The Maintenance of Epigenetic States by p53: The Guardian of the Epigenome

Copyright: © Levine et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The functions of the p53 tumor suppressor gene and its protein are to ensure fidelity of cellular replicative processes so as to minimize mutational errors even in the presence of a wide variety of environmental stresses. Among the stresses p53 senses and responds to are DNA damage including telomere erosion, hypoxia, nutrient deprivation, errors in ribosomal biogenesis, abnormal chromosome segregation and even the mutational activation of several diverse oncogenes. Each of these stresses increases the rate of mutagenesis and the frequencies of cancers. When a cell senses a stress, it signals to the p53 protein using a wide variety of protein modifications (phosphorylation, acetylation, methylation)