Figure 1.

Schematic proposal of p53 regulation by sumoylation and acetylation in melanoma. E3 SUMO ligase targets Tip60, REV1 and p53 for sumoylation to promote p53 activation. PIASy targets histone acetyltransferase for sumoylation, which enhances Tip60 acetylase activity on K120 of p53. PIASy targets directly p53 and leads to K386 sumoylation. The K386-sumoylated and K120-acetylated p53 promoted p53-induced cell death. Moreover, under starvation, PIASy targets DNA polymerase for sumoylation, which contributes to its dissociation from p53 and prevents the REV1-induced inhibition of p53 transactivation. In melanoma, PIASy expression is reduced, thus leading to the inhibition of p53-induced cell death.

Abbreviations: AbK, lysine; Ac, acetylation; P, phosphorylation; SUMO, SUMOylation.