Airing Out an Antioxidant Role for the Tumor Suppressor p53

Model of concentration-dependent role of p53 in maintaining cell survival or causing apoptosis. Under normal cellular conditions, amounts of ROS are modest and cells experience only mild oxidative stress. In such situations, p53 positively regulates the expression of antiapoptotic genes that lead to cell protection. Under periods of extensive cellular stress, p53 concentrations increase and a new panel of genes are expressed that lead to apoptosis.