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

Kazuhito Mizuki, Ryu Takeya, Futoshi Kuribayashi, Ikuo Nobuhisa, Daisuke Kohda, Hiroyuki Nunoi, Koichiro Takeshige, Hideki Sumimoto

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Activation of the phagocyte NADPH oxidase requires the regulatory proteins p47phox and p67phox, each harboring two SH3 domains. p67phox interacts with p47phox via simultaneous binding of the p67phox C-terminal SH3 domain to both the proline-rich region (PRR) of amino acid residues 360-369 and its C-terminally flanking region of p47phox; the role of the interaction in oxidase regulation has not been fully understood. Here we show that the p47phox-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 p47phox 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.

Original languageEnglish
Pages (from-to)185-194
Number of pages10
JournalArchives of Biochemistry and Biophysics
Issue number2
Publication statusPublished - Dec 15 2005


All Science Journal Classification (ASJC) codes

  • Biophysics
  • Biochemistry
  • Molecular Biology

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