GCN5 (general control of amino-acid synthesis 5) is a 94 kD member of the N-acetyltransferase superfamily. This nuclear protein is highly expressed in the liver where it functions as a transcriptional co-activator, transfering acetyl group from acetyl-CoA to epsilon amino acid of lysine 14 in core histone H3 to control chromatin remodeling during transcriptional activation. GCN5 is a component of the human STAGA transactivator complex (SPT3, TAF, and GCN5) and can be modified by phosphorylation (which inhibits activity). In addition to the STAGA complex proteins, GCN5 has been shown to interact with E1A and Myc.