Bromodomain-containing protein 8 is a protein that in humans is encoded by the BRD8 gene. The protein encoded by this gene interacts with thyroid hormone receptor in a ligand-dependent manner and enhances thyroid hormone-dependent activation from thyroid response elements. This protein contains a bromodomain and is thought to be a nuclear receptor coactivator. BRD8 may act as a coactivator during transcriptional activation by hormone-activated nuclear receptors. Three alternatively spliced transcript variants that encode distinct isoforms have been identified. Isoform 2 stimulates transcriptional activation by AR/DHTR, ESR1/NR3A1, RXRA/NR2B1 and THRB/ERBA2. At least isoform 1 and isoform 2 are components of the NuA4 histone acetyltransferase (HAT) complex which is involved in transcriptional activation of select genes principally by acetylation of nucleosomal histone H4 and H2A. This modification may both alter nucleosome - DNA interactions and promote interaction of the modified histones with other proteins which positively regulate transcription. This complex may be required for the activation of transcriptional programs associated with oncogene and proto-oncogene mediated growth induction, tumor suppressor mediated growth arrest and replicative senescence, apoptosis, and DNA repair. NuA4 may also play a direct role in DNA repair when recruited to sites of DNA damage. It interacts with MYC and adenovirus E1A protein.