Thioredoxin h2 contributes to the redox regulation of mitochondrial photorespiratory metabolism
Autor: | Wagner L. Araújo, Danilo M. Daloso, Saskia Schwab, Paulo V L Souza, Alisdair R. Fernie, Adriano Nunes-Nesi, Stefan Timm, Ina Thormählen, Paula da Fonseca-Pereira, Peter Geigenberger, Liang-Yu Hou |
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Jazyk: | angličtina |
Rok vydání: | 2020 |
Předmět: |
animal structures
Physiology Cell Respiration Thioredoxin h Arabidopsis Plant Science Mitochondrion Gene Expression Regulation Plant Photosynthesis Glycine Hydroxymethyltransferase Chemistry Arabidopsis Proteins Chlorophyll A Metabolism Carbon Dioxide Glycine Dehydrogenase (Decarboxylating) Mitochondria Plant Leaves Cytosol Biochemistry Serine hydroxymethyltransferase Glycine Photorespiration NAD+ kinase Thioredoxin Transcriptome Oxidation-Reduction |
Zdroj: | Plant, Cell and Environment |
Popis: | Thioredoxins (TRX) are important proteins involved in redox regulation of metabolism. In plants, it has been shown that the mitochondrial metabolism is regulated by the mitochondrial TRX system. However, the functional significance of TRX h2, which is found at both cytosol and mitochondria, remains unclear. Arabidopsis plants lacking TRX h2 showed delayed seed germination and reduced respiration alongside impaired stomatal and mesophyll conductance, without impacting photosynthesis under ambient O2 conditions. However, an increase in the stoichiometry of photorespiratory CO2 release was found during O2-dependent gas exchange measurements in trxh2 mutants. Metabolite profiling of trxh2 leaves revealed alterations in key metabolites of photorespiration and in several metabolites involved in respiration and amino acid metabolism. Decreased abundance of serine hydroxymethyltransferase and glycine decarboxylase (GDC) H and L subunits as well as reduced NADH/NAD+ ratios were also observed in trxh2 mutants. We further demonstrated that the redox status of GDC-L is altered in trxh2 mutants in vivo and that recombinant TRX h2 can deactivate GDC-L in vitro, indicating that this protein is redox regulated by the TRX system. Collectively, our results demonstrate that TRX h2 plays an important role in the redox regulation of mitochondrial photorespiratory metabolism. |
Databáze: | OpenAIRE |
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