Diversity of core promoter elements comprising human bidirectional promoters.
Diversity of core promoter elements comprising human bidirectional promoters.
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DOI：
10.1186/1471-2164-9-s2-s3
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发表时间：
2008-09-16
期刊：
影响因子：
4.4
通讯作者：
Elnitski LL
中科院分区：
文献类型：
--
作者：
Yang MQ;Elnitski LL
双向启动子位于相邻基因之间，由相反的 DNA 链转录。双向启动子激活的功能机制目前尚不清楚。为了定义人类双向启动子的核心启动子元件，我们绘制了 TATA、INR、BRE、DPE、INR 以及 CpG 岛的基序。我们发现 C+G 含量、CpG 岛存在和平均表达水平之间始终存在高度对应关系，增加了双向启动子中所有基因的中位水平。这些富含 CpG 的启动子表现出离散的起始模式，而不是像 CpG 岛启动子通常看到的广泛的转录起始区域。 CpG 岛包含双向启动子内的两个 TSS，为许多这些基因的对称共表达模式提供了解释。相比之下，TATA 基序似乎不对称地定位在一个 TSS 或另一个 TSS 上。我们的研究结果表明，双向启动子利用多种核心启动子元件来启动转录。 CpG 岛在这组启动子的监管环境中占主导地位。
Bidirectional promoters lie between adjacent genes, which are transcribed from opposite strands of DNA. The functional mechanisms underlying the activation of bidirectional promoters are currently uncharacterised. To define the core promoter elements of bidirectional promoters in human, we mapped motifs for TATA, INR, BRE, DPE, INR, as well as CpG-islands. We found a consistently high correspondence between C+G content, CpG-island presence and an average expression level increasing the median level for all genes in bidirectional promoters. These CpG-rich promoters showed discrete initiation patterns rather than broad regions of transcription initiation, as are typically seen for CpG-island promoters. CpG-islands encompass both TSSs within bidirectional promoters, providing an explanation for the symmetrical co-expression patterns of many of these genes. In contrast, TATA motifs appear to be asymmetrically positioned at one TSS or the other. Our findings demonstrate that bidirectional promoters utilize a variety of core promoter elements to initiate transcription. CpG-islands dominate the regulatory landscape of this group of promoters.