title: Reconstitution of GTPgammaS-induced NADPH oxidase activity in streptolysin-O-permeabilized neutrophils by specific cytosol fractions.
abstract: GTPgammaS activates the NADPH oxidase and this activity declines rapidly with time after preexposure to streptolysin O. This was not due to loss of p47(phox), p67(phox), or Rac. To identify the component(s) leaking out of the permeabilized cell responsible for loss of activity, a GTPgammaS-dependent reconstitution assay was established. Neutrophil cytosol was subjected to chromatographic fractionation steps for purification of the minimum fraction required to restore activity. The reconstitution of the GTPgammaS-stimulated activity was dependent on ATP. The inhibitors staurosporine and calphostin C greatly reduced the activity in the reconstitution assay, implicating the involvement of a protein kinase C (PKC) pathway. PKC isoforms beta and delta were eliminated as the active factors in the most pure reconstitution fraction. With this novel cell-based reconstitution assay, we have identified the requirement for a protein kinase, or its substrate, for the restoration of GTPgammaS activation of the NADPH oxidase.
authors.affiliation: Department of Physiology, University College London, London, United Kingdom.
authors.forename: L
authors.initials: L
authors.lastname: Leino
authors.forename: L
authors.initials: L
authors.lastname: Forbes
authors.forename: A
authors.initials: A
authors.lastname: Segal
authors.forename: S
authors.initials: S
authors.lastname: Cockcroft
mesh_terms: D001426:Bacterial Proteins; D002463:Cell Membrane Permeability; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D003600:Cytosol / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D019255:NADPH Oxidases / Q000097:blood* / Q000302:isolation & purification; D009504:Neutrophils / Q000201:enzymology / Q000378:metabolism*; D010750:Phosphoproteins / Q000097:blood* / Q000302:isolation & purification; D010766:Phosphorylation; D013301:Streptolysins; D013481:Superoxides / Q000097:blood
chemical_list: D001426:Bacterial Proteins; D010750:Phosphoproteins; D013301:Streptolysins; C079789:neutrophil cytosol factor 67K; C025964:streptolysin O; D013481:Superoxides; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1