Fig. 6.

PARP-1 activity in WT and PARP-1^−/− fibroblast cells infected with Sindbis virus-containing cDNA encoding lacZ or WT PARP-1.A, WT or PARP-1^−/− fibroblasts infected with WT PARP-1 demonstrate prominent PARP-1 activation as quantified by amount of [³²P]NAD incorporated after sonication in the presence of [³²P]NAD.B, PAR polymer formation determined by Western blot indicates that wild-type PARP-1 Sindbis virus restores PARP-1 activity in PARP-1^−/− fibroblasts. Data shown are representative of duplicate experiments.