Protein Science Key Laboratory of the Ministry of Education, Department of Pharmacology, School of Medicine, Tsinghua University, Beijing 100084, China.
Gene. 2013 Nov 15;531(1):64-70. doi: 10.1016/j.gene.2013.07.054. Epub 2013 Aug 9.
A majority of mammalian promoters are associated with CpG islands. CpG island promoters frequently lack common core promoter elements, such as the TATA box, and often have dispersed transcription start sites. The mechanism through which CpG island promoters are transcriptionally initiated remains unclear. We speculate that some transcription factors can direct transcription initiation by themselves. To test this hypothesis, we screened a variety of transcription factors to see whether they could initiate transcription. Most transcription factors, including specificity protein 1 (Sp1) and nuclear factor Y (NF-Y), showed little transcriptional initiation activity. However, nuclear respiratory factor 1 (NRF-1), the basic helix-loop-helix/leucine zipper (bHLH/ZIP) family of proteins and the E-twenty six (Ets) family of proteins had strong transcriptional activity. We further demonstrated that these transcription factors initiate dispersed transcription. Our studies provide perspectives to the mechanism of transcription initiation from CpG island promoters.
大多数哺乳动物启动子与 CpG 岛相关。CpG 岛启动子通常缺乏常见的核心启动子元件，如 TATA 盒，并且通常具有分散的转录起始位点。CpG 岛启动子转录起始的机制尚不清楚。我们推测，一些转录因子可以自行指导转录起始。为了验证这一假设，我们筛选了多种转录因子，以观察它们是否能够起始转录。大多数转录因子，包括特异性蛋白 1（Sp1）和核因子 Y（NF-Y），显示出很少的转录起始活性。然而，核呼吸因子 1（NRF-1）、碱性螺旋-环-螺旋/亮氨酸拉链（bHLH/ZIP）家族蛋白和 E 二十六（Ets）家族蛋白具有很强的转录活性。我们进一步证明这些转录因子起始分散的转录。我们的研究为 CpG 岛启动子转录起始的机制提供了新的视角。
