Characterization of the redox properties of poplar glutaredoxin.
The presence of glutaredoxins in plants is now well recognized, but their functions and natural substrates remain largely unknown. Recently, a poplar glutaredoxin has been biochemically characterized and several mutants have been engineered in order to explore its reactivity. This work focuses on some physiological functions of the enzyme. According to our findings, the poplar glutaredoxin can serve as an electron donor to the bacterial 3'-phosphoadenylylsulfate reductase as it supports both the catalysis by the enzyme in vitro and complements a methionine auxotroph strain of Escherichia coli. In addition, poplar glutaredoxin is able to reduce the Escherichia coli ribonucleotide reductase 1a (in vitro reduction of cytidine diphosphate). Although this glutaredoxin is described as an electron donor to a phloem-located peroxiredoxin, whose function is to detoxify hydroperoxides, we found that it does not directly reduce hydrogen peroxide or other alkyl hydroperoxides as described for yeast and rice glutaredoxins. However, the poplar glutaredoxin may be involved in the response to oxidative stress as its overexpression in Escherichia coli resulted in a higher resistance toward hydrogen peroxide, menadione, and tert-butyl hydroperoxide.
Rouhier
Nicolas
N
Unité Mixte de Recherche 1136 IaM, INRA-UHP Nancy I. Université Henri Poincaré, 54506 Vandoeuvre Cedex, France.
Vlamis-Gardikas
Alexios
A
Lillig
Christopher Horst
CH
Berndt
Carsten
C
Schwenn
Jens-Dirk
JD
Holmgren
Arne
A
Jacquot
Jean-Pierre
JP
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003565:Cytidine Diphosphate / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004583:Electrons; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D054477:Glutaredoxins; D006861:Hydrogen Peroxide / Q000378:metabolism; D007700:Kinetics; D008954:Models, Biological; D008969:Molecular Sequence Data; D012275:Oryza / Q000378:metabolism; D016877:Oxidants / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism; D054464:Peroxiredoxins; D010724:Phosphoadenosine Phosphosulfate / Q000737:chemistry; D010802:Phylogeny; D032107:Populus / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D024483:Vitamin K 3 / Q000378:metabolism
D005656:Fungal Proteins; D054477:Glutaredoxins; D016877:Oxidants; D011506:Proteins; D010724:Phosphoadenosine Phosphosulfate; D003565:Cytidine Diphosphate; D024483:Vitamin K 3; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D010544:Peroxidases; D054464:Peroxiredoxins; D050862:Oxidoreductases Acting on Sulfur Group Donors; C019618:adenylylsulfate reductase