Effect of Ro-31-8220 on phosphorylation of ERKs after stimulation with anti-IgE Ab or FMLP.

Basophils were preincubated with DMSO (1:10 000 dilution) or Ro-31-8220 (1 μmol/L) for 10 minutes and were stimulated with or without anti-IgE Ab (0.5 μg/mL) for 10 minutes or PMA (50 ng/mL) for 20 minutes. Reactions were stopped with the addition of ice-cold PAG, and the cells were microfuged. Cell pellets were lysed and subjected to Western blot analysis as described in “Materials and methods.” The anti-ERK1 and anti-ERK2 blots indicated essentially equal protein loading (data not shown). The Western blot shown is representative of 2 separate experiments.