MAP Kinase Expression in Eosinophils

The mitogen-activated protein kinases (MAPK) are an expanding family of proline-directed serine/threonine kinases that are activated, following their dual phosphorylation at conserved threonine and tyrosine residues, by a family of MAPK kinases (MEK). Presently, the MAPK family can be divided into three groups: the extracellular signal-regulated kinases (ERK), composed of ERK-1/2/3/4/5, the c-jun N-terminal kinases (JNK)-46/54; and the p38 MAP kinase (p38 MAPK) composed of p38/p38β/p38γ/p38δ (1). Of these enzymes, the authors have detected ERK-1/2/3/5, JNK-46/54, and p38 in guinea pig peritoneal eosinophils by Western analysis: ERK-4 and p38β were apparently absent.