Mechanisms of P/CAF auto-acetylation

P/CAF is a histone acetyltransferase enzyme which was originally identified as a CBP/p300‐binding protein. In this manuscript we report that human P/CAF is acetylated in vivo. We find that P/CAF is acetylated by itself and by p300 but not by CBP. P/CAF acetylation can be an intra‐ or intermolecular event. The intermolecular acetylation requires the N‐terminal domain of P/CAF. The intramolecular acetylation targets five lysines (416–442) at the P/CAF C‐terminus, which are in the nuclear localisation signal (NLS). Finally, we show that acetylation of P/CAF leads to an increment of its histone acetyltransferase (HAT) activity. These findings identify a new post‐translation modification on P/CAF which may regulate its function.