By sequence similarity p300 is related to CBP (CREB-binding protein) and functions as a histone acetyltransferase that can regulate transcription by influencing chromatin organization. P300 has been demonstrated to bind to phosphorylated CREB to mediate cAMP-gene regulation. P300 has also been identified as a co-activator of HIF1A (hypoxia-inducible factor 1 alpha).
