The role of thioredoxin TrxA in Bacillus subtilis:: A proteomics and transcriptomics approach
The role of thioredoxin TrxA in Bacillus subtilis:: A proteomics and transcriptomics approach
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DOI：
10.1002/pmic.200701015
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发表时间：
2008-07-01
期刊：
影响因子：
3.4
通讯作者：
Hecker, Michael
中科院分区：
文献类型：
--
作者：
Mostertz, Joerg;Hochgraefe, Falko;Hecker, Michael
硫氧还蛋白超家族的硫醇-二硫化物氧化还原酶对于维持活生物体中的硫醇氧化还原状态至关重要。枯草芽孢杆菌硫氧还蛋白A（TrxA）是一种重要基因的产物，在细菌生长过程中起着关键作用。通过mRNA谱分析，Smits等人（J. Bacteriol. 2005，187，3921-3930）提出了TrxA在稳定期期间的硫利用中的关键功能。我们扩展了分析的TrxA指数增长和特征的trxA条件突变体的蛋白质组分析补充转录组学。TrxA耗尽后，生长速率显著降低。细胞在mRNA和蛋白质水平上通过增加参与硫利用的基因的表达来响应，这代表了基于凝胶的蛋白质组学所观察到的最明显的响应。此外，几个抗氧化反应的基因被发现在较高的表达水平后TrxA耗尽。当硫代硫酸盐或蛋氨酸代替硫酸盐作为硫源时，抑制作用消失。在硫代硫酸盐的存在下，但在没有TrxA的情况下，硫限制反应和氧化应激反应的诱导没有观察到。我们的结果表明，基因表达的整体变化主要是由TrxA耗尽后硫酸盐利用的中断引起的。因此，其在硫酸盐同化中的功能使得TrxA成为生长B的必需蛋白。枯草杆菌细胞
Thiol-disulfide oxidoreductases of the thioredoxin superfamily are crucial for maintaining the thiol redox state in living organisms. For the bacterium Bacillus subtilis thioredoxin A (TrxA) was described as the product of an essential gene indicating a key role during growth. By means of mRNA profiling Smits et al. (J. Bacteriol. 2005, 187, 3921-3930) suggested a critical function for TrxA in sulfur utilization during stationary phase. We extended the analysis of TrxA to exponential growth and characterized a trxA conditional mutant by proteome analysis complemented by transcriptomics. After TrxA-depletion, the growth rate was dramatically decreased. The cells responded at mRNA and protein level by the increased expression of genes involved in the utilization of sulfur, which represents the most obvious response as visualized by gel-based proteomics. Furthermore, several genes of the antioxidant response were found at higher expression levels after TrxA-depletion. When sulfate was replaced by thiosulfate or methionine as sulfur source, the growth inhibition was abolished. In the presence of thiosulfate but in the absence of TrxA, the induction of the sulfur limitation response and the oxidative stress response was not observed. Our results show that the global change of gene expression is primarily caused by the interruption of the sulfate utilization after TrxA depletion. Thus, its function in sulfate assimilation renders TrxA an essential protein in growing B. subtilis cells.