The tyrosine phosphorylation of a p72syk-like protein in activated murine resident peritoneal macrophages.
As a marker of macrophage activation, IL-1 alpha was measured after stimulation of murine resident peritoneal macrophages (RPM) with endotoxin-associated protein (EP). Significant IL-1 alpha was produced by EP-stimulated RPM from both C3H/OuJ and C3H/HeJ mouse strains. This EP-mediated IL-1 alpha production was blocked by tyrosine kinase inhibitors including genistein and tyrphostin, suggesting the involvement of a protein tyrosine kinase in the activation of RPM by EP. Immunoblot analysis using antiphosphotyrosine antibody showed that EP induces the tyrosine phosphorylation of a 71 kD protein (p71). The p71 and the spleen tyrosine kinase p72syk found in other cell types share common features including: similar molecular weight, PKC independent tyrosine phosphorylation, and inhibition of phosphorylation by piceatannol. Furthermore, immunoblot analysis using anti-p72syk antibody detected the p72syk kinase in EP-activated RPM. These results suggest that the activation of RPM involves an early tyrosine phosphorylation of p72syk or a p72syk-like protein.
Abu-Lawi
K I
KI
Department of Microbiology and Immunology, State University of New York, Health Science Center at Brooklyn 11203, USA.
Sultzer
B M
BM
D000818:Animals; D001426:Bacterial Proteins / Q000494:pharmacology*; D004731:Endotoxins / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004792:Enzyme Precursors / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D005260:Female; D015151:Immunoblotting; D007370:Interferon Type I / Q000494:pharmacology; D007375:Interleukin-1 / Q000096:biosynthesis*; D047908:Intracellular Signaling Peptides and Proteins; D008050:Lipid A / Q000494:pharmacology*; D008262:Macrophage Activation; D017737:Macrophages, Peritoneal / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D010750:Phosphoproteins / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation; D011257:Pregnancy Proteins / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D015398:Signal Transduction; D000072377:Syk Kinase; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014443:Tyrosine / Q000378:metabolism*
D001426:Bacterial Proteins; D004731:Endotoxins; D004791:Enzyme Inhibitors; D004792:Enzyme Precursors; D007370:Interferon Type I; D007375:Interleukin-1; D047908:Intracellular Signaling Peptides and Proteins; D008050:Lipid A; D010750:Phosphoproteins; D011257:Pregnancy Proteins; D047428:Protein Kinase Inhibitors; C020947:interferon tau; C027315:lipid A-associated protein, Bacteria; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D000072377:Syk Kinase; C000606897:Syk protein, mouse; D013755:Tetradecanoylphorbol Acetate