Modulation of Oncogenesis by E1A--Role of CtBP and CtIP

E1A 对肿瘤发生的调节——CtBP 和 CtIP 的作用

• 批准号: 6710037
• 负责人: GOVINDASWAMY CHINNADURAI
• 金额: $ 22.62万
• 依托单位: SAINT LOUIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6710037
• 关键词: Adenoviridae; athymic mouse; binding proteins; cell transformation; enzyme activity; gamma radiation; gene mutation; genetic transcription; matrix assisted laser desorption ionization; metastasis; neoplasm /cancer genetics; nuclear proteins; oncoproteins; phosphoproteins; protein kinase; protein protein interaction; radiation genetics; retinoblastoma protein; transcription factor; viral carcinogenesis; virus genetics; virus protein; western blottings

DESCRIPTION: (Adapted from the Investigator's abstract): The second exon of adenovirus EIA negatively modulates in vitro cell transformation, tumorigenesis and tumor metastasis. These activities of exon 2 are encoded within a short region located near the C-terminus of BIA. Mutations within this region confer a hyper-transforming phenotype on EIA. The oncogenesis restraining activities of the C-terminal region of EIA correlate with the interaction of a 48 kDa cellular nuclear protein, CtBP. CtBP is a transcriptional co-repressor. Through mutational analysis, we will determine if the oncogenesis modulating activity of CtBP is linked to its transcriptional repressor activity. CtBP also interacts with a cellular protein CtIP via a CtBP-binding motif, PLDLS. Our hypothesis predicts that interaction of CtIP with CtBP antagonizes the activities of CtBP and that the C-termninus of EIA may suppress tumorigenesis by disrupting the CtBP/CIIP complex. We hypothesize that the activity of a cellular repressor that functions through the CtBP corepressor may be altered by CtIP or E1A exon 2. We will determine the effects of overexpression of CtIP or EtA on the activity of a model human cellular repressor ZEB. CtBP is a phosphoprotein. We will identify the phosphorylation sites and investigate the role of phosphorylation on CtBP functions. In preliminary studies, we have observed that CtBP interacts with the p70 subunit of DNA-dependent protein kinase (DNA-PK). We will determine if CtBP is a target for DNA-PK. Our hypothesis predicts that an oncogenic stimulus would enhance complex formation between CtBP and CtIP. We will test this hypothesis by analyzing the CtBP/CtIP complex by coimmunoprecipitation analysis in cells expressing EtA exon 1. CtIP also interacts with pRb-family tumor suppressor proteins (pRb, p107 and p130) through an Rb-binding site (LXCXE). We hypothesize that the CR2 region ofElA promotes oncogenesis through a novel pathway (in addition to the previously known pRb/E2F pathway) by disrupting complexes of CtIP and pRb-famity proteins. We propose to investigate if the CR2 region of E1A disrupts the pRb/CtIP complex in vivo and leads to oncogenic transformation in cooperation with E2F-l. Thus, our proposed studies should illuminate how a viral oncoprotein, adenovirus EtA, modulates oncogenesis novel pathways that involve cellular proteins CtBP and CtIP.

描述：（根据调查人员的摘要进行了改编）： 腺病毒EIA负面调节体外细胞转化，肿瘤发生 和肿瘤转移。外显子2的这些活动在简短的一小段内编码 位于BIA的C末端附近的地区。该区域内的突变 EIA上的超变形表型。肿瘤发生限制活动 EIA的C末端区域与48 kDa的相互作用相关 细胞核蛋白，CTBP。 CTBP是转录共抑制剂。通过 突变分析，我们将确定肿瘤发生是否调节活性 CTBP的转录阻遏活性链接。 CTBP也是如此 通过CTBP结合基序PLDL与细胞蛋白CTIP相互作用。我们的 假设预测，CTIP与CTBP的相互作用会拮抗 CTBP的活动和EIA的C-Termninus可能抑制肿瘤发生 通过破坏CTBP/CIIP复合物。我们假设 可以改变通过CTBP Corepressor功能的细胞阻遏物 由CTIP或E1A外显子2。我们将确定CTIP过表达的影响 或ETA对模型人类细胞阻遏ZEB的活性。 CTBP是一个 磷蛋白。我们将确定磷酸化位点并研究 磷酸化对CTBP功能的作用。在初步研究中，我们有 观察到CTBP与DNA依赖性蛋白的p70亚基相互作用 激酶（DNA-PK）。我们将确定CTBP是否是DNA-PK的靶标。我们的 假设预测致癌刺激将增强复合形成 在CTBP和CTIP之间。我们将通过分析CTBP/CTIP来检验这一假设 通过表达ETA外显子1。CTIP的细胞中的共免疫沉淀分析复合物 还与PRB - 家庭肿瘤抑制蛋白相互作用（PRB，P107和P130） 通过RB结合位点（LXCXE）。我们假设CR2区域 通过一种新的途径促进造成发生（除了先前 通过破坏CTIP和PRB - 家庭蛋白的复合物，已知的PRB/E2F途径）。 我们建议研究E1A的CR2区域是否破坏PRB/CTIP 复杂体内，并与 E2F-L。因此，我们提出的研究应阐明病毒癌蛋白如何 腺病毒ETA，调节肿瘤发生新型途径，涉及细胞 蛋白质CTBP和CTIP。