| Here , we show that the SNF 2 like chromodomain helicase protein CHD 8 interacts with the insulator binding protein CTCF . ^^^ Chromatin immunoprecipitation analysis revealed that CHD 8 was present at known CTCF target sites , such as the differentially methylated region ( DMR ) of H 19 , the locus control region of beta globin , and the promoter region of BRCA 1 and c myc genes . ^^^ RNA interference mediated knockdown of CHD 8 significantly abolished the H 19 DMR insulator activity that depends highly on CTCF , leading to reactivation of imprinted IGF 2 from chromosome of maternal origin . ^^^ Further , the lack of CHD 8 affected CpG methylation and histone acetylation around the CTCF binding sites , adjacent to heterochromatin , of BRCA 1 and c myc genes . ^^^ These findings provide insight into the role of CTCF CHD 8 complex in insulation and epigenetic regulation at active insulator sites . . ^^^ |