Pertussis toxin inhibits the FMLP-induced membrane association of protein kinase C in human neutrophils.

The effect of pertussis toxin on N-formyl-methionyl-leucyl-phenylalanine (FMLP), phorbol 12-myristate 13-acetate (PMA), ionomycin, and A23187-induced translocation of protein kinase C and superoxide generation was studied in human neutrophils. Pertussis toxin was shown to inhibit FMLP-induced superoxide generation in parallel with an inhibition of protein kinase C translocation. In contrast, no effect of pertussis toxin was demonstrated upon superoxide generation or protein kinase C translocation in PMA-, A23187-, or ionomycin-stimulated cells. In that superoxide generation and protein kinase C translocation were inhibited in parallel, it is concluded that a G-protein-dependent cascade is involved in the FMLP-induced activation of protein kinase C, and this cascade may be equivalent to the pathway inducing superoxide generation.