Selective role for beta-protein kinase C in signaling for O-2 generation but not degranulation or adherence in differentiated HL60 cells.
A role for protein kinase C (PKC) isotypes is implicated in the activation of phagocytic cell functions. An antisense approach was used to selectively deplete beta-PKC, both betaI- and betaII-PKC, but not alpha-PKC, delta-PKC, or zeta-PKC in HL60 cells differentiated to a neutrophil-like phenotype (dHL60 cells). Depletion of beta-PKC in dHL60 cells elicited selective inhibition of O-2 generation triggered by fMet-Leu-Phe, immune complexes, or phorbol myristate acetate, an activator of PKC. In contrast, neither ligand-elicited beta-glucuronidase (azurophil granule) release nor adherence to fibronectin was inhibited by beta-PKC depletion. Ligand-induced phosphorylation of a subset of proteins was reduced in beta-PKC-depleted dHL60 cells. Phosphorylation of p47(phox) and translocation of p47(phox) to the membrane are essential for activation of the NADPH oxidase and generation of O-2. beta-PKC depletion had no effect on the level of p47(phox) in dHL60 cells but did significantly decrease ligand-induced phosphorylation of this protein. Furthermore, translocation of p47(phox) to the membrane in response to phorbol myristate acetate or fMet-Leu-Phe was reduced in beta-PKC-depleted cells. These results indicate that beta-PKC is essential for signaling for O-2 generation but not cell adherence or azurophil degranulation. Depletion of beta-PKC inhibited ligand-induced phosphorylation of p47(phox), translocation of p47(phox) to the membrane, and activation of O-2 generation.
Korchak
H M
HM
Departments of Pediatrics, University of Pennsylvania School of Medicine, The Joseph Stokes Jr. Research Institute of the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA. Korchak@email.chop.edu
Rossi
M W
MW
Kilpatrick
L E
LE
D001692:Biological Transport; D002448:Cell Adhesion; D015550:Cell Degranulation; D002454:Cell Differentiation; D005353:Fibronectins / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D019255:NADPH Oxidases; D009504:Neutrophils / Q000378:metabolism*; D016376:Oligonucleotides, Antisense; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D064546:Protein Kinase C beta; D051571:Protein Kinase C-alpha; D051745:Protein Kinase C-delta; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction; D013481:Superoxides / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D000099221:Protein Kinase C zeta
D005353:Fibronectins; D007527:Isoenzymes; D008024:Ligands; D009240:N-Formylmethionine Leucyl-Phenylalanine; D019255:NADPH Oxidases; D016376:Oligonucleotides, Antisense; D010750:Phosphoproteins; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D051571:Protein Kinase C-alpha; D051745:Protein Kinase C-delta; D017382:Reactive Oxygen Species; D013481:Superoxides; D013755:Tetradecanoylphorbol Acetate; D000099221:Protein Kinase C zeta; C060505:neutrophil cytosolic factor 1; C496628:PRKCA protein, human; C497258:PRKCD protein, human