FIGURE 4.

Silencing of NUDT-5 and -9 reduces AMP accumulation as well as ATP but not NAD depletion during PARP-1 activation. A–C, effect of NUDT-5 and -9 siRNA on their transcript levels (A), cellular NUDIX activity (B), and AMP content in cells under resting conditions or exposed 30 min to MNNG (C). CTRL, control. D and E, impact of NUDT-5 and -9 siRNA on NAD (D) or ATP (E) depletion in cells exposed to MNNG. Bars/points represent the mean ± S.E. of at least three experiments conducted in duplicate. CTR, control. In A, a representative RT-PCR is shown. *, p < 0.05 versus siRNA control; #, p < 0.05 versus siRNA control + MNNG, analysis of variance plus Tukey's post hoc test.