title: NADPH-dependent thioredoxin reductase and 2-Cys peroxiredoxins are needed for the protection of Mg-protoporphyrin monomethyl ester cyclase.
abstract: The chloroplast-localized NADPH-dependent thioredoxin reductase (NTRC) has been found to be able to reduce hydrogen peroxide scavenging 2-Cys peroxiredoxins. We show that the Arabidopsis ntrc mutant is perturbed in chlorophyll biosynthesis and accumulate intermediates preceding protochlorophyllide formation. A specific involvement of NTRC during biosynthesis of protochlorophyllide is indicated from in vitro aerobic cyclase assays in which the conversion of Mg-protoporhyrin monomethyl ester into protochlorophyllide is stimulated by addition of the NTRC/2-Cys peroxiredoxin system. These findings support the hypothesis that this NADPH-dependent hydrogen peroxide scavenging system is particularly important during periods with limited reducing power from photosynthesis, e.g. under chloroplast biogenesis.
authors.affiliation: VKR Research Centre Pro-Active Plants, Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Anne
authors.initials: A
authors.lastname: Stenbaek
authors.forename: Andreas
authors.initials: A
authors.lastname: Hansson
authors.forename: Ragna Peterson
authors.initials: RP
authors.lastname: Wulff
authors.forename: Mats
authors.initials: M
authors.lastname: Hansson
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Dietz
authors.forename: Poul Erik
authors.initials: PE
authors.lastname: Jensen
mesh_terms: D000332:Aerobiosis; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002734:Chlorophyll / Q000096:biosynthesis* / Q000235:genetics; D010105:Oxygenases / Q000378:metabolism*; D054464:Peroxiredoxins / Q000378:metabolism*; D013880:Thioredoxin-Disulfide Reductase / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D002734:Chlorophyll; D054464:Peroxiredoxins; D010105:Oxygenases; C053161:magnesium protoporphyrin monomethyl ester oxidative cyclase; C000612940:NTRC protein, Arabidopsis; D013880:Thioredoxin-Disulfide Reductase