Dynan W S, Sazer S, Tjian R, Schimke R T
Nature. 1986;319(6050):246-8. doi: 10.1038/319246a0.
Human (HeLa) cells contain a host-cell-encoded transcription factor, Sp1, which is required for transcription of simian virus 40 (SV40) promoters. Since the discovery of Sp1 we have been interested in learning what role this factor plays in uninfected cells. A monkey cellular gene promoter interacts with Sp1, but no gene products linked to this promoter have yet been identified. The finding that the sequence of the 5'-flanking DNA of the mouse dihydrofolate reductase (DHFR) gene contains several regions showing strong homology to the Sp1 binding region of simian virus 40 (SV40) prompted us to undertake experiments with dhfr. We report here that Sp1 binds to these regions in the dhfr promoter, and that Sp1-containing preparations stimulate transcription from the dhfr promoter in an in vitro reaction. Our results suggest that in addition to its interactions with the SV40 viral promoter, one function of Sp1 is to direct the expression of the cellular DHFR gene.
人（HeLa）细胞含有一种宿主细胞编码的转录因子Sp1，它是猿猴病毒40（SV40）启动子转录所必需的。自从发现Sp1以来，我们一直对了解该因子在未感染细胞中所起的作用感兴趣。一种猴细胞基因启动子与Sp1相互作用，但尚未鉴定出与此启动子相关的基因产物。小鼠二氢叶酸还原酶（DHFR）基因5'侧翼DNA序列包含几个与猿猴病毒40（SV40）的Sp1结合区域具有高度同源性的区域，这一发现促使我们对dhfr进行实验。我们在此报告，Sp1与dhfr启动子中的这些区域结合，并且含Sp1的制剂在体外反应中刺激dhfr启动子的转录。我们的结果表明，除了与SV40病毒启动子相互作用外，Sp1的一个功能是指导细胞DHFR基因的表达。
