Cholera and pertussis toxins abrogate the s-FKN–induced ERKs and p38 activations, but do not affect the JNK1 activation.

MonoMac6 cells, untreated or preincubated 4 hours with 250 ng/mL pertussis toxin (PTX) or 10 μg/mL cholera toxin (CTX), were exposed to 60 nM s-FKN following different time courses. The activity and the amount of each MAPK were evaluated as previously described in Figure 1and in “Materials and methods.” The results are representative of 3 experiments.