DNA helicase that acts as a chromatin remodeling factor and regulates transcription. Acts as a transcription repressor by remodeling chromatin structure and recruiting histone H1 to target genes. Suppresses p53/TP53-mediated apoptosis by recruiting histone H1 and preventing p53/TP53 transactivation activity. Acts as a negative regulator of Wnt signaling pathway by regulating beta-catenin (CTNNB1) activity. Negatively regulates CTNNB1-targeted gene expression by being recruited specifically to the promoter regions of several CTNNB1 responsive genes. Involved in both enhancer blocking and epigenetic remodeling at chromatin boundary via its interaction with CTCF. Acts as a suppressor of STAT3 activity by suppressing the LIF-induced STAT3 transcriptional activity. Also acts as a transcription activator via its interaction with ZNF143 by participating in efficient U6 RNA polymerase III transcription. ATP + H2O = ADP + H(+) + phosphate Interacts with CTNNB1 and PIAS3. Component of some MLL1/MLL complex, at least composed of the core components KMT2A/MLL1, ASH2L, HCFC1/HCF1, WDR5 and RBBP5, as well as the facultative components BAP18, CHD8, E2F6, HSP70, INO80C, KANSL1, LAS1L, MAX, MCRS1, MGA, KAT8/MOF, PELP1, PHF20, PRP31, RING2, RUVB1/TIP49A, RUVB2/TIP49B, SENP3, TAF1, TAF4, TAF6, TAF7, TAF9 and TEX10. Interacts with CHD7. Interacts with FAM124B (By similarity). Interacts with p53/TP53 and histone H1 (PubMed:19151705). Interacts with CTCF (PubMed:16949368). Localizes to the promoter regions of several CTNNB1-responsive genes. Also present at known CTCF target sites. Expressed predominantly from early- to mid-stage mouse embryogenesis. Detected throughout embryos from 7.5 to 9.5 dpc but localizes predominantly in the brain, faces, branchial arches, limb buds, and tail buds of embryos at 10.5 dpc. Sumoylated. Death during early embryogenesis due to widespread apoptosis. Embryos manifest growth retardation from 5.5 dpc and developmental arrest accompanied by massive apoptosis at 7.5 dpc. They develop into an egg cylinder but do not form a primitive streak or mesoderm. Mice lacking both Tp53 and Chd8 ameliorate this developmental arrest. Belongs to the SNF2/RAD54 helicase family. CHD8 subfamily. Partially unspliced pre-RNA.