p53 Moves Into Control of Cell Morphology

p53 functions as a tumor suppressor gene. A. In unstressed wild-type cells, the activity of p53 is relatively low, and its degradation is promoted by MDM2. Genotoxic stress leads to the activation of p53, resulting in cell cycle arrest or apoptosis, and a reduction in Cdc42-dependent microspikes. B. In tumor cells p53 is often mutated, or degraded owing to increased MDM2 activity. This leads to deregulated cell proliferation, failure to undergo apoptosis, and an increase in Cdc42-dependent functions. MDM2, murine double minute 2.