Differential molecular response of monodehydroascorbate reductase and glutathione reductase by nitration and S-nitrosylation
| Autor: | Mounira Chaki, María N. Padilla, Javier Lopez-Jaramillo, Francisco Luque, Juan B. Barroso, Raquel Valderrama, Capilla Mata-Pérez, Beatriz Sánchez-Calvo, Juan C. Begara-Morales, Francisco J. Corpas |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Salinity
Antioxidant Chloroplasts Nitration Physiology medicine.medical_treatment Glutathione reductase Plant Science Reductase Nitric Oxide peroxynitrite Peroxynitrite salinity S-Nitrosoglutathione chemistry.chemical_compound S-nitrosoglutathione Cytosol medicine NADH NADPH Oxidoreductases Reactive nitrogen species Plant Proteins biology Chemistry Monodehydroascorbate reductase Peas Nitric oxide Glutathione Sequence Analysis DNA Peroxisome nitration S-nitrosylation monodehydroascorbate reductase reactive nitrogen species Glutathione Reductase Biochemistry biology.protein Protein Processing Post-Translational Peroxidase Research Paper |
| Zdroj: | Digibug. Repositorio Institucional de la Universidad de Granada instname Digibug: Repositorio Institucional de la Universidad de Granada Universidad de Granada (UGR) Journal of Experimental Botany |
| DOI: | 10.1093/jxb/erv306 |
| Popis: | The ascorbate–glutathione cycle is a metabolic pathway that detoxifies hydrogen peroxide and involves enzymatic and non-enzymatic antioxidants. Proteomic studies have shown that some enzymes in this cycle such as ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), and glutathione reductase (GR) are potential targets for post-translational modifications (PMTs) mediated by nitric oxide-derived molecules. Using purified recombinant pea peroxisomal MDAR and cytosolic and chloroplastic GR enzymes produced in Escherichia coli, the effects of peroxynitrite (ONOO–) and S-nitrosoglutathione (GSNO) which are known to mediate protein nitration and S-nitrosylation processes, respectively, were analysed. Although ONOO– and GSNO inhibit peroxisomal MDAR activity, chloroplastic and cytosolic GR were not affected by these molecules. Mass spectrometric analysis of the nitrated MDAR revealed that Tyr213, Try292, and Tyr345 were exclusively nitrated to 3-nitrotyrosine by ONOO–. The location of these residues in the structure of pea peroxisomal MDAR reveals that Tyr345 is found at 3.3 Å of His313 which is involved in the NADPbinding site. Site-directed mutagenesis confirmed Tyr345 as the primary site of nitration responsible for the inhibition of MDAR activity by ONOO–. These results provide new insights into the molecular regulation of MDAR which is deactivated by nitration and S-nitrosylation. However, GR was not affected by ONOO– or GSNO, suggesting the existence of a mechanism to conserve redox status by maintaining the level of reduced GSH. Under a nitro-oxidative stress induced by salinity (150 mM NaCl), MDAR expression (mRNA, protein, and enzyme activity levels) was increased, probably to compensate the inhibitory effects of S-nitrosylation and nitration on the enzyme. The present data show the modulation of the antioxidative response of key enzymes in the ascorbate–glutathione cycle by nitric oxide (NO)- PTMs, thus indicating the close involvement of NO and reactive oxygen species metabolism in antioxidant defence against nitro-oxidative stress situations in plants. Spanish Government ERDF - Ministry of Economy and Competitiveness BIO2012-33904 Junta de Andalucía BIO286 BIO192 |
| Databáze: | OpenAIRE |
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