Multiple transcription factor binding sites mediate adenovirus E1A transactivation.
Multiple transcription factor binding sites mediate adenovirus E1A transactivation.
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多个转录因子结合位点介导腺病毒 E1A 反式激活。
DOI：
10.1128/jvi.63.8.3499-3506.1989
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发表时间：
1989
影响因子：
5.4
通讯作者：
Berk,AJ
中科院分区：
文献类型：
--
作者：
Pei,R;Berk,AJ
我们研究了简单的合成启动子区域对腺病毒早期区域1A(E1A)蛋白反式激活的反应。重组病毒突变株中的E1B启动子区域被一个或两个宿主细胞转录因子的结合位点取代，并在感染早期检测了对E1a反式激活的应答。我们发现，一个单一的CREB/ATF结合位点导致了一个令人惊讶的强大启动子，该启动子对E1a做出了反应。位于E1B TATA盒上游的CREB/ATF结合位点的作用与野生型E1B启动子非常相似，它由一个Sp1结合位点和一个TATA盒组成。一个单一的E2F结合位点导致了一个极弱的启动子，该启动子与E1a没有反应，很像一个单一的Sp1位点。与2型腺病毒E2早期启动子具有相同间距的两个E2F位点反向定位，产生了一个强大的E1a反应启动子。用E4TATA盒区域替代E1B TATA盒区域产生的启动子比野生型E1B启动子在没有E1A的情况下强约5倍。然而，E4 TATA盒替换对E1a反式激活没有显著的反应。这些结果直接证明了许多不同的转录因子结合位点，包括E1B TATA盒、CREB/ATF结合位点和两个E2F结合位点，都可以介导E1a的反式激活。其他转录因子结合位点不能介导E1a反应；这些其他位点包括E4TATA盒、单一的Sp1结合位点和单一的E2F结合位点。讨论了这些发现对E1a反式激活机制的影响。
We studied the response of simple synthetic promoter regions to transactivation by the adenovirus early region 1A (E1A) protein. Binding sites for one or two host cell transcription factors were substituted for the E1B promoter region in reconstructed virus mutants, and the response to E1A transactivation was assayed during the early phase of infection. We found that a single CREB/ATF binding site resulted in a surprisingly strong promoter which responded to E1A. A CREB/ATF binding site placed upstream of the E1B TATA box behaved much like the wild-type E1B promoter, which is composed of a single Sp1 binding site plus a TATA box. A single E2F binding site resulted in an extremely weak promoter which did not respond to E1A, much like a single Sp1 site. Two E2F sites in an inverted orientation with the same spacing as in the adenovirus type 2 E2 early promoter produced a strong, E1A-responsive promoter. Substitution of the E4 TATA box region for the E1B TATA box region produced a promoter about five times stronger than the wild-type E1B promoter in the absence of E1A. However, the E4 TATA box substitution did not respond significantly to E1A transactivation. These results directly demonstrate that many different transcription factor binding sites, including the E1B TATA box, a CREB/ATF binding site, and two E2F sites, can mediate E1A transactivation. Other transcription factor binding sites cannot mediate an E1A response; these other sites include the E4 TATA box, a single Sp1 binding site, and a single E2F binding site. Implications of these findings for the mechanism of E1A transactivation are discussed.