MULTIPLE DNA ELEMENTS ARE REQUIRED FOR THE GROWTH-REGULATION OF THE MOUSE E2F1 PROMOTER
MULTIPLE DNA ELEMENTS ARE REQUIRED FOR THE GROWTH-REGULATION OF THE MOUSE E2F1 PROMOTER
复制标题
DOI：
10.1101/gad.8.13.1526
复制
发表时间：
1994-07-01
影响因子：
10.5
通讯作者：
FARNHAM, PJ
中科院分区：
文献类型：
--
作者：
HSIAO, KM;MCMAHON, SL;FARNHAM, PJ
为了准备细胞周期的DNA合成（S）期，核苷酸生物合成所需的许多基因的转录增加。这些基因中的几个的启动子含有E2 F家族转录因子的结合位点，并且在许多情况下，这些位点的突变废除了生长调节的转录。其中一个家族成员E2 F1的RNA水平在G（1）/S期边界增加约15倍，并且E2 F1在静止细胞中的表达激活了一些G（1）/S期特异性启动子的转录，表明E2 F1在准备细胞进入S期中起关键作用。为了阐明导致DNA合成所需基因激活的信号转导途径，我们正在研究E2 F1表达调控的机制。为了确定E2 F1 mRNA水平是否受启动子活性变化的控制，我们克隆了小鼠E2 F1启动子并进行了表征。序列分析显示，两组重叠的E2 F结合位点位于相对于转录起始位点的-12和-40之间。我们表明，这些网站结合细胞E2 F和E2 F1启动子片段可以激活高达100倍的E2 F蛋白的共表达。我们还表明，E2 F1启动子片段的活性在G（1）/S-期边界增加了80倍，并且这种激活部分受到G（0）特异性阻遏通过E2 F位点的调节。然而，E2 F位点不足以介导生长调节的转录活性;我们的结果表明，在G（1）/S期边界的E2 F1启动子的转录调节需要多个DNA元件。
To prepare for the DNA synthesis (S) phase of the cell cycle, transcription of many genes required for nucleotide biosynthesis increases. The promoters of several of these genes contain binding sites for the E2F family of transcription factors, and, in many cases, mutation of these sites abolishes growth-regulated transcription. The RNA levels of one family member, E2F1, increase about 15-fold at the G(1)/S-phase boundary and expression of E2F1 in quiescent cells activates transcription from some G(1)/S-phase-specific promoters, suggesting that E2F1 plays a critical role in preparing cells to enter S phase. To elucidate the signal transduction pathway leading to the activation of genes required for DNA synthesis, we are investigating the mechanism by which expression of E2F1 is regulated. To determine whether levels of E2F1 mRNA are controlled by changes in promoter activity, we have cloned and characterized the mouse E2F1 promoter. Sequence analysis revealed two sets of overlapping E2F-binding sites located between -12 and -40 relative to the transcription initiation site. We show that these sites bind cellular E2F and that an E2F1 promoter fragment can be activated up to 100-fold by coexpression of E2F proteins. We also show that the activity of this E2F1 promoter fragment increases similar to 80-fold at the G(1)/S-phase boundary and that this activation is, in part, regulated by G(0)-specific repression via the E2F sites. However, the E2F sites are not sufficient to mediate growth-regulated transcriptional activity; our results indicate that multiple DNA elements are required for transcription regulation of the E2F1 promoter at the G(1)/S-phase boundary.