Redox regulation of a guard cell SNF1-related protein kinase in Brassica napus, an oilseed crop.
Biochem J
; 474(15): 2585-2599, 2017 07 17.
Article
em En
| MEDLINE
| ID: mdl-28642254
ABSTRACT
Kinase-mediated phosphorylation is a pivotal regulatory process in stomatal responses to stresses. Through a redox proteomics study, a sucrose non-fermenting 1-related protein kinase (SnRK2.4) was identified to be redox-regulated in Brassica napus guard cells upon abscisic acid treatment. There are six genes encoding SnRK2.4 paralogs in B. napus Here, we show that recombinant BnSnRK2.4-1C exhibited autophosphorylation activity and preferentially phosphorylated the N-terminal region of B. napus slow anion channel (BnSLAC1-NT) over generic substrates. The in vitro activity of BnSnRK2.4-1C requires the presence of manganese (Mn2+). Phosphorylation sites of autophosphorylated BnSnRK2.4-1C were mapped, including serine and threonine residues in the activation loop. In vitro BnSnRK2.4-1C autophosphorylation activity was inhibited by oxidants such as H2O2 and recovered by active thioredoxin isoforms, indicating redox regulation of BnSnRK2.4-1C. Thiol-specific isotope tagging followed by mass spectrometry analysis revealed specific cysteine residues responsive to oxidant treatments. The in vivo activity of BnSnRK2.4-1C is inhibited by 15â
min of H2O2 treatment. Taken together, these data indicate that BnSnRK2.4-1C, an SnRK preferentially expressed in guard cells, is redox-regulated with potential roles in guard cell signal transduction.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas Serina-Treonina Quinases
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Produtos Agrícolas
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Brassica napus
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Estômatos de Plantas
Idioma:
En
Revista:
Biochem J
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Estados Unidos