CTCF Binding Polarity Determines Chromatin Looping
2015; Elsevier BV; Volume: 60; Issue: 4 Linguagem: Inglês
10.1016/j.molcel.2015.09.023
ISSN1097-4164
AutoresElzo de Wit, Erica S.M. Vos, Sjoerd J.B. Holwerda, Christian Valdes‐Quezada, Marjon J.A.M. Verstegen, Hans Teunissen, Erik Splinter, Patrick J. Wijchers, Peter H.L. Krijger, Wouter de Laat,
Tópico(s)Chromosomal and Genetic Variations
ResumoCCCTC-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.
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