Regulation of p53 family members by the ubiquitin-like SUMO system.

p53 and its cousins p63 and p73 are critical regulators of the genotoxic stress response in mammalian cells. Their activity is controlled by an intricate network of post-translational modifications. The ubiquitin-like SUMO system targets all three family members and modulates their transcriptional activity, stability or subcellular trafficking. While the SUMO system appears to primarily exert a negative regulatory function on p73 and p63, both activating and repressing activities have been reported on p53. Here we will give a synopsis of the multifaceted effects of SUMO on p53 family members.