The DMAP1 gene encodes a protein that regulates the repression and activation of transcription by forming several distinct complexes. It forms a subunit of the NuA4 histone acetyltransferase (HAT) complex, which is responsible for carrying out the acetylation of the nucleosomal histones H2A and H4. This modification helps activate the transcription of certain genes, presumably by altering nucleosome-DNA interactions and promoting the association of the modified histones with other transcription-regulating proteins. DMAP1 also forms a repressive transcription complex with DNA methyltransferase 1 (DNMT1) and histone deacetylase 1 (HDAC1). Further, it interacts with DAXX to repress glucocorticoid-receptor mediated transcription. DMAP1 can also function independently to repress transcription.   

The DMAP1 gene, located on the short arm of chromosome 1, spans a length of just 7.2 kb of DNA. Its coding sequence is contained within 12 exons and it encodes a 52.9 kDa protein product comprised of 467 amino acids. Alternatively spliced transcript variants encoding the same protein have been identified. While DMAP1 is widely expressed, overexpression of the gene is seen in peripheral blood mononuclear cells and CD8 T-cells.