Nuclear Factor of Activated T Cells (NFAT)-dependent Transactivation Regulated by the Coactivators p300/CREB-binding Protein (CBP)

p300 and cAMP response element–binding protein (CREB)–binding protein (CBP) are members of a family of coactivators involved in the regulation of transcription and chromatin. We show that transcription factors of the nuclear factor of activated T cells (NFAT) family bind p300/CBP and recruit histone acetyltransferase activity from T cell nuclear extracts. The NH₂-terminal transactivation domain of NFAT1 and the phospho-CREB- and E1A-binding sites of p300/CBP are involved in the interaction. The viral oncoprotein E1A inhibits NFAT-dependent transactivation in a p300-dependent manner. Recruitment of the coactivators p300/CBP by the transactivation domains of NFAT proteins is likely to play a critical role in NFAT-dependent gene expression during the immune response.