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

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

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.807249

DOI=10.3389/fpls.2022.807249

ISSN=1664-462X

ABSTRACT=<p>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. <italic>Arabidopsis thaliana</italic> protein tyrosine phosphatase 1 (<italic>At</italic>PTP1), the only Tyr-specific PTPase present in this plant, acts as a repressor of H<sub>2</sub>O<sub>2</sub> production and regulates the activity of MPK3/MPK6 MAPKs by direct dephosphorylation. Here, we report that recombinant histidine (His)-<italic>At</italic>PTP1 protein activity is directly inhibited by H<sub>2</sub>O<sub>2</sub> 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 <italic>At</italic>PTP1 protein from its irreversible oxidation by H<sub>2</sub>O<sub>2</sub>. This mechanism of protection could be a conserved mechanism in plant PTPases.</p>