Fig. 6. Cyclin B2 and Aurora-A phosphorylation is independent of PP1 inhibition. The same extracts as in Fig. 5 were used. Prophase extracts were depleted (C and D) or not (A and B) in PP2A by incubation with microcystin-agarose beads. After centrifugation, the extracts were incubated in the presence (B and D) or absence (A and C) of 500 nM P-DARPP-32 at 30°C in the absence (–) or in the presence of an ATP-regenerating system (ATP) plus or minus okadaic acid (OA). Samples were collected at indicated times and analysed by western blotting with the anti-Cyclin B2 antibody, the anti-Aurora-A antibody, the anti-P-Aurora-A antibody, the DARPP-32 antibody, the anti-P-DARPP-32 antibody, the PP1 antibody and the PP2A antibodies, as indicated.