High Quality Content by WIKIPEDIA articles! The nuclear receptor coactivator 1 (NCOA1) is a transcriptional coregulatory protein that contains several nuclear receptor interacting domains and an intrinsic histone acetyltransferase activity (EC 2.3.1.48). NCOA1 is recruited to DNA promotion sites by ligand-activated nuclear receptors. NCOA1, in turn, acylates histones, which makes downsteam DNA more accessible to transcription. Hence, NCOA1 assists nuclear receptors in the upregulation of DNA expression.