CBP a protein acetyltransferase that can transcriptionally activate histones. Acetylates the NCOA3 coactivator. Binds specifically to phosphorylated CREB1 and enhances its transcriptional activity toward cAMP-responsive genes. Methylation of the KIX domain by CARM1 blocks association with CREB, blocking CREB signaling, and activating the apoptotic response. Found in a complex containing NCOA2, NCOA3, IKKA, IKKB, and IKBKG. Probably part of a complex with HIF1A and EP300. Interacts with the C-terminal region of CITED4. The TAZ-type 1 domain interacts with HIF1A. Interacts with MAF, SRCAP, CARM1, ELF3, MLLT7/FOXO4, N4BP2, NCOA1, NCOA3, NCOA6, PCAF, PELP1, PML, SMAD1, SMAD2, SMAD3, SPIB and TRERF1. Interacts with HTLV-1 Tax, p30II, and HIV-1 Tat. Interacts with KLF1;