Rapid modification of ribosomal S6 kinase II (S6KII) in rabbit peritoneal neutrophils stimulated with chemotactic factor fMet-Leu-Phe.
The ribosomal S6 kinase II (S6KII) in rabbit neutrophils was studied by immunoblotting with antibodies prepared against recombinant S6KII. A protein with apparent molecular weight of 80,000 Da in SDS-gel was recognized by the antibodies. A shift of the apparent molecular weight to 84,000 Da in SDS-gel was observed in cells stimulated with the chemotactic factor fMet-Leu-Phe. Cytochalasin B and phorbol 12-myristate 13-acetate, but not A23187, stimulated both the tyrosine phosphorylation of p41mapk and the change of the mobility of S6KII. Pretreatment of the cells with quin 2/AM inhibited almost completely the tyrosine phosphorylation of p41mapk induced by fMet-Leu-Phe, but only partially the change in mobility of S6KII. Under various conditions, near maximum conversion of S6KII was observed even if only about 40% of the maximum level of tyrosine phosphorylation of p41mapk was achieved. The results suggest that rapid modification of S6KII occurs in chemotactic factor-stimulated neutrophils. Furthermore, the modification of S6KII induced by fMet-Leu-Phe requires either only partial tyrosine phosphorylation of p41mapk or the activation of kinase(s) other than the p41mapk isoform.
Huang
C K
CK
Department of Pathology, University of Connecticut Health Center, Farmington 06030-3105.
Coleman
H
H
Stevens
T
T
Liang
L
L
D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology*; D010529:Peritoneal Cavity / Q000166:cytology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011817:Rabbits; D019893:Ribosomal Protein S6 Kinases; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D009240:N-Formylmethionine Leucyl-Phenylalanine; D017346:Protein Serine-Threonine Kinases; D019893:Ribosomal Protein S6 Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D013755:Tetradecanoylphorbol Acetate