NADPH Thioredoxin Reductase C Controls the Redox Status of Chloroplast 2-Cys Peroxiredoxins in Arabidopsis thaliana

作     者：Kerstin Kirchsteiger Pablo Pulido Maricruz Gonzalez Francisco Javier Cejudo 

作者机构：Instituto de Bioquimica Vegetal y Fotosintesis Universidad de Sevilla and CSIC Avda Americo Vespucio 49 41092-Sevilla Spain 

出 版 物：《Molecular Plant》 (分子植物（英文版）)

年 卷 期：2009年第2卷第2期

页      面：298-307页

核心收录：

学科分类：09[农学] 0903[农学-农业资源与环境] 090302[农学-植物营养学] 

基　　金：grant BIO2007-60644 from Ministerio de Education y Ciencia (Spain) 

主　　题：Chloroplast peroxiredoxin NADPH thioredoxin reductase C overoxidation thioredoxin Arabidopsis. 

摘      要：Chloroplast 2-Cys peroxiredoxins （2-Cys Prxs） are efficiently reduced by NADPH Thioredoxin reductase C （NTRC）. To investigate the effect of light/darkness on NTRC function, the content of abundant plastidial enzymes, Rubisco, glutamine synthetase （GS）, and 2-Cys Prxs was analyzed during two consecutive days in Arabidopsis wild-type and ntrc mutant plants. No significant difference of the content of these proteins was observed during the day or the night in wildtype and mutant plants. NTRC deficiency caused a lower content of fully reduced 2-Cys Prxs, which was undetectable in darkness, suggesting that NTRC is the most important pathway for 2-Cys Prx reduction, probably the only one during the night. Arabidopsis contains two plastidial 2-Cys Prxs, A and B, for which T-DNA insertion lines were characterized showing the same phenotype as wild-type plants. Two-dimensional gel analysis of leaf extracts from these mutants allowed the identification of basic and acidic isoforms of 2-Cys Prx A and B. In-vitro assays and mass spectrometry analysis showed that the acidic isoform of both proteins is produced by overoxidation of the peroxidatic Cys residue to sulfinic acid. 2-Cys Prx overoxidation was lower in the NTRC mutant. These results show the important function of NTRC to maintain the redox equilibrium of chloroplast 2-Cys Prxs.