Acts both as coactivator and as corepressor. May play a role in chromatin remodeling. Activator of the Wnt signaling pathway in a DVL1-dependent manner by negatively regulating the GSK3B phosphotransferase activity. Induces dephosphorylation of GSK3B at 'Tyr-216'. Down-regulates TRIM24-mediated activation of transcriptional activation by AR. Transcriptional corepressor that down-regulates the expression of target genes. Binds to target promoters, leading to increased histone H3 acetylation at 'Lys-9' (H3K9ac). Binds to the ESR1 promoter. Recruits BRCA1 and POU2F1 to the ESR1 promoter. Coactivator for TP53-mediated activation of transcription of a set of target genes. Required for TP53-mediated cell-cycle arrest in response to oncogene activation. Promotes acetylation of TP53 at 'Lys-382', and thereby promotes efficient recruitment of TP53 to target promoters. Inhibits cell cycle progression from G1 to S phase (By similarity). Interacts with TRIM24, PTPN13 and DVL1. Identified in a complex with SMARCA4/BRG1, SMARCC1/BAF155, SMARCE1/BAF57, DPF2/BAF45D and ARID2, subunits of the SWI/SNF-B (PBAF) chromatin remodeling complex. Interacts with IRF2 and HNRPUL1. Interacts (via N-terminus) with TP53. Interacts (via C-terminus) with EP300. Interacts with BRCA1. Interacts (via bromo domain) with histone H3 (via N-terminus) acetylated at 'Lys-14' (H3K14ac). Has low affinity for histone H3 acetylated at 'Lys-9' (H3K9ac). Has the highest affinity for histone H3 that is acetylated both at 'Lys-9' (H3K9ac) and at 'Lys-14' (H3K14ac). Has very low affinity for non-acetylated histone H3. Interacts (via bromo domain) with histone H4 (via N-terminus) acetylated at 'Lys-8' (H3K8ac) (in vitro) (By similarity).