p53, Guardian of the Genome

Abstract

p53 is the most important tumor suppressor. It arrests cell cycle in response to stress, stimulates DNA repair, and induces senescence or apoptosis of cells that have unrepairable damage. p53 level and activity are kept low by the E3 ubiquitin ligase Mdm2, which ubiquitinates p53 targeting it for proteasomal degradation. Additional post-translational modifications of p53 such as phosphorylation, methylation, acetylation, and others, signal the cell’s internal condition to p53 and modulate its activity.

Keywords: ATM, ATR, Apoptosis, Cell cycle, Cell cycle arrest, Cancer, DNA damage, Mdm2, p53, p63, p73, Tumor suppressor.