Figure 4.

PARP3 and PARP2 modify 5′- or 3′-terminal phosphates of the opposite strands at DSB termini depending on the distance from the nick. (A) Denaturing PAGE analysis of PARP-generated products of ADP-ribosylation of [³²P]labeled nicked RexT sequence-based duplexes. ADP-ribosylation of 3′-unlabeled or 5′-terminally [³²P]labeled phosphates of 40mer matrix strand was assessed by additional treatment with 10 U of CIP for 30 min at 37°C (lanes 9, 11, 14 and 16). (B) Schematic representation of the putative model of DNA modification by PARP2 or PARP3.