Skip to main content
. Author manuscript; available in PMC: 2010 Aug 2.
Published in final edited form as: Mol Cell Pharmacol. 2010 Jan 1;2(3):117–119.

Figure 1. “The two faces of p53” adapted from Smith and Fornace, 1996, 1997 (3, 4).

Figure 1

The baseline level of DNA damage is never “zero”. Endogenous sources of DNA damage provide a baseline for p53 “activation”. “Activation” is defined as transcriptional induction of p53-regulated effector genes. As DNA damage levels increase, p53 becomes phosphorylated which may promote apoptosis. A number of DNA repair proteins are involved in the p53-mediated protective mechanism, including APE/Ref-1, XPC, gadd45, and Brca1.