasis and in cell recruitment. We will initiate structural analysis of MT using NMR to determine the structure of the portion of MT that interacts with downstream targets such as Shc and PI3K. We will then map the interaction surface between MT and p85 of PI3K or Shc. Finally, there is strong genetic evidence suggesting that there are undiscovered MT binding proteins. We will use tandem affinity purification and mass spectrometry to identify them. We will determine the MT sequences required for their interaction. We will test their function in MT assays for transformation.

鼠多瘤病毒为肿瘤转化提供了有价值的模型。该病毒在动物中引起广泛的肿瘤。这意味着实验室开发的先导化合物可以很容易地在宿主中进行测试。对多瘤的研究多次提供了对细胞生长调节基本机制的见解。酪氨酸激酶信号传导和磷脂酰肌醇 3 激酶 (PI3K) 信号传导是多瘤研究中发现的两个基本机制。中T抗原(MT)是多瘤病毒的主要转化蛋白。对于多瘤细胞转化来说，它始终是必要的，而且通常是足够的。该子项目将基于上一个项目期间开发的线索扩展我们对机器翻译及其信号传导的了解。有4个具体目标。 1) 我们已经证明 MT 激活小 GTPase Ral。我们将研究 MT 如何激活 Ral。我们将测试Ral在MT转换中的作用。由于 Ral 在包括分泌在内的运输过程中发挥作用，我们将在那里测试 MT 功能。 2) MT 诱导骨桥蛋白，一种被认为与转化和转移有关的分泌蛋白。我们将确定 MT 如何调节骨桥蛋白。我们将确定骨桥蛋白的作用 通过检查肿瘤概况来进行 MT 转化。使用乳腺癌和血管瘤模型，我们将测试骨桥蛋白在转移和细胞募集中的作用。我们将使用 NMR 启动 MT 的结构分析，以确定 MT 与 Shc 和 PI3K 等下游靶点相互作用的部分的结构。然后我们将绘制 MT 和 PI3K 或 Shc 的 p85 之间的相互作用表面。最后，有强有力的遗传证据表明存在尚未发现的 MT 结合蛋白。我们将使用串联亲和纯化和质谱法来鉴定它们。我们将确定它们相互作用所需的 MT 序列。我们将在 MT 转化分析中测试它们的功能。