FIG. 1.
Azacytidine activates p125 in hamster cells. Human cell lines (HeLa and XPE− cell lines, 2415 and 82TO) and wild-type hamster cell lines (K1, V79, and AA8) were grown in medium with azacytidine omitted (A) or added (B). Whole-cell extracts (2 μg) were then assayed for damage-specific binding activity with DNA probes either damaged with 5,000 J/m2 UV (+) or left undamaged (−). Panels A and B each show one gel exposed to X-ray film at −80°C for 12 h (lanes 1 to 3) or 72 h (lanes 4 to 13). F marks the migration of free DNA probe, and B1 and B2 mark the mobilities of protein-DNA complexes specific for UV damage. The protein-DNA complexes in lanes 2 and 6 are nonspecific, since they are observed for the undamaged DNA probes.