Laboratory of Biochemistry, Garrett-Strong Science Building 3100, Northwest Missouri State University, Maryville, MO 64468, USA.
Plasmid. 2013 May;69(3):223-30. doi: 10.1016/j.plasmid.2013.01.004. Epub 2013 Feb 1.
Viral promoters are widely utilized in commercial and customized vectors to drive expression of genes of interest including reporter, effector and transfection control, because of their high transcription efficiency in a variety of primary and transformed cell lines. However, we observed altered rate of transcription for these promoters under conditions such as presence of an effector protein. These variations in viral promoter driven expressions can potentially lead to incorrect conclusion, especially in comparative and quantitative experiments. We found significantly reduced viral promoter activity in cells overexpressing tumor suppressor protein p53, whereas markedly induced transcription in cells overexpressing MAP/ERK kinase kinase 1 (Mekk 1). Using deletion constructs generated from the CMV promoter, we found the transcription reduction by p53 is possibly mediated through the TATA motif present in proximal CMV promoter. The activation of the CMV promoter by Mekk 1, on the other hand, is attributed to the proximal CRE binding site in the promoter. These findings may be of interest to investigators who use CMV (or other viral) promoter driven vectors for either comparative or quantitative gene expression, or effect on promoter activity.
病毒启动子被广泛应用于商业和定制载体中，以驱动目的基因（包括报告基因、效应基因和转染对照基因）的表达，这是因为它们在多种原代和转化细胞系中具有很高的转录效率。然而，我们观察到这些启动子在存在效应蛋白等条件下的转录速率发生了改变。这些病毒启动子驱动表达的变化可能会导致错误的结论，尤其是在比较和定量实验中。我们发现，在过度表达肿瘤抑制蛋白 p53 的细胞中，病毒启动子的活性显著降低，而在过度表达丝裂原活化蛋白激酶/细胞外信号调节激酶激酶 1（Mekk1）的细胞中，转录明显增加。使用从 CMV 启动子生成的缺失构建体，我们发现 p53 介导的转录减少可能是通过存在于近端 CMV 启动子中的 TATA 基序。另一方面，Mekk1 对 CMV 启动子的激活归因于启动子中近端 CRE 结合位点。这些发现可能对使用 CMV（或其他病毒）启动子驱动载体进行比较或定量基因表达或对启动子活性有影响的研究人员有兴趣。
