VIRAL SMALL RNPS--ROLES IN CELL TRANSFORMATION

病毒小 RNPS——在细胞转化中的作用

• 批准号: 6268827
• 负责人: JOAN A. STEITZ
• 金额: $ 16.76万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-05-01 至 1999-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6268827
• 关键词: Epstein Barr virus; cell cycle; genetic translation; messenger RNA; molecular cloning; neoplasm /cancer genetics; nucleic acid sequence; ribonucleoproteins; ribosomal proteins; transfection /expression vector; viral carcinogenesis; virus protein

Small RNPs present in cells transformed by certain primate Herpesviruses are assembled from virus-encoded small RNAs and host protein components. The two EBERs (Epstein Barr encoded RNAS) of EBV tightly bind the cellular lupus antigen La (50 kd), while the four newly discovered HSURs (Herpes saimiri U-like RNAS) acquire 5'-m3G caps and associate with proteins common to the snRNPs responsible for splicing and other premessenger RNA processing reactions in mammalian cell nuclei. Both the EBERs and HSURs are localized in the nucleus and are among the few viral gene products expressed in transformed lymphocytes. Our long term goals are to understand how these viral small RNPs contribute to the transformed state and how t cell in turn controls their biogenesis. To achieve these goals we propose the following strategies: 1) We will ask, using in fl= assays and immunoprecipitation, whether EBERs might regulate the activity of the interferon-induced 2',5'-oligoA synthetase, since they do not have the same inhibitory effect as VAI on the activity of the interferon-induced protein kinase. We will construct EBER affinity columns to identify and subsequently characterize nuclear proteins that bind EBERS. 2) We will ask whether the high abundance of EBERs in EBV-transformed cells serves to ' maintain high levels of important cellular small RNAs (tRNAs, 5S) because of the sequestration of a large fraction of the cellular La protein. We will further probe La's function in transcription termination in vitro. 3) We will identify and characterize the transcription factors that bind to regulatory sequences upstream of the EBER genes (and the genes for HVP1 and 2 RNAs of Herpesvirus papio). Those that are also involved in transcription of cellular and viral oncogenes will be studied to ascertain co-regulation by phosphorylation, extracellular signals, protein interaction, etc. 4) The function of HSURs will be probed based on the assumption that they act in polyadenylation. Long-elusive comparable host-RNAs will be sought using HSUR probes. 5) Other primate Herpesviruses will be examined for the presence of novel small RNAs using various patient autoantibodies.

某些灵长类疱疹病毒转化的细胞中存在小 RNP 由病毒编码的小RNA和宿主蛋白成分组装而成。 EBV 的两个 EBER（Epstein Barr 编码的 RNAS）与细胞紧密结合 狼疮抗原La（50 kd），而四种新发现的HSUR（疱疹 saimiri U-like RNAS) 获得 5'-m3G 帽并与常见蛋白质结合 负责剪接的 snRNP 和其他前信使 RNA 哺乳动物细胞核中的加工反应。 EBER 和 HSUR 都是 定位于细胞核，是少数病毒基因产物之一 在转化的淋巴细胞中表达。我们的长期目标是了解 这些病毒小 RNP 如何促成转化状态以及如何 细胞反过来控制它们的生物发生。 为了实现这些目标，我们提出以下策略： 1) 我们将 询问，在 fl= 测定和免疫沉淀中使用，EBER 是否可能 调节干扰素诱导的 2',5'-oligoA 合成酶的活性， 因为它们对活性的抑制作用与 VAI 不同。 干扰素诱导的蛋白激酶。我们将构建EBER亲和力 用于识别并随后表征核蛋白的色谱柱 绑定 EBERS。 2）我们会问是否EBERs的高丰度 EBV 转化细胞有助于“维持高水平的重要 细胞小RNA（tRNA，5S），因为大分子的隔离 细胞 La 蛋白的一部分。我们将进一步探讨 La 的功能 体外转录终止。 3）我们将识别并表征 与上游调控序列结合的转录因子 EBER 基因（以及狒狒疱疹病毒 HVP1 和 2 RNA 的基因）。那些 也参与细胞和病毒癌基因的转录 将进行研究以确定磷酸化的共同调节， 细胞外信号、蛋白质相互作用等。 4）HSUR的功能 将基于它们在聚腺苷酸化中发挥作用的假设进行探讨。 将使用 HSUR 探针寻找长期难以捉摸的可比宿主 RNA。 5） 将检查其他灵长类疱疹病毒是否存在新型病毒 使用各种患者自身抗体的小 RNA。