Hubrecht Institute-KNAW and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands.
Hubrecht Institute-KNAW and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands.
Mol Cell. 2015 Nov 19;60(4):676-84. doi: 10.1016/j.molcel.2015.09.023. Epub 2015 Oct 29.
CCCTC-binding factor (CTCF) is an architectural protein involved in the three-dimensional (3D) organization of chromatin. In this study, we assayed the 3D genomic contact profiles of a large number of CTCF binding sites with high-resolution 4C-seq. As recently reported, our data also suggest that chromatin loops preferentially form between CTCF binding sites oriented in a convergent manner. To directly test this, we used CRISPR/Cas9 genome editing to delete core CTCF binding sites in three loci, including the CTCF site in the Sox2 super-enhancer. In all instances, CTCF and cohesin recruitment were lost, and chromatin loops with distal, convergent CTCF sites were disrupted or destabilized. Re-insertion of oppositely oriented CTCF recognition sequences restored CTCF and cohesin recruitment, but did not re-establish chromatin loops. We conclude that CTCF binding polarity plays a functional role in the formation of higher-order chromatin structure.
CCCTC 结合因子（CTCF）是一种参与染色质三维（3D）组织的结构蛋白。在这项研究中，我们使用高分辨率 4C-seq 检测了大量 CTCF 结合位点的 3D 基因组接触谱。最近的报道表明，我们的数据还表明，染色质环优先在定向会聚的 CTCF 结合位点之间形成。为了直接验证这一点，我们使用 CRISPR/Cas9 基因组编辑删除了三个基因座中的核心 CTCF 结合位点，包括 Sox2 超级增强子中的 CTCF 位点。在所有情况下，CTCF 和 cohesin 的募集都丢失了，并且具有远端、会聚 CTCF 位点的染色质环被破坏或失稳。相反定向的 CTCF 识别序列的重新插入恢复了 CTCF 和 cohesin 的募集，但没有重新建立染色质环。我们得出结论，CTCF 结合极性在高级染色质结构的形成中起着功能作用。
