Concanavalin A stimulation of O2 consumption in electropermeabilized neutrophils via a pertussis toxin-insensitive G protein.
Electropermeabilized human neutrophils were used to investigate the possible role of G-proteins in the respiratory burst elicited by concanavalin A (Con A). The Con A-induced activation of the NADPH oxidase was not inhibited by either pertussis toxin or cholera toxin. However, the burst was inhibited by GDP and GDP beta S providing evidence for the involvement of a G-protein(s). O2 consumption in Con A-stimulated cells was dependent on both ATP and Mg2+. ATP could be substituted by ATP gamma S but not by the non-hydrolyzable analog AMP-PNP, suggesting involvement of phosphotransferase reactions. It is concluded that at least two distinct types of G-proteins are capable of inducing the respiratory burst in neutrophils and that accumulation of phosphorylated intermediates may be essential for activation of the respiratory burst by the lectin.
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Division of Cell Biology, Hospital for Sick Children, Toronto, Canada.
Grinstein
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D000255:Adenosine Triphosphate / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects; D003208:Concanavalin A / Q000494:pharmacology*; D004560:Electricity; D019204:GTP-Binding Proteins / Q000502:physiology*; D006150:Guanine Nucleotides / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009249:NADP / Q000502:physiology; D009504:Neutrophils / Q000502:physiology*; D010101:Oxygen Consumption / Q000187:drug effects; D037342:Pertussis Toxin; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D006150:Guanine Nucleotides; D010566:Virulence Factors, Bordetella; D003208:Concanavalin A; D009249:NADP; D009240:N-Formylmethionine Leucyl-Phenylalanine; D000255:Adenosine Triphosphate; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D008274:Magnesium