Regulation of SV40 large T-antigen stability by reversible acetylation

• DOI: 10.1038/sj.onc.1209731
• Publication Date: 2006-06-12T12:15:26Z
• Authors: T Shimazu; Y Komatsu; K I Nakayama; H Fukazawa; S Horinouchi; M Yoshida
• Keywords: Spectrometry, Mass, Electrospray Ionization; 0303 health sciences; Base Sequence; Antigens, Polyomavirus Transforming; Molecular Sequence Data; Acetylation; Histone Deacetylases; Mice; 03 medical and health sciences; Sirtuin 1; COS Cells; Chlorocebus aethiops; Animals; Sirtuins; Amino Acid Sequence; Chromatography, High Pressure Liquid; DNA Primers

Reversible acetylation on protein lysine residues has been shown to regulate the function of both nuclear proteins such as histones and p53 and cytoplasmic proteins such as alpha-tubulin. To identify novel acetylated proteins, we purified several proteins by the affinity to an anti-acetylated-lysine antibody from cells treated with trichostatin A (TSA). Among the proteins identified, here we report acetylation of the SV40 large T antigen (T-Ag). The acetylation site was determined to be lysine-697, which is located adjacent to the C-terminal Cdc4 phospho-degron (CPD). Overexpression of the CBP acetyltransferase acetylated T-Ag, whereas HDAC1, HDAC3 and SIRT1 bound and deacetylated T-Ag. The acetylation and deacetylation occurred independently of p53, a binding partner of T-Ag, but the acetylation was enhanced in the presence of p53. T-Ag in the cells treated with TSA and NA or the acetylation mimic mutant (K697Q) became unstable in COS-7 cells, suggesting that acetylation regulates stability of T-Ag. Indeed, NIH3T3 cells stably expressing K697Q showed decreased anchorage-independent growth compared with those expressing wild type or the K697R mutant. These results demonstrate that acetylation destabilizes T-Ag and regulates the transforming activity of T-Ag in NIH3T3 cells.