PMID- 1381363 OWN - NLM STAT- MEDLINE DCOM- 19921007 LR - 20210210 IS - 0021-9258 (Print) IS - 0021-9258 (Linking) VI - 267 IP - 25 DP - 1992 Sep 5 TI - Chemoattractant-induced tyrosine phosphorylation and activation of microtubule-associated protein kinase in human neutrophils. PG - 18122-5 AB - Activation of human neutrophils by the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (fMLP) induces tyrosine phosphorylation of several polypeptides, including a prominent band of approximately 41 kDa. A polypeptide of identical electrophoretic mobility was recognized by a monoclonal antibody raised against a sequence corresponding to amino acids 325-345 of ERK-1, one of a family of mitogen-activated protein (MAP) kinases. To establish the possible identity of these polypeptides, extracts from control and fMLP-treated cells were immunoprecipitated with immobilized antiphosphotyrosine antibodies. Reactivity with anti-ERK-1 antibodies was observed only in the precipitate of chemoattractant-stimulated cells. These data imply that a MAP kinase constitutes at least part of the tyrosine-phosphorylated 41-kDa polypeptide. By using an in vitro renaturation assay, treatment of intact cells with fMLP was found to stimulate several protein kinases, including one of approximately 41 kDa. Renaturation of samples immunoprecipitated with antiphosphotyrosine antibodies revealed the presence of an active protein kinase in chemoattractant-stimulated, but not in control cells. The immunoprecipitated kinase comigrated with the 41-kDa tyrosine phosphorylated polypeptide and the anti-ERK-1 reactive band. We conclude that a MAP kinase closely related or identical to ERK-1 is tyrosine phosphorylated and activated when human neutrophils are stimulated by chemotactic peptides. The rapid phosphorylation of this kinase, which is apparent within seconds, is compatible with a role in the activation of the respiratory burst and/or other neutrophil responses. FAU - Grinstein, S AU - Grinstein S AD - Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada. FAU - Furuya, W AU - Furuya W LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't PL - United States TA - J Biol Chem JT - The Journal of biological chemistry JID - 2985121R RN - 0 (Phosphoproteins) RN - 21820-51-9 (Phosphotyrosine) RN - 42HK56048U (Tyrosine) RN - 59880-97-6 (N-Formylmethionine Leucyl-Phenylalanine) RN - EC 2.7.- (Protein Kinases) RN - EC 2.7.11.17 (Calcium-Calmodulin-Dependent Protein Kinases) SB - IM MH - Blotting, Western MH - Calcium-Calmodulin-Dependent Protein Kinases MH - Enzyme Activation MH - Humans MH - In Vitro Techniques MH - Kinetics MH - Molecular Weight MH - N-Formylmethionine Leucyl-Phenylalanine/*pharmacology MH - Neutrophils/drug effects/*metabolism MH - Phosphoproteins/*blood/isolation & purification MH - Phosphorylation MH - Phosphotyrosine MH - Protein Kinases/*blood MH - Tyrosine/analogs & derivatives/analysis EDAT- 1992/09/05 00:00 MHDA- 1992/09/05 00:01 CRDT- 1992/09/05 00:00 PHST- 1992/09/05 00:00 [pubmed] PHST- 1992/09/05 00:01 [medline] PHST- 1992/09/05 00:00 [entrez] AID - S0021-9258(19)37161-3 [pii] PST - ppublish SO - J Biol Chem. 1992 Sep 5;267(25):18122-5.