title: Reactive oxygen species production and activation mechanism of the rice NADPH oxidase OsRbohB.
abstract: Reactive oxygen species (ROS) produced by plant NADPH oxidases (NOXes) are important in plant innate immunity. The Oryza sativa respiratory burst oxidase homologue B (OsRbohB) gene encodes a NOX the regulatory mechanisms of which are largely unknown. Here, we used a heterologous expression system to demonstrate that OsRbohB shows ROS-producing activity. Treatment with ionomycin, a Ca(2+) ionophore, and calyculin A, a protein phosphatase inhibitor, activated ROS-producing activity; it was thus OsRbohB activated by both Ca(2+) and protein phosphorylation. Mutation analyses revealed that not only the first EF-hand motif but also the upstream amino-terminal region were necessary for Ca(2+)-dependent activation, while these regions are not required for phosphorylation-induced ROS production.
authors.affiliation: Department of Applied Biological Science, Tokyo University of Science, Noda, 278-8510 Chiba, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Takahashi
authors.forename: Sachie
authors.initials: S
authors.lastname: Kimura
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Kaya
authors.forename: Ayako
authors.initials: A
authors.lastname: Iizuka
authors.forename: Hann Ling
authors.initials: HL
authors.lastname: Wong
authors.forename: Ko
authors.initials: K
authors.lastname: Shimamoto
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kuchitsu
mesh_terms: D002118:Calcium / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D015759:Ionomycin / Q000494:pharmacology; D008387:Marine Toxins; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D012275:Oryza / Q000201:enzymology* / Q000378:metabolism; D010080:Oxazoles / Q000494:pharmacology; D010766:Phosphorylation; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014162:Transfection
chemical_list: D008387:Marine Toxins; D010080:Oxazoles; D017382:Reactive Oxygen Species; D015759:Ionomycin; C059041:calyculin A; D019255:NADPH Oxidases; D002118:Calcium