S-Nitrosation of Arabidopsis thaliana Protein Tyrosine Phosphatase 1 Prevents Its Irreversible Oxidation by Hydrogen Peroxide

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Nicolas-Francès, Valérie | Rossi, Jordan | Rosnoblet, Claire | Pichereaux, Carole | Hichami, Siham | Astier, Jeremy | Klinguer, Agnès | Wendehenne, David | Besson-Bard, Angélique

Edité par CCSD ; Frontiers -

International audience. Tyrosine-specific protein tyrosine phosphatases (Tyr-specific PTPases) are key signaling enzymes catalyzing the removal of the phosphate group from phosphorylated tyrosine residues on target proteins. This post-translational modification notably allows the regulation of mitogen-activated protein kinase (MAPK) cascades during defense reactions. Arabidopsis thaliana protein tyrosine phosphatase 1 ( At PTP1), the only Tyr-specific PTPase present in this plant, acts as a repressor of H 2 O 2 production and regulates the activity of MPK3/MPK6 MAPKs by direct dephosphorylation. Here, we report that recombinant histidine (His)- At PTP1 protein activity is directly inhibited by H 2 O 2 and nitric oxide (NO) exogenous treatments. The effects of NO are exerted by S-nitrosation, i.e., the formation of a covalent bond between NO and a reduced cysteine residue. This post-translational modification targets the catalytic cysteine C265 and could protect the At PTP1 protein from its irreversible oxidation by H 2 O 2 . This mechanism of protection could be a conserved mechanism in plant PTPases.

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