Gaynor R B, Berk A J
Cell. 1983 Jul;33(3):683-93. doi: 10.1016/0092-8674(83)90011-9.
At early times after adenovirus infection, transcription from all early viral promoters requires the expression of a 289 amino acid phosphoprotein encoded in the pre-early transcription unit E1A. Mutations in E1A result in a marked delay in the induction of early viral transcription. To distinguish between possible models that could account for this delayed transcription, superinfection experiments were performed. Cells were first infected with one E1A mutant, incubated until viral transcription was detectable, and then superinfected with a second E1A mutant with distinguishable transcripts from early region 3 (E3). We found that the second virus to infect the cell recapitulated the delayed transcription induction of E3. Therefore, the delayed expression of early regions after infection with E1A mutants is the result of a time-dependent cis-acting modification of the template. Models which can account for these observations and for the function of E1A protein are discussed.
在腺病毒感染后的早期，所有早期病毒启动子的转录都需要表达一种由早期转录单位E1A编码的289个氨基酸的磷蛋白。E1A中的突变会导致早期病毒转录诱导的显著延迟。为了区分可能解释这种延迟转录的模型，进行了超感染实验。细胞首先用一种E1A突变体感染，孵育至可检测到病毒转录，然后用来自早期区域3（E3）的具有可区分转录本的第二种E1A突变体进行超感染。我们发现，第二种感染细胞的病毒重现了E3延迟转录诱导的情况。因此，用E1A突变体感染后早期区域的延迟表达是模板的时间依赖性顺式作用修饰的结果。讨论了能够解释这些观察结果以及E1A蛋白功能的模型。
