NTR/NRX Define a New Thioredoxin System in the Nucleus of Arabidopsis thaliana Cells

作     者：Corinne Marchal Valerie Delorme-Hinoux Laetitia Bariat Wafi Siala Christophe Belin Julio Saez-Vasquez Christophe Riondet Jean-Philippe Reichheld 

作者机构：Universite Perpignan Via Domitia CNRS Laboratoire Genome et Developpement des Plantes UMR 5096 58 Avenue Paul Alduy-Bat T F-66860 Perpignan France Pharmacologie cellulaire et moleculaire Louvain Drug Research Institute Universite catholique de Louvain Brussels Belgium 

出 版 物：《Molecular Plant》 (分子植物（英文版）)

年 卷 期：2014年第7卷第1期

页      面：30-44页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 07[理学] 071009[理学-细胞生物学] 0901[农学-作物学] 0902[农学-园艺学] 

基　　金：supported by the Centre National de la Recherche Scientifique  the Agence Nationale de la Recherche 

主　　题：thioredoxin nucleoredoxin nucleus Arabidopsis. 

摘      要：Thioredoxins （TRX） are key components of cellular redox balance, regulating many target proteins through thiol/disulfide exchange reactions. In higher plants, TRX constitute a complex multigenic family whose members have been found in almost all cellular compartments. Although chloroplastic and cytosolic TRX systems have been largely studied, the presence of a nuclear TRX system has been elusive for a long time. Nucleoredoxins （NRX） are potential nuclear TRX found in most eukaryotic organisms. In contrast to mammals, which harbor a unique NRX, angiosperms gen- erally possess multiple NRX organized in three subfamilies. Here, we show thatArabidopsis thaliana has two NRXgenes （AtNRX1 and AtNRX2）, respectively, belonging to subgroups I and III. While NRX1 harbors typical TRX active sites （WCG/ PPC）, NRX2 has atypical active sites （WCRPC and WCPPF）. Nevertheless, both NRXl and NRX2 have disulfide reduction capacities, although NRX1 alone can be reduced by the thioredoxin reductase NTRA. We also show that both NRX1 and NRX2 have a dual nuclear/cytosolic localization. Interestingly, we found that NTRA, previously identified as a cytosolic protein, is also partially localized in the nucleus, suggesting that a complete TRX system is functional in the nucleus. We show that NRX1 is mainly found as a dimer in vivo. nrxl and nrx2 knockout mutant plants exhibit no phenotypic perturbations under standard growth conditions. However, the nrxl mutant shows a reduced pollen fertility phenotype, suggesting a specific role of NRX1 at the haploid phase.