title: The CBL-interacting protein kinase CIPK26 is a novel interactor of Arabidopsis NADPH oxidase AtRbohF that negatively modulates its ROS-producing activity in a heterologous expression system.
abstract: The plant NADPH oxidases, known as respiratory burst oxidase homologues (Rbohs), play an indispensable role in a wide array of cellular and developmental processes. Arabidopsis thaliana RbohF (AtRbohF)-mediated production of reactive oxygen species (ROS) is involved in biotic and abiotic stress responses. Because of the toxicity of excess amount of ROS, the ROS-producing activity of Rbohs is speculated to be negatively regulated. However, its mechanism is mostly unknown to date. Here, we report the identification of calcineurin B-like protein-interacting protein kinase 26 (CIPK26) as a novel regulatory factor of AtRbohF. We isolated CIPK26 as an AtRbohF-interacting partner by a yeast two-hybrid screen. Our co-immunoprecipitation assay revealed that the CIPK26 protein interacts with the N-terminal region of AtRbohF in Nicotiana benthamiana cell extracts. The fluorescence of both GFP-tagged CIPK26 and AtRbohF was predominantly observed at the cell periphery. We also showed that co-expression of CIPK26 decreases the ROS-producing activity of AtRbohF in HEK293T cells. Together, these results suggest that the direct binding of CIPK26 to AtRbohF negatively modulates ROS production and play a role in the regulation of ROS signalling in plants.
authors.affiliation: Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba, Japan.
authors.forename: Sachie
authors.initials: S
authors.lastname: Kimura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kawarazaki
authors.forename: Hitomi
authors.initials: H
authors.lastname: Nibori
authors.forename: Masataka
authors.initials: M
authors.lastname: Michikawa
authors.forename: Aya
authors.initials: A
authors.lastname: Imai
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Kaya
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kuchitsu
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D017382:Reactive Oxygen Species