May E, Omilli F, Borde J, Scieller P
Centre National de la Recherche Scientifique, UPR 275, Villejuif, France.
J Virol. 1992 Jun;66(6):3347-54. doi: 10.1128/JVI.66.6.3347-3354.1992.
Late promoter activity measured before viral DNA replication results from a complex involvement of negative and positive cis-acting elements located both in the enhancer and in the 21-bp repeats. GC motifs located within the 21-bp repeats act in cooperation with sequences overlapping the early TATA box to down-regulate the late promoter activity. Analysis of insertion mutants indicates that the late promoter might be negatively regulated at least partially by the early promoter machinery. The GTI motif located within the enhancer as well as the GC motifs lose the ability to down-regulate the late promoter in the presence of T antigen. Results obtained with tsA58 protein indicate that two different domains of T antigen are involved in the negative autoregulation of the early promoter activity and in the release of the down-regulation of the late promoter by the GC motifs.
在病毒DNA复制之前测量的晚期启动子活性，源于增强子和21bp重复序列中负性和正性顺式作用元件的复杂相互作用。位于21bp重复序列内的GC基序，与重叠早期TATA盒的序列协同作用，下调晚期启动子活性。插入突变体分析表明，晚期启动子可能至少部分受到早期启动子机制的负调控。在T抗原存在的情况下，位于增强子内的GTI基序以及GC基序失去下调晚期启动子的能力。用tsA58蛋白获得的结果表明，T抗原的两个不同结构域参与早期启动子活性的负性自我调节，以及GC基序对晚期启动子下调作用的解除。
