Role of p300/CBP in SV40 Large T Antigen Transformation

p300/CBP 在 SV40 大 T 抗原转化中的作用

• 批准号: 6792489
• 负责人: DARRELL R BORGER
• 金额: $ 4.89万
• 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: 2004-05-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6792489
• 关键词: acetylation; acyltransferase; athymic mouse; carcinogenesis; molecular cloning; neoplasm /cancer genetics; neoplastic transformation; oncoproteins; p53 gene /protein; postdoctoral investigator; posttranslational modifications; protein binding; protein protein interaction; protein structure function; tissue /cell culture; transcription factor; tumor antigens

DESCRIPTION (provided by applicant): This proposed project will examine whether activities of p300 and CBP contribute to the transforming function of SV40 large T antigen (LT). A requirement for p300/CBP association with LT will be studied using a model of human carcinogenesis. In this multi-step system, expression of LT and the active telomerase subunit promotes immortalization. Full tumorigenic conversion is then conferred through expression of H-Ras and SV40 small T antigen. Since LT activity is required for the initial steps of transformation, this provides an excellent model to expand current understanding of cellular pathways targeted by LT. We have identified an interaction between LT and the p300/CBP transcriptional coactivators and implicate a bridging function of p53. Our first goal is to determine whether the acetylation of LT that we have found under cellular conditions can be attributed to p300/CBP binding and whether this requires an intermediary role of p53. This will be addressed using p53-/- MEF cells or purified proteins. We will then determine whether p300/CBP activity contributes to the overall transforming properties of LT. The use of competitive p300 fragments to disrupt LT binding to endogenous p300/CBP, with or without a fused acetyltransferase domain, will be used to determine whether LT binding recruits p300/CBP acetyltransferase activity or sequesters p300/CBP from normal cellular targets. Finally, we will determine whether the stabilization of inactive p53 can further contribute to the transformation process through a gain of function that serves to sequester p300/CBP from normal cellular functioning.

描述（由申请人提供）：本拟议项目将检查p300和CBP的活性是否有助于SV40大T抗原（LT）的转化功能。将使用人类致癌模型来研究 p300/CBP 与 LT 相关性的要求。在这个多步骤系统中，LT 和活性端粒酶亚基的表达促进永生化。然后通过 H-Ras 和 SV40 小 T 抗原的表达实现完全致瘤转化。由于转化的初始步骤需要 LT 活性，因此这提供了一个极好的模型来扩展当前对 LT 靶向细胞途径的理解。我们已经确定了 LT 和 p300/CBP 转录共激活因子之间的相互作用，并暗示了 p53 的桥接功能。我们的首要目标是确定我们在细胞条件下发现的 LT 乙酰化是否可归因于 p300/CBP 结合，以及这是否需要 p53 的中介作用。这将使用 p53-/- MEF 细胞或纯化的蛋白质来解决。然后我们将确定 p300/CBP 活性是否有助于 LT 的整体转化特性。使用竞争性 p300 片段破坏 LT 与内源性 p300/CBP 的结合（无论有或没有融合的乙酰转移酶结构域），将用于确定 LT 结合是否会招募 p300/CBP 乙酰转移酶活性或将 p300/CBP 与正常细胞靶标隔离。最后，我们将确定失活的 p53 的稳定是否可以通过功能的获得进一步促进转化过程，从而将 p300/CBP 与正常细胞功能隔离。