NOVEL CELL CYCLE REGULATION BY ADENOVIRUS E1B 55K

腺病毒 E1B 55K 对细胞周期的新型调控

• 批准号: 6376678
• 负责人: David Arnold Ornelles
• 金额: $ 22.75万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6376678
• 关键词: Adenoviridae; cell cycle; flow cytometry; gene mutation; genetic transcription; intracellular transport; messenger RNA; oncoproteins; protein structure function; tissue /cell culture; transmission electron microscopy; viral carcinogenesis; virus RNA; virus infection mechanism; virus protein

The adenovirus E1B 55-kDa (55K) protein functions during virus growth and virus-mediated cellular transformation. During virus growth, the 55K protein binds the E4orf6 protein and regulates mRNA biogenesis. During transformation, the 55K protein binds the tumor suppressor p53 and blocks transcription from p53-responsive genes including those that promote apoptosis and induce G1 growth arrest. However, most cells infected with the 55K-mutant virus do not undergo apoptosis, do not arrest in G1, and do not fail to replicate mutant viral DNA. Consequently, the link between 55K function in virus growth and transformation remains unclear. This work will elucidate this link as part of the larger goal of understanding the means by which adenovirus targets mechanisms of cellular growth control for virus growth. Because 55K-mutant viruses grow only in HeLa cells that were infected in early S phase but not in G1, the 55K protein overcomes a restriction imposed on virus growth by the cell cycle. This restriction and the 55K function that overcomes this restriction will be determined by three specific aims. First, the hypothesis that adenovirus must usurp the control of mRNA for cell cycle-independent growth will be evaluated by comparing the growth of related G1-restricted adenovirus mutants and the control of mRNA transport among infected cells that are permissive and restrictive for virus growth. Second, heterokaryons of permissive and restrictive cells will be used to elucidate the cellular basis for this restriction and determine the dominance of the restrictive phenotype. Third, cellular proteins targeted by 55K/E4orf6 complex for cell cycle-independent virus growth will be identified and the cell cycle- regulation of these proteins determined. This study will determine how the 55K protein subverts cell cycle controls for virus growth. This may represent the first link between the roll of the 55K protein in lytic growth and viral transformation. These studies will increase our understanding of the mechanisms of viral pathogenesis and viral oncogenesis as well as fundamental mechanisms of cellular growth control. Furthermore, this study will identify adenovirus mutants that are restricted for growth in S phase cells. Such replication competent viruses can be used as oncolytic agents to treat rapidly growing human tumors.

在病毒生长和病毒介导的细胞转化过程中，腺病毒E1b 55-kDA（55K）蛋白功能。 在病毒生长过程中，55K蛋白结合E4ORF6蛋白并调节mRNA生物发生。在转化过程中，55K蛋白结合肿瘤抑制p53，并阻止p53响应基因的转录，包括促进凋亡并诱导G1生长停滞的基因。 然而，大多数感染55K突变病毒的细胞不会发生凋亡，不要在G1中停滞，并且不会复制突变的病毒DNA。因此，病毒生长和转化中55K功能之间的联系尚不清楚。 这项工作将阐明这一联系，这是理解腺病毒靶向病毒生长机制机制的更大目标的一部分。由于仅在S期感染但不在G1中感染的HeLa细胞中生长55K突变病毒，因此55K蛋白克服了对病毒生长在细胞周期中施加的限制。 克服该限制的限制和55K函数将由三个特定目标确定。 首先，将通过比较相关的G1限制性腺病毒突变体的生长以及对病毒生长的受感染细胞的控制，并控制了相关的G1限制性腺病毒突变体的生长以及对病毒生长的受感染细胞中mRNA转运的控制，从而评估了腺病毒必须篡改mRNA对细胞周期非依赖性生长的控制的假设。 其次，将使用允许和限制性细胞的异质核心来阐明该限制的细胞基础，并确定限制性表型的优势。第三，将确定由55K/E4ORF6复合物靶向细胞周期非依赖病毒生长的细胞蛋白，并确定这些蛋白质的细胞周期调节。这项研究将确定55K蛋白如何颠覆病毒生长的细胞周期控制。 这可能代表55K蛋白在裂解生长和病毒转化中的第一个联系。这些研究将增加我们对病毒发病机理和病毒肿瘤发生机制以及细胞生长控制的基本机制的理解。此外，这项研究将确定腺病毒突变体受到S相细胞生长的限制。 这种复制能力的病毒可以用作肿瘤剂，以治疗快速生长的人类肿瘤。