(A) DNA damage induces H2AX ADP-ribosylation. 293T cells were treated with H2O2 (2 mM in PBS, 5 minutes), MMS (1 mM in medium, 30 minutes) or mock (PBS, 30 minutes). ADP-ribosylated proteins were IPed with anti-ADP-ribose (anti-ADPR) antibody. ADP-ribosylated H2AX was examined by Western blotting using anti-H2AX antibody. 