title: Post-translational modifications of Medicago truncatula glutathione peroxidase 1 induced by nitric oxide.
abstract: Plant glutathione peroxidases (Gpx) catalyse the reduction of various peroxides, such as hydrogen peroxide (H2O2), phospholipid hydroperoxides and peroxynitrite, but at the expense of thioredoxins rather than glutathione. A main function of plant Gpxs is the protection of biological membranes by scavenging phospholipid hydroperoxides, but some Gpxs have also been associated with H2O2sensing and redox signal transduction. Nitric oxide (NO) is not only known to induce the expression of Gpx family members, but also to inhibit Gpx activity, presumably through the S-nitrosylation of conserved cysteine residues. In the present study, the effects of NO-donors on both the activity and S-nitrosylation state of purified Medicago truncatula Gpx1 were analyzed using biochemical assay measurements and a biotin-switch/mass spectrometry approach. MtGpx1 activity was only moderately inhibited by the NO-donors diethylamine-NONOate and S-nitrosoglutathione, and the inhibition may be reversed by DTT. The three conserved Cys of MtGpx1 were found to be modified through S-nitrosylation and S-glutathionylation, although to different extents, by diethylamine-NONOate and S-nitrosoglutathione, or by a combination of diethylamine-NONOate and reduced glutathione. The regulation of MtGpx1 and its possible involvement in the signaling process is discussed in the light of these results.
authors.affiliation: UMR INRA 1355, CNRS 7254, Université Nice Sophia Antipolis, Institut Sophia Agrobiotech, 06903 Sophia Antipolis Cedex, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Castella
authors.affiliation: Department of Biochemistry & Biotechnology, Laboratory of Plant & Environmental Biotechnology, University of Thessaly, Biopolis, 41500 Larissa, Greece.
authors.forename: Ioanna
authors.initials: I
authors.lastname: Mirtziou
authors.affiliation: UMR INRA 1355, CNRS 7254, Université Nice Sophia Antipolis, Institut Sophia Agrobiotech, 06903 Sophia Antipolis Cedex, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Seassau
authors.affiliation: UMR INRA 1355, CNRS 7254, Université Nice Sophia Antipolis, Institut Sophia Agrobiotech, 06903 Sophia Antipolis Cedex, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Boscari
authors.affiliation: IRHS, Université d'Angers, INRA, AGROCAMPUS-Ouest, SFR 4207 QUASAV, 42 rue Georges Morel, 49071 Beaucouzé cedex, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Montrichard
authors.affiliation: Department of Biochemistry & Biotechnology, Laboratory of Plant & Environmental Biotechnology, University of Thessaly, Biopolis, 41500 Larissa, Greece.
authors.forename: Kalliopi
authors.initials: K
authors.lastname: Papadopoulou
authors.affiliation: UMR 1136 Interactions Arbres-Microorganismes, Université de Lorraine/INRA, F-54500 Vandoeuvre-lès-Nancy, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rouhier
authors.affiliation: UMR INRA 1355, CNRS 7254, Université Nice Sophia Antipolis, Institut Sophia Agrobiotech, 06903 Sophia Antipolis Cedex, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Puppo
authors.affiliation: UMR INRA 1355, CNRS 7254, Université Nice Sophia Antipolis, Institut Sophia Agrobiotech, 06903 Sophia Antipolis Cedex, France. Electronic address: renaud.brouquisse@inra.fr.
authors.forename: Renaud
authors.initials: R
authors.lastname: Brouquisse
mesh_terms: D000595:Amino Acid Sequence; D008401:Gas Chromatography-Mass Spectrometry; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism*; D046913:Medicago truncatula / Q000187:drug effects*; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D000094765:Glutathione Peroxidase GPX1
chemical_list: D009569:Nitric Oxide; D005979:Glutathione Peroxidase; D000094765:Glutathione Peroxidase GPX1
keywords: Glutathione peroxidase; Medicago truncatula; Nitric oxide; S-glutathionylation; S-nitrosylation