(F) Western blot analysis of PARP1 accumulation on chromatin. EWS-WT and M4 mutants were transfected into EWS depleted HEK-293 cells. After treatment of MMS (0.02%, 1 hour), the proteins were fractionated to either chromatin-bound or soluble fraction. (G) Quantification of relative amount of PARP1 and γH2AX on chromatin, divided by chromatin H3, from three independent western experiments are presented. Data represented as mean ±SEMs, were measured from 3 independent experiments. Significance determined by t-test. * P < 0.05, **P < 0.01. n.s indicate non-significance 