Chloroplasts lacking class I glutaredoxins are functional but show a delayed recovery of protein cysteinyl redox state after oxidative challenge.

Autor: Bohle F; Molecular Botany, Department of Biology, RPTU Kaiserslautern-Landau, D-67633, Kaiserslautern, Germany; Chemical Signalling, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, D-53113, Bonn, Germany., Rossi J; Department of Pharmacy and Biotechnology, University of Bologna, I-40126, Bologna, Italy., Tamanna SS; Molecular Botany, Department of Biology, RPTU Kaiserslautern-Landau, D-67633, Kaiserslautern, Germany., Jansohn H; Molecular Botany, Department of Biology, RPTU Kaiserslautern-Landau, D-67633, Kaiserslautern, Germany., Schlosser M; Molecular Botany, Department of Biology, RPTU Kaiserslautern-Landau, D-67633, Kaiserslautern, Germany., Reinhardt F; Plant Physiology, Department of Biology, RPTU Kaiserslautern-Landau, D-67633, Kaiserslautern, Germany., Brox A; Crop Functional Genomics, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, D-53113, Bonn, Germany., Bethmann S; Plant Biochemistry, Heinrich-Heine-University Düsseldorf, D-40225, Düsseldorf, Germany., Kopriva S; Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Cologne, 50674, Germany., Trentmann O; Molecular Botany, Department of Biology, RPTU Kaiserslautern-Landau, D-67633, Kaiserslautern, Germany., Jahns P; Plant Biochemistry, Heinrich-Heine-University Düsseldorf, D-40225, Düsseldorf, Germany., Deponte M; Biochemistry, Department of Chemistry, RPTU Kaiserslautern-Landau, D-67633, Kaiserslautern, Germany., Schwarzländer M; Institute of Plant Biology and Biotechnology, University of Münster, D-48143, Münster, Germany., Trost P; Department of Pharmacy and Biotechnology, University of Bologna, I-40126, Bologna, Italy., Zaffagnini M; Department of Pharmacy and Biotechnology, University of Bologna, I-40126, Bologna, Italy., Meyer AJ; Chemical Signalling, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, D-53113, Bonn, Germany., Müller-Schüssele SJ; Molecular Botany, Department of Biology, RPTU Kaiserslautern-Landau, D-67633, Kaiserslautern, Germany. Electronic address: mueschue@rptu.de.
Jazyk: angličtina
Zdroj: Redox biology [Redox Biol] 2024 Feb; Vol. 69, pp. 103015. Date of Electronic Publication: 2023 Dec 28.
DOI: 10.1016/j.redox.2023.103015
Abstrakt: Redox status of protein cysteinyl residues is mediated via glutathione (GSH)/glutaredoxin (GRX) and thioredoxin (TRX)-dependent redox cascades. An oxidative challenge can induce post-translational protein modifications on thiols, such as protein S-glutathionylation. Class I GRX are small thiol-disulfide oxidoreductases that reversibly catalyse S-glutathionylation and protein disulfide formation. TRX and GSH/GRX redox systems can provide partial backup for each other in several subcellular compartments, but not in the plastid stroma where TRX/light-dependent redox regulation of primary metabolism takes place. While the stromal TRX system has been studied at detail, the role of class I GRX on plastid redox processes is still unknown. We generate knockout lines of GRXC5 as the only chloroplast class I GRX of the moss Physcomitrium patens. While we find that PpGRXC5 has high activities in GSH-dependent oxidoreductase assays using hydroxyethyl disulfide or redox-sensitive GFP2 as substrates in vitro, Δgrxc5 plants show no detectable growth defect or stress sensitivity, in contrast to mutants with a less negative stromal E GSH (Δgr1). Using stroma-targeted roGFP2, we show increased protein Cys steady state oxidation and decreased reduction rates after oxidative challenge in Δgrxc5 plants in vivo, indicating kinetic uncoupling of the protein Cys redox state from E GSH . Compared to wildtype, protein Cys disulfide formation rates and S-glutathionylation levels after H 2 O 2 treatment remained unchanged. Lack of class I GRX function in the stroma did not result in impaired carbon fixation. Our observations suggest specific roles for GRXC5 in the efficient transfer of electrons from GSH to target protein Cys as well as negligible cross-talk with metabolic regulation via the TRX system. We propose a model for stromal class I GRX function in efficient catalysis of protein dithiol/disulfide equilibria upon redox steady state alterations affecting stromal E GSH and highlight the importance of identifying in vivo target proteins of GRXC5.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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