Venkatesh L K, Chinnadurai G
Nucleic Acids Res. 1987 Mar 11;15(5):2235-50. doi: 10.1093/nar/15.5.2235.
We have studied the effect of template replication on transcriptional activation of the promoters for the adenoviral protein IX and E1a genes using a short-term transient expression assay. DNA replication mediated modulation of the transcriptional activity of these promoters was monitored using plasmids with limited replication capability conferred by the SV40 minimal origin of DNA replication in the monkey kidney cell line, COS M6. Our results indicate a substantial increase in protein IX promoter directed transcription in a dosage-independent manner as a consequence of the DNA replication process. In contrast, the transcriptional activity of the adenovirus 2 E1a promoter was not significantly altered. In addition to this DNA replication-mediated effect, transcription from the protein IX promoter was positively regulated by the adenovirus E1a 13S and E4 gene products but was repressed by the E1a 12S gene product to a limited extent. The evidence suggests that the effect of template replication on the transcriptional activity of plasmid-borne protein IX and E1a gene promoters in this transient expression system closely mimics the situation on the viral chromosome.
我们使用短期瞬时表达测定法，研究了模板复制对腺病毒蛋白IX和E1a基因启动子转录激活的影响。在猴肾细胞系COS M6中，利用具有由SV40最小DNA复制起点赋予的有限复制能力的质粒，监测DNA复制介导的这些启动子转录活性的调节。我们的结果表明，作为DNA复制过程的结果，蛋白IX启动子指导的转录以剂量非依赖性方式大幅增加。相比之下，腺病毒2 E1a启动子的转录活性没有显著改变。除了这种DNA复制介导的效应外，蛋白IX启动子的转录受到腺病毒E1a 13S和E4基因产物的正向调节，但在一定程度上受到E1a 12S基因产物的抑制。证据表明，在这个瞬时表达系统中，模板复制对质粒携带的蛋白IX和E1a基因启动子转录活性的影响与病毒染色体上的情况非常相似。
