Selective Role for β-Protein Kinase C in Signaling for O⨪2 Generation but Not Degranulation or Adherence in Differentiated HL60 Cells

• Published in: The Journal of biological chemistry 1998-10, Vol.273 (42), p.27292-27299
• Main Authors: Korchak, Helen M., Rossi, Michael W., Kilpatrick, Laurie E.
• Format: Article
• Language: English
• Subjects: Biological Transport; Cell Adhesion; Cell Degranulation; Cell Differentiation; Fibronectins - metabolism; HL-60 Cells; Humans; Isoenzymes - genetics; Isoenzymes - metabolism; Ligands; N-Formylmethionine Leucyl-Phenylalanine - pharmacology; NADPH Oxidases; Neutrophils - metabolism; Oligonucleotides, Antisense; Phosphoproteins - metabolism; Phosphorylation; Protein Kinase C - genetics; Protein Kinase C - metabolism; Protein Kinase C beta; Protein Kinase C-alpha; Protein Kinase C-delta; Reactive Oxygen Species - metabolism; Signal Transduction; Superoxides - metabolism; Tetradecanoylphorbol Acetate - pharmacology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.273.42.27292

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 β-PKC, both βI- and βII-PKC, but not α-PKC, δ-PKC, or ζ-PKC in HL60 cells differentiated to a neutrophil-like phenotype (dHL60 cells). Depletion of β-PKC in dHL60 cells elicited selective inhibition of O⨪2generation triggered by fMet-Leu-Phe, immune complexes, or phorbol myristate acetate, an activator of PKC. In contrast, neither ligand-elicited β-glucuronidase (azurophil granule) release nor adherence to fibronectin was inhibited by β-PKC depletion. Ligand-induced phosphorylation of a subset of proteins was reduced in β-PKC-depleted dHL60 cells. Phosphorylation of p47phox and translocation of p47phox to the membrane are essential for activation of the NADPH oxidase and generation of O⨪2. β-PKC depletion had no effect on the level of p47phoxin dHL60 cells but did significantly decrease ligand-induced phosphorylation of this protein. Furthermore, translocation of p47phox to the membrane in response to phorbol myristate acetate or fMet-Leu-Phe was reduced in β-PKC-depleted cells. These results indicate that β-PKC is essential for signaling for O⨪2 generation but not cell adherence or azurophil degranulation. Depletion of β-PKC inhibited ligand-induced phosphorylation of p47phox, translocation of p47phox to the membrane, and activation of O⨪2 generation.