Kinetics of p38 and JNK activation in eosinophils stimulated with eotaxin.

Eosinophils were stimulated and lysed as described for Figure 1. (A) Dual phosphorylation of p38 was detected by Western blotting with antibodies against threonine-tyrosine–phosphorylated p38 (α-PT/PY-p38) (n = 3). (B) p38 was immunoprecipitated from cytosolic extracts and tested in an immune-complex kinase assay using ATF-2 as the substrate. The activation of p38 was in agreement with the kinetics of dual phosphorylation. (C) JNK activation was assessed by Western blotting with antibodies against dual threonine-tyrosine–phosphorylated JNK (α-PT/PY-JNK) (n = 3). Eotaxin failed to stimulate JNK activation above baseline.