title: S-nitrosylation of peroxiredoxin II E promotes peroxynitrite-mediated tyrosine nitration.
abstract: Nitric oxide (NO) is a free radical product of cell metabolism that plays diverse and important roles in the regulation of cellular function. S-Nitrosylation is emerging as a specific and fundamental posttranslational protein modification for the transduction of NO bioactivity, but very little is known about its physiological functions in plants. We investigated the molecular mechanism for S-nitrosylation of peroxiredoxin II E (PrxII E) from Arabidopsis thaliana and found that this posttranslational modification inhibits the hydroperoxide-reducing peroxidase activity of PrxII E, thus revealing a novel regulatory mechanism for peroxiredoxins. Furthermore, we obtained biochemical and genetic evidence that PrxII E functions in detoxifying peroxynitrite (ONOO-), a potent oxidizing and nitrating species formed in a diffusion-limited reaction between NO and O2- that can interfere with Tyr kinase signaling through the nitration of Tyr residues. S-Nitrosylation also inhibits the ONOO- detoxification activity of PrxII E, causing a dramatic increase of ONOO--dependent nitrotyrosine residue formation. The same increase was observed in a prxII E mutant line after exposure to ONOO-, indicating that the PrxII E modulation of ONOO- bioactivity is biologically relevant. We conclude that NO regulates the effects of its own radicals through the S-nitrosylation of crucial components of the antioxidant defense system that function as common triggers for reactive oxygen species- and NO-mediated signaling events.
authors.affiliation: Dipartimento Scientifico e Tecnologico, Università degli Studi di Verona, 37134 Verona, Italy.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Romero-Puertas
authors.forename: Miriam
authors.initials: M
authors.lastname: Laxa
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mattè
authors.forename: Federica
authors.initials: F
authors.lastname: Zaninotto
authors.forename: Iris
authors.initials: I
authors.lastname: Finkemeier
authors.forename: Alex M E
authors.initials: AM
authors.lastname: Jones
authors.forename: Michele
authors.initials: M
authors.lastname: Perazzolli
authors.forename: Elodie
authors.initials: E
authors.lastname: Vandelle
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Dietz
authors.forename: Massimo
authors.initials: M
authors.lastname: Delledonne
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002853:Chromatography, Liquid; D015227:Lipid Peroxidation; D008954:Models, Biological; D009566:Nitrates / Q000737:chemistry / Q000378:metabolism*; D054464:Peroxiredoxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030421:Peroxynitrous Acid / Q000737:chemistry / Q000378:metabolism*; D030821:Plants, Genetically Modified; D053719:Tandem Mass Spectrometry; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D009566:Nitrates; D030421:Peroxynitrous Acid; D014443:Tyrosine; D054464:Peroxiredoxins