Calcium-binding myeloid protein (P8,14) is phosphorylated in fMet-Leu-Phe-stimulated neutrophils.
In this report, we show that the p14 subunit of calcium-binding myeloid protein complex (p8,14) is phosphorylated in human neutrophils stimulated with either fMet-Leu-Phe, phorbol myristate acetate, or a calcium ionophore. Trifluoperazine, a calmodulin antagonist, caused hyperphosphorylation of p14 in intact resting neutrophils. Preincubation of resting cells with 10-20 nM calyculin A, a potent protein phosphatase inhibitor, also caused enhanced labeling of p14, which was further progressively increased on stimulation with fMLP. Thus, the phosphorylation level of p14 in resting as well as in stimulated neutrophils appears to be controlled by an active protein phosphatase. The phosphorylation of p14 by a chemoattractant and by a phorbol ester is a novel finding supporting the current belief that p8,14 myeloid protein may play an important role in the metabolism of myeloid cells.
Bengis-Garber
C
C
Department of Biochemistry, Lady Davis Carmel Hospital, Haifa, Israel.
Gruener
N
N
D000001:Calcimycin / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D040501:Calgranulin A; D040502:Calgranulin B; D002147:Calmodulin / Q000037:antagonists & inhibitors; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D039841:Leukocyte L1 Antigen Complex; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation; D011233:Precipitin Tests; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014268:Trifluoperazine / Q000494:pharmacology
D002135:Calcium-Binding Proteins; D040501:Calgranulin A; D040502:Calgranulin B; D002147:Calmodulin; D015816:Cell Adhesion Molecules, Neuronal; D039841:Leukocyte L1 Antigen Complex; D014268:Trifluoperazine; D000001:Calcimycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D013755:Tetradecanoylphorbol Acetate