GCN5L2 (C26A10) Rabbit mAb #3305

General Control of Amino Acid Synthesis Yeast Homolog Like 2 (GCN5L2) is a transcription adaptor protein and a histone acetyltransferase (HAT) that functions as the catalytic subunit of the STAGA and TFTC transcription coactivator complexes (1). GCN5L2 is 73% homologous to the p300/CBP-associated factor PCAF, another HAT protein found in similar complexes (2). Free GCN5L2 acetylates histone H3 on Lys14; however, when part of coactivator complexes, GCN5L2 acetylates histone H3 at Lys9, 14, 18, and 23, and to a smaller extent histones H4 and H2B (3). Histone acetylation contributes to gene activation by modulating chromatin structure and recruiting additional coactivator proteins that contain acetyl-lysine binding bromodomains (4). GCN5L2 also acetylates non-histone proteins such as transcription activators (TAT, c-Myb) (5,6), transcription co-activators (PGC1-α) (7), and nuclear receptors (Steroidogenic Factor 1) (8). Acetylation of these proteins regulates their nuclear localization, protein stability, DNA binding, and co-activator association (5-8). GCN5L2 is recruited to gene promoters during transactivation through interactions with multiple transcription activator proteins such as Myc, E2F, p53, and BRCA1 (9-12). The STAGA and TFTC complexes also interact with SAP130 and DDB1, two structurally related proteins involved in RNA splicing and DNA repair, suggesting roles for GCN5L2 in processes other than transcription activation (13).