Figure 4.

 IR and UV irradiation induce phosphorylation of p53 on serine-15 in both normal and AT lymphoblasts. (A) Western blot analysis of normal and AT lymphoblasts with anti-phosphoserine-15 p53 peptide antibody. Normal lymphoblasts (2184) and AT lymphoblasts (719 and 3332) were untreated (control, C) or given either 5 Gy IR (IR), 5 Gy IR + 20 μm of ALLN (IR + A), 20 μm ALLN (A), or 10 J/m₂ of UV irradiation (UV). Cells were harvested at 1, 3, and 6 hr after treatment. Lysate (50 μg) from each sample was resolved by 10% SDS-PAGE, followed by electrophoretic transfer to nitrocellulose. The nitrocellulose was immunoblotted with anti-phosphoserine-15 p53 peptide antibody. Phosphoserine-15 p53 was detected by ECL. (B) Western blot analysis of normal and AT lymphoblasts with anti-p53. The identical lysates from the above experiment were immunoblotted with anti-p53 antibody (Ab-6). p53 protein was detected with the ECL reagent.