Mutant p53 forms a complex with Sp1 on HIV-LTR DNA
Mutant p53 forms a complex with Sp1 on HIV-LTR DNA
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DOI：
10.1006/bbrc.2000.3965
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发表时间：
2000-12-20
影响因子：
3.1
通讯作者：
Bargonetti, J
中科院分区：
文献类型：
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作者：
Chicas, A;Molina, P;Bargonetti, J
p53的许多突变体激活HIV-LTR驱动的转录并促进HIV复制。HIV-LTR中含有Sp1结合位点的区域对这种效应很重要。在这项研究中，我们测试的假设，突变p53与DNA结合的Sp1相互作用，并以这种方式可以增加转录Sp1依赖性启动子。我们使用表达内源性突变型p53（His 273）的乳腺癌细胞系MDA-MB-468作为我们的p53蛋白来源。首先，我们通过显示MDA-MB-468细胞中HIV-LTR指导的转录被p53（Val 135）以显性负性方式抑制，证明该突变体p53参与激活HIV-LTR的转录。用HIV-LTR DNA亲和层析，我检测到p53（His 273）和Sp1的共洗脱。我们还证明，这种突变的p53结合序列特异性的超共有序列（SCS）和Sp1共洗脱与p53（His 273）从含有该网站的列。这些数据表明，p53（His 273）可以与DNA结合的Sp1，这表明与突变型p53相关的激活的HIV-LTR转录通过DNA驱动的多蛋白复合物发生。(C)北京大学出版社.
Many mutants of p53 activate HIV-LTR driven transcription and promote HIV replication. The region of the HIV-LTR containing Sp1-binding sites is important for this effect. In this study we test the hypothesis that mutant p53 interacts with DNA-bound Sp1 and in this way can increase transcription from Sp1-dependent promoters. We have used the breast cancer cell line MDA-MB-468 that expresses endogenous mutant p53(His273) as our source of p53 protein. First, we demonstrated that this mutant p53 participates in activating transcription from the HIV-LTR by showing that HIV-LTR-directed transcription in MDA-MB-468 cells is inhibited in a dominant-negative manner by p53(Val135). Using HIV-LTR DNA affinity chromatography, me detected coelution of p53(His273) and Sp1. We also demonstrated that this mutant p53 binds sequence specifically to the super consensus sequence (SCS) and that Sp1 coeluted with p53(His273) from a column containing this site. These data indicate that p53(His273) can associate with DNA-bound Sp1 suggesting that activated HIV-LTR transcription associated with mutant p53 occurs through a DNA driven multi-protein complex. (C) 2000 Academic Press.