Figure 3

Accumulation of p53 protein. Equal numbers of cells were exposed to 10 Gy of IR and 50 J/m² of UV light, respectively, and incubated for up to 6 h. Whole cells were lysed and an equal volume of protein extracts were subjected to Western blot analysis using anti-p53 antibody. p53 protein accumulation in OPL-2 cells was delayed after IR exposure and abrogated after UV exposure. In Pal-1 cells, p53 was not activated following IR or UV exposure. In control cell lines, OPL-7 and IB4, p53 protein accumulated as expected after IR and UV exposure. Equivalence of loading of cell lysates is shown by anti-β-actin labeling.