FIG. 6.
p48 can be contained in a complex with damaged DNA. V79 cells or 293T cells were transfected with vectors expressing p48 or FLAG-p48. Binding activity was measured with DNA probe damaged at a low dose (300 J/m2) of UV. Extracts (2 μg) from the V79 cells or 293T cells were preincubated with different concentrations of anti-FLAG antibodies (Ab) (10−2 and 10−3 dilutions of stock solution [2 μg/ml]) before initiation of the binding reaction by addition of UV-damaged DNA probe. The upper (V79) and lower (293T) gels were exposed to X-ray film at −80°C for 100 and 16 h, respectively. For the longer exposure, a protein-DNA complex appears in lane 2 of V79 extracts, but this complex was nonspecific, since it was also observed for an undamaged DNA probe (Fig. 1 and 4). F, free DNA probe migration.