TRANSLATIONAL CONTROL OF CYTOMEGALOVIRUS GENE EXPRESSION

本研究的目的是阐明人巨细胞病毒（CMV）基因表达的顺式作用信号，鉴定反式作用因子，并在翻译水平上阐明调控CMV基因表达的机制。 CMV翻译控制的分子基础的调查将揭示两个病毒特异性的过程，可能有用的抗病毒干预措施的目标，以及新的见解真核细胞翻译的基本原理。 该项目的重点是CMV gpUL 4蛋白，其合成受gpUL 4 mRNA中的短上游开放阅读框（uORF 2）的调控。 突变病毒将用于评价uORF2改变对gpUL4表达调控和病毒复制的影响。 结合异位gpUL4的后果的调查，这些研究将阐明gpUL4的翻译调控在病毒生命周期中的意义。 第二系列的实验将阐明uORF2调控基因表达的详细分子机制。 遗传学研究使用S. cerevisaie，辅以哺乳动物细胞和细胞提取物中的分子生物学和生物化学测定，将描绘由uORF2控制的翻译终止期间的精确步骤，并将鉴定参与这种特殊调节机制的反式作用因子。

The goals of this research are to delineate the cis-acting signals, identify the trans-acting factors and elucidate the mechanisms that regulate human cytomegalovirus (CMV) gene expression at the translational level. Investigations of the molecular basis of CMV translational control will reveal both viral-specific processes, potentially useful as targets for antiviral interventions, as well as new insights into fundamentals of eukayrotic translation. This project focuses on the CMV gpUL4 protein, synthesis of which is regulated by a short upstream open reading frame (uORF2) in the gpUL4 mRNA. Mutant viruses will be used to evaluate the effects of uORF2 alterations on regulation of gpUL4 expression and on viral replication. In conjunction with investigations of the consequences of ectopic gpUL4, these studies will illuminate the significance of gpUL4 translational regulation in the viral life cycle. A second series of experiments will elucidate the detailed molecular mechanism by which uORF2 regulates gene expression. Genetic studies using S. cerevisaie, complemented by molecular biological and biochemical assays in mammalian cells and cell extracts will delineate the precise step during translation termination that is controlled by uORF2 and will identify trans-acting factors that participate in this extraordinary regulatory mechanism.