title: CP12-mediated protection of Calvin-Benson cycle enzymes from oxidative stress.
abstract: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and phosphoribulokinase (PRK) are two energy-consuming enzymes of the Calvin-Benson cycle, whose regulation is crucial for the global balance of the photosynthetic process under different environmental conditions. In oxygen phototrophs, GAPDH and PRK regulation involves the redox-sensitive protein CP12. In the dark, oxidized chloroplast thioredoxins trigger the formation of a GAPDH/CP12/PRK complex in which both enzyme activities are down-regulated. In this report, we show that free GAPDH (A4-isoform) and PRK are also inhibited by oxidants like H2O2, GSSG and GSNO. Both in the land plant Arabidopsis thaliana and in the green microalga Chlamydomonas reinhardtii, both enzymes can be glutathionylated as shown by biotinylated-GSSG assay and MALDI-ToF mass spectrometry. CP12 is not glutathionylated but homodisulfides are formed upon oxidant treatments. In Arabidopsis but not in Chlamydomonas, the interaction between oxidized CP12 and GAPDH provides full protection from oxidative damage. In both organisms, preformed GAPDH/CP12/PRK complexes are protected from GSSG or GSNO oxidation, and in Arabidopsis also from H2O2 treatment. Overall, the results suggest that the role of CP12 in oxygen phototrophs needs to be extended beyond light/dark regulation, and include protection of enzymes belonging to Calvin-Benson cycle from oxidative stress.
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Marri
authors.affiliation: Aix Marseille Université (AMU), CNRS, UMR 7281, BIP, 31 Chemin Joseph Aiguier, B.P. 71, 13402 Marseille Cedex 20, France.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Thieulin-Pardo
authors.affiliation: Plate-forme Protéomique, Marseille Protéomique (MaP), Institut de Microbiologie de la Méditerranée, FR 3479, CNRS, 31 Chemin Joseph Aiguier, B.P. 71, 13402 Marseille Cedex 20, France.
authors.forename: Régine
authors.initials: R
authors.lastname: Lebrun
authors.affiliation: Plate-forme Protéomique, Marseille Protéomique (MaP), Institut de Microbiologie de la Méditerranée, FR 3479, CNRS, 31 Chemin Joseph Aiguier, B.P. 71, 13402 Marseille Cedex 20, France.
authors.forename: Rémy
authors.initials: R
authors.lastname: Puppo
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy.
authors.forename: Mirko
authors.initials: M
authors.lastname: Zaffagnini
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy. Electronic address: paolo.trost@unibo.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Trost
authors.affiliation: Aix Marseille Université (AMU), CNRS, UMR 7281, BIP, 31 Chemin Joseph Aiguier, B.P. 71, 13402 Marseille Cedex 20, France. Electronic address: bmeunier@imm.cnrs.fr.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Gontero
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Sparla
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D016825:Chlamydomonas reinhardtii / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D003624:Darkness; D018506:Gene Expression Regulation, Plant; D019803:Glutathione Disulfide / Q000494:pharmacology; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D010788:Photosynthesis / Q000187:drug effects / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D026422:S-Nitrosoglutathione / Q000494:pharmacology; D013045:Species Specificity
chemical_list: D029681:Arabidopsis Proteins; C533605:CP12-1 protein, Arabidopsis; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes; D010940:Plant Proteins; D026422:S-Nitrosoglutathione; D006861:Hydrogen Peroxide; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D017853:Phosphotransferases (Alcohol Group Acceptor); C022390:phosphoribulokinase; D019803:Glutathione Disulfide
keywords: 1,3-bisphosphoglycerate; 5,5-dithiobis(2-nitrobenzoic acid); Arabidopsis thaliana; At; BPGA; Bio-GSSG; Calvin–Benson cycle; Chlamydomonas reinhardtii; Cr; DTNB; DTT; GAPDH; GSH; GSNO; GSSG; Glutathionylation; Grxs; IAM; MALDI-ToF; N-ethylmaleimide; NEM; Oxidative stress; PRK; Protein–protein interaction; TCEP; Thiol-based redox regulation; Tris(2-carboxyethyl)phosphine; Trxs; biotinylated oxidized glutathione; dithiothreitol; glutaredoxins; glyceraldehyde-3-phosphate dehydrogenase; iodoacetamide; matrix-assisted laser-desorption ionization-time-of-flight; nitrosoglutathione; oxidized glutathione; phosphoribulokinase; reduced glutathione; thioredoxins