| Project/Area Number |
09670134
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General medical chemistry
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
SUMIMOTO Hideki KYUSHU UNIV., SCH.MEDICINE,PROFFESOR, 医学部, 教授 (30179303)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1998: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1997: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | SH3 Domain / p47^<phox> / p67^<phox> / NADPH Oxidase / p40^<phox> / Rac / Cytochrome b_<558> / Rac. / シトクローム=_<558> / p22^<phox> / 殺菌 / スーパーオキシド |
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| Research Abstract |
In this project we have studied molecular mechanism by which p47^<phox> and p67^<phox>, each containing two SH3 domains, activate the phagocyte NADPH oxidase, to obtain the following results. (1) The SH3 domains of p47^<phox> are masked via intramolecular interaction with its C-terminal region. The interaction is disrupted by arachidonic acid or by phosphorylation of three serine residues in the p47^<phox> C-terminus, which allows the domains to bind to cytochrome b_<558>, the enzymatic core of the oxidase. The intermolecular interaction functions as a switch for the oxidase activation. (2) The two SH3 domains are tandemly arranged with a linker of 10 amino acid residues. The length of the linker plays an important role in both intramolecular and intermolecular interactions. (3) Another switch for the activation is conversion of the small GTPase Rac to the GTP-bound active state, which leads to interaction with p67^<phox>. This binding is mediated via the TPR domain of the latter protein. (4) We have developed a novel method to detect the GTP-bound Rac at a cell level. Using this procedure, we find that Rac activation of human neutrophils stimulated with G1-coupled receptor agonists requires phosphoinositide 3-kinase. (5) Discovered is a novel module in the N-terminus of p47P^<phox>, designated PB2 domain, that positively regulates the oxidase activation. (6) The oxidase regulator p4O^<phox> constitutively associates with p67^<phox>, which is mediated via a novel type of interaction between two modules that are discoverd in this project : the PB 1 domain of p67PhOx and the PC motif of p40^<phox>.
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