Nuclear receptor coactivator that directly binds nuclear receptors and stimulates the transcriptional activities in a hormone-dependent fashion. Coactivate expression in an agonist- and AF2-dependent manner. May coactivate expression via a remodeling of chromatin and its interaction with histone acetyltransferase proteins. 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 (By similarity). Monomer and homodimer. Interacts in vitro with the basal transcription factors GTF2A and TBP, suggesting an autonomous transactivation function. Interacts with NCOA1, CRSP3, RBM14, the histone acetyltransferase proteins EP300 and CREBBP, and with methyltransferase proteins NCOA6IP and PRMT2 (By similarity). Component of the MLL2/3 complex (also named ASCOM complex), at least composed of KMT2D/MLL2 or KMT2C/MLL3, ASH2L, RBBP5, WDR5, NCOA6, DPY30, KDM6A, PAXIP1/PTIP, PAGR1 and alpha- and beta-tubulin (By similarity). Interacts with ZNF335; may enhance ligand-dependent transcriptional activation by nuclear hormone receptors (By similarity). Contains one Leu-Xaa-Xaa-Leu-Leu (LXXLL) motif, which is essential for the association with nuclear receptors. Phosphorylated.