Figure 5. BRCA1 BRCT mutants expressed from HD-Ad vectors enter the nucleus of HCC1937 cells. (A) HCC1937 cells infected with the indicated HD-Ad vectors were examined for BRCA1 nuclear localization by FLAG immuno-staining after 4 Gy irradiation. Representative nuclei are shown. (B) HCC1937 cells infected with the indicated HD-Ad vectors were treated as in A and fractionated to examine FLAG-BRCA1 localization by western blot analysis. DNA-PKcs was used as a marker for determining the yield and efficiency into nuclear and cytoplasmic fractions.