1. Post-translational modifications of Medicago truncatula glutathione peroxidase 1 induced by nitric oxide.
- Author
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Castella C, Mirtziou I, Seassau A, Boscari A, Montrichard F, Papadopoulou K, Rouhier N, Puppo A, and Brouquisse R
- Subjects
- Amino Acid Sequence, Gas Chromatography-Mass Spectrometry, Glutathione Peroxidase genetics, Nitric Oxide metabolism, Glutathione Peroxidase GPX1, Glutathione Peroxidase metabolism, Medicago truncatula drug effects, Nitric Oxide pharmacology, Protein Processing, Post-Translational drug effects
- Abstract
Plant glutathione peroxidases (Gpx) catalyse the reduction of various peroxides, such as hydrogen peroxide (H
2 O2 ), 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 H2 O2 sensing 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., (Copyright © 2017 Elsevier Inc. All rights reserved.)- Published
- 2017
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