title: New thioredoxin targets in the unicellular photosynthetic eukaryote Chlamydomonas reinhardtii.
abstract: 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 had been found previously in higher plants or Synechocystis, but 26 were new targets. Biochemical tests were performed on three of them, showing a thioredoxin-dependent activation of isocitrate lyase and isopropylmalate dehydrogenase and a thioredoxin-dependent deactivation of catalase that is redox insensitive in Arabidopsis. In addition, we identified a Ran protein, a previously uncharacterized nuclear target in a photosynthetic organism. The metabolic and evolutionary implications of these findings are discussed.
authors.affiliation: Institut de Biotechnologie des Plantes, Bâtiment 630, Unité Mixte de Recherche 8618, Centre National de la Recherche Scientifique/Université Paris-Sud, F-91405 Orsay-Cedex, France. lemaire@ibp.u-psud.fr
authors.forename: Stéphane D
authors.initials: SD
authors.lastname: Lemaire
authors.forename: Blanche
authors.initials: B
authors.lastname: Guillon
authors.forename: Pierre
authors.initials: P
authors.lastname: Le Maréchal
authors.forename: Eliane
authors.initials: E
authors.lastname: Keryer
authors.forename: Myroslawa
authors.initials: M
authors.lastname: Miginiac-Maslow
authors.forename: Paulette
authors.initials: P
authors.lastname: Decottignies
mesh_terms: D000085:Acetates / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000596:Amino Acids / Q000096:biosynthesis; D000818:Animals; D002244:Carbon / Q000378:metabolism; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D002846:Chromatography, Affinity; D002952:Citric Acid Cycle; D015180:Electrophoresis, Gel, Two-Dimensional; D005227:Fatty Acids / Q000096:biosynthesis; D009584:Nitrogen / Q000378:metabolism; D018384:Oxidative Stress; D010788:Photosynthesis; D014176:Protein Biosynthesis; D017510:Protein Folding; D013455:Sulfur / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism*
chemical_list: D000085:Acetates; D000596:Amino Acids; D005227:Fatty Acids; D013879:Thioredoxins; D013455:Sulfur; D002244:Carbon; D000255:Adenosine Triphosphate; D009584:Nitrogen