title: A redox-sensitive cysteine residue regulates the kinase activities of OsMPK3 and OsMPK6 in vitro.
abstract: Two subgroup A rice mitogen-activated protein kinases (MAPKs), OsMPK3 and OsMPK6, have been implicated in multiple stress responses. However, the redox-control of the kinase activity of these proteins remains unknown. Here, immunoprecipitated OsMPK3 and OsMPK6 were initially activated in 15min, and this activation transiently increased in rice seedlings under H2O2 stress. Among the six conserved cysteine residues, only the fourth cysteine residues in the kinase domain VII, Cys(179) and Cys(210), were required for the in vitro kinase activities of OsMPK3 and OsMPK6, respectively. Moreover, the substitution of these specific cysteine residues with serine abrogated in vitro kinase responses to redox conditions. These results suggest a novel redox-control mechanism for the kinase activities of these MAPKs in vivo.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China. Electronic address: xiegsh@mail.hzau.edu.cn.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Xie
authors.affiliation: Crop Breeding Division, Hokkaido Agricultural Research Center, National Agricultural and Food Research Organization, Hitsujigaoka 1, Toyohira-ku, Sapporo 062-8555, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: Crop Breeding Division, Hokkaido Agricultural Research Center, National Agricultural and Food Research Organization, Hitsujigaoka 1, Toyohira-ku, Sapporo 062-8555, Japan.
authors.forename: Ryozo
authors.initials: R
authors.lastname: Imai
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Deying
authors.initials: D
authors.lastname: Xie
mesh_terms: D000222:Adaptation, Physiological; D003545:Cysteine / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D012275:Oryza / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010940:Plant Proteins / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D006861:Hydrogen Peroxide; D020928:Mitogen-Activated Protein Kinases; D003545:Cysteine
keywords: In vitro kinase activity; MAPK; Redox-control; Rice; Site-directed mutagenesis