Hubrecht Institute-KNAW and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
Philos Trans R Soc Lond B Biol Sci. 2013 May 6;368(1620):20120369. doi: 10.1098/rstb.2012.0369. Print 2013.
CTCF has it all. The transcription factor binds to tens of thousands of genomic sites, some tissue-specific, others ultra-conserved. It can act as a transcriptional activator, repressor and insulator, and it can pause transcription. CTCF binds at chromatin domain boundaries, at enhancers and gene promoters, and inside gene bodies. It can attract many other transcription factors to chromatin, including tissue-specific transcriptional activators, repressors, cohesin and RNA polymerase II, and it forms chromatin loops. Yet, or perhaps therefore, CTCF's exact function at a given genomic site is unpredictable. It appears to be determined by the associated transcription factors, by the location of the binding site relative to the transcriptional start site of a gene, and by the site's engagement in chromatin loops with other CTCF-binding sites, enhancers or gene promoters. Here, we will discuss genome-wide features of CTCF binding events, as well as locus-specific functions of this remarkable transcription factor.
CTCF 无所不能。这种转录因子可以与数万个基因组位点结合，有些是组织特异性的，有些则是超保守的。它可以作为转录激活剂、抑制剂和绝缘子，也可以暂停转录。CTCF 结合在染色质域边界、增强子和基因启动子内，以及基因体内。它可以吸引许多其他转录因子到染色质上，包括组织特异性转录激活因子、抑制剂、黏合蛋白和 RNA 聚合酶 II，并且它可以形成染色质环。然而，或者正是因为如此，CTCF 在特定基因组位点的精确功能是不可预测的。它似乎取决于相关的转录因子，取决于结合位点相对于基因转录起始位点的位置，以及该位点与其他 CTCF 结合位点、增强子或基因启动子形成染色质环的情况。在这里，我们将讨论 CTCF 结合事件的全基因组特征，以及这个非凡转录因子的特定基因座功能。
