Synonyms:AIB3, KIAA0181, RAP250, TRBP Background:Nuclear receptor coactivator that directly binds nuclear receptors and stimulates the transcriptional activities in a hormone-dependent fashion. Coactivates expression in an agonist-and AF2-dependent manner. Involved in the coactivation of different nuclear receptors, such as for steroids(GR and ERs), retinoids(RARs and RXRs), thyroid hormone(TRs), vitamin D3(VDR) and prostanoids(PPARs). Probably functions as a general coactivator, rather than just a nuclear receptor coactivator. May also be involved in the coactivation of the NF-kappa-B pathway. May coactivate expression via a remodeling of chromatin and its interaction with histone acetyltransferase proteins.