Ciavatta Dominic, Rogers Steve, Magnuson Terry
Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
J Mol Biol. 2007 Oct 19;373(2):233-9. doi: 10.1016/j.jmb.2007.07.065. Epub 2007 Aug 14.
CTCF is a conserved transcriptional regulator with binding sites in DNA insulators identified in vertebrates and invertebrates. The Drosophila Abdominal-B locus contains CTCF binding sites in the Fab-8 DNA insulator. Previous reports have shown that Fab-8 has enhancer blocking activity in Drosophila transgenic assays. We now confirm the enhancer blocking capability of the Fab-8 insulator in stably transfected Drosophila S2 cells and show this activity depends on the Fab-8 CTCF binding sites. Furthermore, knockdown of Drosophila CTCF by RNAi in our stable cell lines demonstrates that CTCF itself is critical for Fab-8 enhancer blocking.
CTCF是一种保守的转录调节因子，在脊椎动物和无脊椎动物的DNA绝缘子中具有结合位点。果蝇的腹部B基因座在Fab-8 DNA绝缘子中含有CTCF结合位点。先前的报道表明，Fab-8在果蝇转基因试验中具有增强子阻断活性。我们现在证实了Fab-8绝缘子在稳定转染的果蝇S2细胞中的增强子阻断能力，并表明这种活性依赖于Fab-8 CTCF结合位点。此外，在我们的稳定细胞系中通过RNAi敲低果蝇CTCF表明，CTCF本身对于Fab-8增强子阻断至关重要。
