PROCESSING AND FUNCTION OF POLYOMA RNA

致癌多瘤小鼠病毒为我们提供了一个很好的模型系统 不仅研究细胞转化的分子生物学， 肿瘤发生，而且真核基因的调控机制 表情我们的主要兴趣是更好地了解病毒 RNA分子在受感染的细胞中产生和加工， 关注于后链RNA。我们特别感兴趣的是 和晚期启动子的调控，晚期前mRNA的加工， 在病毒DNA起始之前从大部分早链MRNAS转换 之后合成为大部分后链MRNAS。主要项目将 是在体内和体外解剖晚期启动子。该启动子 属于引发剂类的促进剂。的特定序列 重要的是它的功能将被确定，和因素调节 其活性将被鉴定、纯化和克隆。晚期病毒RNA 加工涉及外显子跳跃，以及选择性选择， 3'剪接位点。剪接位点使用的调节机制 将通过研究大量的突变体和双- 基因组构建体。基因技术也将被用来学习如何 一些未剪接的晚期MRNAS在细胞核和细胞质中积累， 被感染的细胞最后，将进行研究，以了解 调节早迟开关。DNA复制的影响，大T 抗原、启动子序列和多聚腺苷酸化位点序列， 早链和晚链RNA的相对积累将是 测定各种模型，可以解释开关将被测试， 其中包括早链RNA在晚期下调 通过产生大量的巨大的后链转录本， 形成反义杂交体

The oncogenic polyoma mouse virus provides us with a good model system for studying not only the molecular biology of cell transformation and tumorigenesis, but also mechanisms of regulation of eukaryotic gene expression. Our primary interests are in better understanding how viral RNA molecules are made and processed in infected cells, with a major focus on late-strand RNAs. Our particular interests are the structure and regulation of the late promoter, late pre-MRNA processing, and the switch from mostly early-strand MRNAS before the initiation of viral DNA synthesis to mostly late-strand MRNAS afterwards. The major project will be to dissect the late promoter both in vivo and in vitro. This promoter belongs to the initiator class of promoters. Specific sequences that are important for its function will be determined, and factors regulating its activity will be identified, purified and cloned. Late viral RNA processing involves exon skipping, as well as alternative selection of 3' splice sites. The mechanism by which splice site use is regulated will be determined through the study of numerous mutants and double- genome constructs. Genetic techniques will also be used to learn how some unspliced late MRNAS accumulate in the nucleus and cytoplasm of infected cells. Finally, studies will be carried out to learn what regulates the early-late switch. Effects of DNA replication, large T antigen, promoter sequences and polyadenylation site sequences on the relative accumulation of early-strand and late-strand RNAs will be determined. Various models that can explain the switch will be tested, including one in which early-strand RNA is downregulated at late times by the production of large amounts of giant late-strand transcripts that form antisense hybrids with them.