title: A region C-terminal to the proline-rich core of p47phox regulates activation of the phagocyte NADPH oxidase by interacting with the C-terminal SH3 domain of p67phox.
abstract: Activation of the phagocyte NADPH oxidase requires the regulatory proteins p47(phox) and p67(phox), each harboring two SH3 domains. p67(phox) interacts with p47(phox) via simultaneous binding of the p67(phox) C-terminal SH3 domain to both the proline-rich region (PRR) of amino acid residues 360-369 and its C-terminally flanking region of p47(phox); the role of the interaction in oxidase regulation has not been fully understood. Here we show that the p47(phox)-p67(phox) interaction is disrupted not only by deletion of the PRR but also by substitution for basic residues in the extra-PRR (K383E/K385E). The substitution impaired oxidase activation partially in vitro and much more profoundly in vivo, indicating the significance of the p47(phox) extra-PRR. Replacement of Ser-379 in the extra-PRR, a residue known to undergo phosphorylation in stimulated cells, by aspartate attenuates the interaction and thus results in a defective superoxide production, suggesting that phosphorylation of Ser-379 is involved in oxidase regulation.
authors.affiliation: Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Mizuki
authors.forename: Ryu
authors.initials: R
authors.lastname: Takeya
authors.forename: Futoshi
authors.initials: F
authors.lastname: Kuribayashi
authors.forename: Ikuo
authors.initials: I
authors.lastname: Nobuhisa
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kohda
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nunoi
authors.forename: Koichiro
authors.initials: K
authors.lastname: Takeshige
authors.forename: Hideki
authors.initials: H
authors.lastname: Sumimoto
mesh_terms: D019943:Amino Acid Substitution; D002478:Cells, Cultured; D004789:Enzyme Activation; D006801:Humans; D019255:NADPH Oxidases / Q000378:metabolism*; D009504:Neutrophils / Q000378:metabolism*; D010587:Phagocytosis / Q000502:physiology*; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D011392:Proline / Q000737:chemistry / Q000378:metabolism*; D025941:Protein Interaction Mapping / Q000379:methods*; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship
chemical_list: D010750:Phosphoproteins; C079789:neutrophil cytosol factor 67K; D011392:Proline; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1