CTCF and Insulator interact with Xist during spreading associated with epigenetic gene regulation.

We demonstrate here that chromatin compaction and local compaction status of the DNA are controlled by Xist. During unwinding of the DNA induced following activation or repression of the non-coding RNA Xist in somatic cells, an event that involves recruitment of a separate Xist species containing the Xist RNP functioning in local gene regulation, we provide evidence for an active function of CTCF at the genomic site of repair or transcription that marks occupancy and active site boundaries and facilitates local control guided by control of spreading by CTCF and Insulator. CTCF depletion disrupted Xist localization factors including Ciz1 and induced switching in choice of nucleosome chromatin assembly modification factors functioning in spreading, including Nap1l1 and Nap1l4, Smarcc1 and Smarcc2 and Atad3a.