Proudfoot N J, Lee B A, Monks J
Sir William Dunn School of Pathology, University of Oxford, United Kingdom.
New Biol. 1992 Apr;4(4):369-81.
We demonstrate that multiple SP1 protein:DNA binding sites confer enhancer-independent activation on the HIV-1 and globin gene promoters. This activation process can be achieved either by DNA replication of the promoter-containing plasmid or by high concentrations of input plasmid DNA used in the transfections. In the case of HIV-1, the three SP1 sites adjacent to the promoters TATA box are essential for this activation process. Furthermore, the human beta globin gene, which is normally dependent on a linked enhancer for transcriptional activity, can be made enhancer independent by insertion of SP1 binding sites adjacent to its TATA box. We speculate that (SP1)n-TATA type RNA polymerase II promoters may be generally permissive when present on actively replicating DNA templates and that this property of the HIV-1 promoter may be of importance to the activation of the DNA provirus in latently infected T cells.
我们证明多个SP1蛋白与DNA的结合位点可赋予HIV-1和珠蛋白基因启动子不依赖增强子的激活作用。这种激活过程可以通过含启动子质粒的DNA复制或转染中使用的高浓度输入质粒DNA来实现。对于HIV-1，启动子TATA框附近的三个SP1位点对于该激活过程至关重要。此外，通常依赖于相连增强子进行转录活性的人β珠蛋白基因，可通过在其TATA框附近插入SP1结合位点而变得不依赖增强子。我们推测，当存在于活跃复制的DNA模板上时，(SP1)n-TATA型RNA聚合酶II启动子可能普遍具有易感性，并且HIV-1启动子的这一特性可能对潜伏感染的T细胞中DNA原病毒的激活具有重要意义。
