title: Proteomic identification of glyceraldehyde 3-phosphate dehydrogenase as an inhibitory target of hydrogen peroxide in Arabidopsis.
abstract: Hydrogen peroxide (H2O2) is now recognised as a key signalling molecule in eukaryotes. In plants, H2O2 is involved in regulating stomatal closure, gravitropic responses, gene expression and programmed cell death. Although several kinases, such as oxidative signal-inducible 1 (OXI1) kinase and mitogen-activated protein kinases are known to be activated by exogenous H2O2, little is known about the proteins that directly react with H2O2. Here, we utilised a proteomic approach, using iodoacetamide-based fluorescence tagging of proteins in conjunction with mass spectrometric analysis, to identify several proteins that might be potential targets of H2O2 in the cytosolic fraction of Arabidopsis thaliana, the most prominent of which was cytosolic glyceraldehyde 3-phosphate dehydrogenase (cGAPDH; EC 1.2.1.12). cGAPDH from Arabidopsis is inactivated by H2O2 in vitro, and this inhibition is reversible by the subsequent addition of reductants such as reduced glutathione (GSH). It has been suggested recently that Arabidopsis GAPDH has roles outside of its catalysis as part of glycolysis, while in other systems this includes that of mediating reactive oxygen species (ROS) signalling. Here, we suggest that cGAPDH in Arabidopsis might also have such a role in mediating ROS signalling in plants.
authors.affiliation: Centre for Research in Plant Science, Genomics Research Institute, Faculty of Applied Sciences, University of the West of England, Bristol, Coldharbour Lane, Bristol BS16 1QY, UK. john.hancock@uwe.ac.uk
authors.forename: John T
authors.initials: JT
authors.lastname: Hancock
authors.forename: Dan
authors.initials: D
authors.lastname: Henson
authors.forename: Mukanthu
authors.initials: M
authors.lastname: Nyirenda
authors.forename: Radhika
authors.initials: R
authors.lastname: Desikan
authors.forename: Judith
authors.initials: J
authors.lastname: Harrison
authors.forename: Mervyn
authors.initials: M
authors.lastname: Lewis
authors.forename: Jenna
authors.initials: J
authors.lastname: Hughes
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Neill
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008969:Molecular Sequence Data; D020543:Proteome; D017386:Sequence Homology, Amino Acid; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D020543:Proteome; D006861:Hydrogen Peroxide; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases