Nuclear receptor coactivator that directly binds nuclear receptors and stimulates the transcriptional activities in a hormone-dependent fashion. Plays a central role in creating a multisubunit coactivator complex, probably via remodeling of chromatin. Involved in the coactivation of different nuclear receptors, such as retinoids (RAR and RXR), thyroid hormone (TR) and orphan nuclear receptor (hepatocyte nuclear receptor 4 (HNF4) and constitutive androstane receptor (CAR)). Displays histone acetyltransferase activity. acetyl-CoA + L-lysyl-[protein] = CoA + H(+) + N(6)-acetyl-L-lysyl-[protein] Interacts with the histone acetyltransferase protein EP300. Mainly cytoplasmic and weakly nuclear. A number of isoforms may be produced. Highly expressed in liver and in early stages of oocyte development. Expressed only in early stages of oocyte development. Expression is more prominent in stage I, strongly decreases in stage II and then, gradually disappears. Contains three Leu-Xaa-Xaa-Leu-Leu (LXXLL) motifs. Motifs 1 and 2 are essential for the association with nuclear receptors, and constitute the RID domain (Receptor-interacting domain). Phosphorylated and acetylated. Belongs to the SRC/p160 nuclear receptor coactivator family.