Myroslawa Miginiac-Maslow

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The sequencing of the genome of Arabidopsis thaliana revealed that this plant contained numerous isoforms of thioredoxin (Trx), a protein involved in thiol-disulfide exchanges. On the basis of sequence comparison, seven putative chloroplastic Trxs have been identified, four belonging to the m-type, two belonging to the f-type, and one belonging to a new(More)
Photorespiration is a light-dependent source of H(2)O(2) in the peroxisomes, where concentrations of this signalling molecule are regulated by catalase. Growth of Arabidopsis knock-out mutants for CATALASE2 (cat2) in ambient air caused severely decreased rosette biomass, intracellular redox perturbation and activation of oxidative signalling pathways. These(More)
Peroxiredoxin Q (Prx Q) is one out of 10 peroxiredoxins encoded in the genome of Arabidopsis thaliana, and one out of four that are targeted to plastids. Peroxiredoxin Q functions as a monomeric protein and represents about 0.3% of chloroplast proteins. It attaches to the thylakoid membrane and is detected in preparations enriched in photosystem II(More)
Proteomics were used to identify the proteins from the eukaryotic unicellular green alga Chlamydomonas reinhardtii that can be reduced by thioredoxin. These proteins were retained specifically on a thioredoxin affinity column made of a monocysteinic thioredoxin mutant able to form mixed disulfides with its targets. Of a total of 55 identified targets, 29(More)
The sequencing of the Arabidopsis genome revealed a multiplicity of thioredoxins (TRX), ubiquitous protein disulfide oxido-reductases. We have analyzed the TRX family in the genome of the unicellular green alga Chlamydomonas reinhardtii and identified eight different thioredoxins for which we have cloned and sequenced the corresponding cDNAs. One of these(More)
Proteomics was used to search for putative thioredoxin (TRX) targets in leaves of the model plant, Arabidopsis thaliana. About forty different proteins have been found to be reduced by TRX, after TRX itself has been specifically reduced by its NADPH-dependent reductase. Twenty-one of the identified proteins were already known or recently proposed to be(More)
Sunlight provides the energy source for the assimilation of carbon dioxide by photosynthesis, but it also provides regulatory signals that switch on specific sets of enzymes involved in the alternation of light and dark metabolisms in chloroplasts. Capture of photons by chlorophyll pigments triggers redox cascades that ultimately activate target enzymes via(More)
Five different clones encoding thioredoxin homologues were isolated from Arabidopsis thaliana cDNA libraries. On the basis of the sequences they encode divergent proteins, but all belong to the cytoplasmic thioredoxins h previously described in higher plants. The five proteins obtained by overexpressing the coding sequences in Escherichia coli present(More)
The Calvin cycle enzymes glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and phosphoribulokinase (PRK) can form under oxidizing conditions a supramolecular complex with the regulatory protein CP12. Both GAPDH and PRK activities are inhibited within the complex, but they can be fully restored by reduced thioredoxins (TRXs). We have investigated the(More)
Some key chloroplast enzymes are activated by light via a ferredoxin-thioredoxin reduction system which reduces disulfide bridges in the enzymes. We describe for the first time the structural basis for the redox activation of a chloroplast enzyme, the NADP-dependent malate dehydrogenase (MDH) from Sorghum vulgare whose structure has been determined and(More)