Fig. 8
From: The cohesin-associated protein Wapal is required for proper Polycomb-mediated gene silencing
Two models to explain the role of Wapal and cohesin in regulating PRC2 targeting. a A CTCF-occupied distal CRE is responsible for recruiting PRC2 to mediate gene silencing. The recruitment is through a direct CTCF:Suz12 interaction [22]. In this model, the CTCF site would function as a mammalian PRE. b Polycomb complexes target all sites of transcription, and need to be “evicted” from the TSS by a transcriptional enhancer. CTCF prevents this by “blocking” enhancer access to gene. Cohesin facilitates the required DNA loop to stabilize the CTCF/gene chromatin interaction