Regulation of Transcription and Translation by Human Polyomaviruses

人类多瘤病毒的转录和翻译调控

• 批准号: 8849838
• 负责人: JAMES M PIPAS
• 金额: $ 18.31万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8849838
• 关键词: Animals; Antigens; Antiviral Agents; Automobile Driving; Binding; Biological Assay; Cell Culture Techniques; Cell Cycle Arrest; Cell Death; Cell Proliferation; Cell physiology; Cells; ChIP-seq; Complex; Coupled; DNA Binding Domain; DNA biosynthesis; EP300 gene; Environment; Family; Gene Expression; Genes; Genetic Transcription; Health; Human; Infection; Investigation; Laboratory Animals; Large T Antigen; Messenger RNA; Monkeys; Nonstructural Protein; Oncogene Proteins; Pathway interactions; Polyomaviridae; Polyomavirus; Proliferating; Property; Protein p53; Proteins; Relative (related person); Retinoblastoma Protein; Ribosomes; Role; Series; Simian virus 40; Structural Protein; System; Testing; Transcriptional Regulation; Translations; Tumor Antigens; Viral; Viral Proteins; Viral Tumor Antigens; Virion; Virus; cdc Genes; cell transformation; cellular targeting; deep sequencing; ds-DNA; gain of function; member; mutant; novel strategies; prevent; promoter; protein function; research study; single molecule; transcriptome sequencing; tumor; tumorigenesis; viral DNA

DESCRIPTION (provided by applicant): Some members of the Polyomaviridae induce tumors in laboratory animals or in their natural hosts. In these cases, tumorigenesis in animals or transformation in cell culture requires the expression of one or more viral proteins called tumor antigens. The monkey virus SV40 and its close relatives BKV and JCV encode a large tumor antigen (LT) that acts as the main oncoprotein. Transformation and tumorigenesis induced by SV40 has been studied extensively and requires the interaction of LT with three types of cellular proteins: (1) the Rb-proteins (pRb, p107, and p130), hsc70, and p53. The association of SV40 LT with Rb-proteins, coupled with the action of hsc70, triggers E2F-dependent transcription of cell cycle genes and this action is sufficient to drive quiescent cells to proliferate. SV40 LT als binds to the DNA-binding domain of the cellular tumor suppressor p53 and thus inhibits its ability to bind and activate the promoters of p53-responsive genes. Consequently, the expression of cell-cycle arrest or cell death-inducing proteins is blocked. Like SV40, the LTs encoded by the human polyomaviruses BKV and JCV also bind and inhibit Rb-proteins and p53. However, these LTs induce transformation much less efficiently than SV40 LT. Several studies have suggested that the weaker transformation seen by BKV and JCV is due to lower transcription from the viral promoters. We have compared the transforming abilities of the SV40, BKV, and JCV LTs by driving their expression from the same common heterologous promoter. While BKV and JCV LTs accumulated to much lower steady state levels than SV40 LT, all three LTs were equally capable of disrupting the pRb pathway and inducing cell proliferation. However, BKV and JCV LTs transformed much less efficiently than SV40 LT in a number of assays. The amount of p53 - presumably bound and inactivated by each LT- varied considerably in each case and correlated to the amount of each specific LT present. We thus hypothesize that the increased transformation induced by SV40 is explained by a "gain-of-function" attributed to LT-p53 complexes. We predict that LT does not simply block the expression of p53-dependent genes - preventing p53 association with promoters - but that it also uses the p53 activation domain to stimulate the transcription of cellular genes thus contributing positively to transformation. We will test this hypothesis by a series of p53 ChIP-seq experiments. We also found that SV40 LT increases and controls the translation of the regulators CBP/p300, a function previously unknown to LT molecules. Because all SV40, BKV and JCV LT share a high degree of homology, we hypothesize that translational control is a common property of polyoma LTs. We will test this hypothesis by performing RNA-seq experiments on ribosome associated mRNAs. These studies will fill important gaps in our understanding of polyomavirus-induced tumorigenesis.

描述（由申请人提供）：多瘤病毒的一些成员在实验动物或其自然宿主中诱导肿瘤。在这些情况下，动物的肿瘤发生或细胞培养中的转化需要一种或多种称为肿瘤抗原的病毒蛋白的表达。猴子病毒SV40及其近亲BKV和JCV编码的大型肿瘤抗原（LT）充当主要的癌蛋白。 SV40诱导的转化和肿瘤发生已进行了广泛的研究，需要LT与三种类型的细胞蛋白相互作用：（1）RB蛋白质（PRB，P107和P130），HSC70和P53。 SV40 LT与RB蛋白的关联，再加上HSC70的作用，触发了细胞周期基因的E2F依赖性转录，并且该作用足以驱动静态细胞增殖。 SV40 LT ALS与细胞肿瘤抑制剂p53的DNA结合结构域结合，从而抑制其结合和激活p53响应基因启动子的能力。因此，细胞周期停滞或诱导细胞死亡的蛋白的表达被阻断。像SV40一样，由人类多瘤病毒BKV和JCV编码的LTS也结合并抑制RB蛋白质和p53。但是，这些LT诱导转化的效率远低于SV40 LT。几项研究表明，BKV和JCV看到的较弱的转化是由于病毒启动子的转录较低。我们通过从相同常见的异源启动子中推动其表达来比较了SV40，BKV和JCV LT的转换能力。尽管BKV和JCV LT累积到稳态水平远低于SV40 LT，但所有三个LT都能够破坏PRB途径并诱导细胞增殖。但是，在许多测定中，BKV和JCV LTS的变化效率要比SV40 LT的效率差得多。 p53的量 - 大概是在每种情况下被每个LT造成的，并且与存在的每个特定LT的量相关。因此，我们假设SV40引起的增加的转化是由归因于LT-P53复合物归因的“功能获得”来解释的。我们预测LT不仅会阻止p53依赖性基因的表达 - 防止p53与启动子的关联 - 而且还使用p53激活结构域来刺激细胞基因的转录，从而对转化产生了积极影响。我们将通过一系列p53 CHIP-seq实验来检验这一假设。我们还发现，SV40 LT增加并控制了调节剂CBP/P300的翻译，这是LT分子以前未知的函数。由于所有SV40，BKV和JCV LT具有高度同源性，因此我们假设翻译控制是多头LT的共同特性。我们将通过对核糖体相关mRNA进行RNA-Seq实验来检验该假设。这些研究将填补我们对多瘤病毒诱导的肿瘤发生的重要空白。

项目成果

The Ancient Evolutionary History of Polyomaviruses.

• DOI: 10.1371/journal.ppat.1005574
• 发表时间: 2016-04
• 期刊: PLoS pathogens
• 影响因子: 6.7
• 作者: Buck CB;Van Doorslaer K;Peretti A;Geoghegan EM;Tisza MJ;An P;Katz JP;Pipas JM;McBride AA;Camus AC;McDermott AJ;Dill JA;Delwart E;Ng TF;Farkas K;Austin C;Kraberger S;Davison W;Pastrana DV;Varsani A
• 通讯作者: Varsani A