title: Phosphorylation of the Arabidopsis AtrbohF NADPH oxidase by OST1 protein kinase.
abstract: The plant hormone abscisic acid (ABA) triggers production of reactive oxygen species (ROS) in guard cells via the AtrbohD and AtrbohF NADPH oxidases, leading to stomatal closure. The ABA-activated SnRK2 protein kinase open stomata 1 (OST1) (SRK2E/SnRK2.6) acts upstream of ROS in guard cell ABA signaling. Here, we report that OST1 phosphorylates Ser13 and Ser174 on AtrbohF. In addition, substitution of Ser174 to Ala results in a approximately 40% reduction in the phosphorylation of AtrbohF by OST1. We also show that OST1 physically interacts with AtrbohF. These results provide biochemical evidence suggesting that OST1 regulates AtrbohF activity.
authors.affiliation: Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, UPR 2355, Gif-sur-Yvette, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Sirichandra
authors.forename: Dan
authors.initials: D
authors.lastname: Gu
authors.forename: Heng-Cheng
authors.initials: HC
authors.lastname: Hu
authors.forename: Marlène
authors.initials: M
authors.lastname: Davanture
authors.forename: Sangmee
authors.initials: S
authors.lastname: Lee
authors.forename: Michaël
authors.initials: M
authors.lastname: Djaoui
authors.forename: Benoît
authors.initials: B
authors.lastname: Valot
authors.forename: Michel
authors.initials: M
authors.lastname: Zivy
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Leung
authors.forename: Sylvain
authors.initials: S
authors.lastname: Merlot
authors.forename: June M
authors.initials: JM
authors.lastname: Kwak
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D029681:Arabidopsis Proteins / Q000378:metabolism*; D019255:NADPH Oxidases / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012694:Serine / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D017382:Reactive Oxygen Species; D012694:Serine; D000040:Abscisic Acid; D019255:NADPH Oxidases; D011494:Protein Kinases; C472139:OST1 protein, Arabidopsis