WAPL maintains dynamic cohesin to preserve lineage specific distal gene regulation

The cohesin complex plays essential roles in sister chromatin cohesin, chromosome organization and gene expression. The role of cohesin in gene regulation is incompletely understood. Here, we report that the cohesin release factor WAPL is crucial for maintaining a pool of dynamic cohesin bound to regions that are associated with lineage specific genes in mouse embryonic stem cells. These regulatory regions are enriched for active enhancer marks and transcription factor binding sites, but largely devoid of CTCF binding sites. Stabilization of cohesin, which leads to a loss of dynamic cohesin from these regions, does not affect transcription factor binding or active enhancer marks, but does result in changes in promoter-enhancer interactions and downregulation of genes. Acute cohesin depletion can phenocopy the effect of WAPL depletion, showing that cohesin plays a crucial role in maintaining expression of lineage specific genes. The binding of dynamic cohesin to chromatin is dependent on the pluripotency transcription factor OCT4, but not NANOG. Finally, dynamic cohesin binding sites are also found in differentiated cells, suggesting that they represent a general regulatory principle. We propose that cohesin dynamically binding to regulatory sites creates a favorable spatial environment in which promoters and enhancers can communicate to ensure proper gene expression.