Scaffold subunit of various histone acetyltransferase (HAT) complexes, such as the MOZ/MORF and HBO1 complexes, which have a histone H3 acetyltransferase activity (PubMed:16387653, PubMed:24065767, PubMed:27939640). Plays a key role in HBO1 complex by directing KAT7/HBO1 specificity towards histone H3 'Lys-14' acetylation (H3K14ac) (PubMed:24065767). Some HAT complexes preferentially mediate histone H3 'Lys-23' (H3K23ac) acetylation (PubMed:27939640). Positively regulates the transcription of RUNX1 and RUNX2 (PubMed:18794358). Component of some HBO1 complex composed of KAT7/HBO1, MEAF6, ING5, and BRPF1 (PubMed:24065767). Component of the MOZ/MORF complex composed at least of ING5, KAT6A, KAT6B, MEAF6 and one of BRPF1, BRD1/BRPF2 and BRPF3 (PubMed:16387653, PubMed:18794358, PubMed:27939640). Interacts (via PHD-type zinc finger domains) with unmethylated histone H3 at 'Lys-4' (H3K4me0) (PubMed:24065767). Interacts with trimethylated 'Lys-36' of histone H3 (H3K36me3) (PubMed:20400950, PubMed:21720545). Interacts with ING5; interaction directs BRPF1 to H4K4me3-enriched chromatin at the 5' of active genes (PubMed:24065767). Interacts with KAT7 (PubMed:27939640). Localization to the nucleus depends on KAT6A, ING5 and MEAF6 (PubMed:18794358, PubMed:27939640). Localizes to transcription start sites (PubMed:24065767). High levels in testis. Acetylated by KAT6A. The disease is caused by variants affecting the gene represented in this entry.