| 1. |
- Gama, Filipe, et al.
(författare)
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The mitochondrial type II peroxiredoxin from poplar
- 2007
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Ingår i: Physiologia Plantarum. - Copenhagen : Blackwell Munksgaard. - 0031-9317 .- 1399-3054. ; 129:1, s. 196-206
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondria are a major site of reactive oxygen species production and controlling the peroxide levels in this compartment is essential. Peroxiredoxins (Prx) are heme-free peroxidases, which use reactive cysteines for their catalysis and reducing systems for their regeneration. One of the two Prxs present in poplar mitochondria, Prx IIF, expressed as a recombinant protein, was found to reduce a broad range of peroxides with electrons provided preferentially by glutaredoxin and to a lesser extent by glutathione, all the thioredoxins tested being inefficient. This protein is constitutively expressed because it is found in all tissues analyzed. Its expression is modified during a biotic interaction between poplar and the rust fungus Melampsora laricii populina. On the other hand, Prx IIF expression does not substantially vary under abiotic stress conditions. Nevertheless, water deficit or chilling and probably induced senescence, but not photooxidative conditions or heavy metal treatment, also led to a small increase in PrxIIF abundance in Arabidopsis thaliana plants.
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| 2. |
- Møller, Ian Max, et al.
(författare)
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Matrix Redox Physiology Governs the Regulation of Plant Mitochondrial Metabolism through Posttranslational Protein Modifications
- 2020
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Ingår i: The Plant cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 32:3, s. 573-594
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Forskningsöversikt (refereegranskat)abstract
- Mitochondria function as hubs of plant metabolism. Oxidative phosphorylation produces ATP, but it is also a central high-capacity electron sink required by many metabolic pathways that must be flexibly coordinated and integrated. Here, we review the crucial roles of redox-associated posttranslational protein modifications (PTMs) in mitochondrial metabolic regulation. We discuss several major concepts. First, the major redox couples in the mitochondrial matrix (NAD, NADP, thioredoxin, glutathione, and ascorbate) are in kinetic steady state rather than thermodynamic equilibrium. Second, targeted proteomics have produced long lists of proteins potentially regulated by Cys oxidation/thioredoxin, Met-SO formation, phosphorylation, or Lys acetylation, but we currently only understand the functional importance of a few of these PTMs. Some site modifications may represent molecular noise caused by spurious reactions. Third, different PTMs on the same protein or on different proteins in the same metabolic pathway can interact to fine-tune metabolic regulation. Fourth, PTMs take part in the repair of stress-induced damage (e.g., by reducing Met and Cys oxidation products) as well as adjusting metabolic functions in response to environmental variation, such as changes in light irradiance or oxygen availability. Finally, PTMs form a multidimensional regulatory system that provides the speed and flexibility needed for mitochondrial coordination far beyond that provided by changes in nuclear gene expression alone.
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| 3. |
- Rouhier, Nicolas, et al.
(författare)
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Identification of plant glutaredoxin targets
- 2005
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Ingår i: Antioxidants and Redox Signaling. - Larchmont, NY : Mary Ann Liebert. - 1523-0864 .- 1557-7716. ; 7:7-8, s. 919-929
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Tidskriftsartikel (refereegranskat)abstract
- Glutaredoxins (Grxs) are small ubiquitous proteins of the thioredoxin (Trx) family, which catalyze dithiol–disulfide exchange reactions or reduce protein-mixed glutathione disulfides. In plants, several Trx-interacting proteins have been isolated from different compartments, whereas very few Grx-interacting proteins are known. We describe here the determination of Grx target proteins using a mutated poplar Grx, various tissular and subcellular plant extracts, and liquid chromatography coupled to tandem mass spectrometry detection. We have identified 94 putative targets, involved in many processes, including oxidative stress response [peroxiredoxins (Prxs), ascorbate peroxidase, catalase], nitrogen, sulfur, and carbon metabolisms (methionine synthase, alanine aminotransferase, phosphoglycerate kinase), translation (elongation factors E and Tu), or protein folding (heat shock protein 70). Some of these proteins were previously found to interact with Trx or to be glutathiolated in other organisms, but others could be more specific partners of Grx. To substantiate further these data, Grx was shown to support catalysis of the stroma β-type carbonic anhydrase and Prx IIF of Arabidopsis thaliana, but not of poplar 2-Cys Prx. Overall, these data suggest that the interaction could occur randomly either with exposed cysteinyl disulfide bonds formed within or between target proteins or with mixed disulfides between a protein thiol and glutathione.
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