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.