The effect of cell-intrinsic factors on the p53 response. (A-B) We correlated the half-life of 53BP1 foci (A) and basal p53-Venus levels prior to damage (B) with the presence or absence of a p53 pulse in individual cells (blue line: robust linear fit, shaded blue area: confidence interval at α = 0.05). For visualization, we plotted the fraction of cells inducing a p53 pulse after damage binned according to their half-life of 53BP1 foci (A, bin size W = two hours, blue dots) or basal p53-Venus level prior to damage (B, bin size W = 50 au, blue dots). The number of cells in each bin is indicated by grey bars. Number of cells = approximately 300. (C) Cell cycle distribution of cells that induce a p53 pulse (light blue) or do not pulse (dark blue) after damage (50 ng/ml NCS). P-value 0.6337, Kolmogorov-Smirnov test (D) The number of induced DSBs and the resulting p53 response are correlated (blue line: robust linear fit, shaded blue area: confidence interval at α = 0.05). The fraction of cells inducing a p53 pulse after damage is plotted for cells binned according to the number of induced 53BP1 foci (bin size W = four foci, blue dots). For each bin, the percentage of cells in S/G2 phases is indicated by grey bars. Cells were classified into G1 and S/G2 groups based on their normalized DAPI fluorescence (G1 cells: <0.33 normalized DAPI fluorescence units and S/G2 cells: > = 0.33 normalized DAPI fluorescence units). Number of cells = 270.
Loewer et al. BMC Biology 2013 11:114 doi:10.1186/1741-7007-11-114