Offord E A, Beard P
Department of Virology, Swiss Institute for Experimental Cancer Research, Epalinges.
J Virol. 1990 Oct;64(10):4792-8. doi: 10.1128/JVI.64.10.4792-4798.1990.
Papillomaviruses are tissue specific and replicate in differentiating keratinocytes. We are interested in the question of tissue specificity at the level of transcription. We used extracts from human keratinocytes and human fibroblasts at low passage number and from HeLa cells to look for factors binding to the E6 promoter of human papillomavirus type 18 (HPV-18) DNA by footprint and gel mobility shift experiments. We found a factor present in HeLa and keratinocyte extracts but not in fibroblast extracts which bound about 160 base pairs upstream from the start of E6. The binding site included the sequence TGACTAAG, which resembles the consensus binding site for the AP-1 family of proteins. Synthetic oligonucleotides containing this binding site specifically competed with factor binding to HPV-18 DNA, as did the AP-1 sequence of simian virus 40. They also inhibited transcription from the E6 promoter in vitro in extracts from HeLa cells. Thus, the presence of this keratinocyte-specific factor seems to be important for HPV-18 transcription.
乳头瘤病毒具有组织特异性，在分化的角质形成细胞中复制。我们对转录水平上的组织特异性问题感兴趣。我们使用低传代次数的人角质形成细胞和人成纤维细胞提取物以及HeLa细胞提取物，通过足迹法和凝胶迁移率变动实验寻找与18型人乳头瘤病毒（HPV - 18）DNA的E6启动子结合的因子。我们发现HeLa细胞和角质形成细胞提取物中存在一种因子，而成纤维细胞提取物中不存在，该因子与E6起始点上游约160个碱基对结合。结合位点包括序列TGACTAAG，它类似于AP - 1蛋白家族的共有结合位点。含有该结合位点的合成寡核苷酸与因子结合HPV - 18 DNA特异性竞争，猿猴病毒40的AP - 1序列也是如此。它们还在体外抑制HeLa细胞提取物中E6启动子的转录。因此，这种角质形成细胞特异性因子的存在似乎对HPV - 18转录很重要。
