Spx is a global effector impacting stress tolerance and biofilm formation in Staphylococcus aureus
Spx is a global effector impacting stress tolerance and biofilm formation in Staphylococcus aureus
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DOI：
10.1128/jb.00194-06
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发表时间：
2006-07-01
影响因子：
3.2
通讯作者：
Ingmer, Hanne
中科院分区：
文献类型：
--
作者：
Pamp, Sunje Johanna;Frees, Dorte;Ingmer, Hanne
在枯草芽孢杆菌中，Spx最近被表征为一种新型的全局调节剂，其活性受细胞的氧化还原状态调节。在本研究中，我们证明了重要病原体金黄色葡萄球菌中Spx的失活使细胞对广泛的应激条件（包括高温和低温、高渗透压和过氧化氢）超敏感。此外，在非胁迫条件下，生长受到限制。二维凝胶电泳显示，spx突变体的蛋白质组与野生型细胞的蛋白质组有很大不同，这支持了Spx也是S.金黄色。更具体地说，我们证明，Spx是必需的转录trxB，编码硫氧还蛋白还原酶，在所有的生长条件下检查。由于trxB在S.金黄色葡萄球菌，我们推测，trxB转录的严重减少可以解释spx突变体的一些生长缺陷。spx的失活也促进了生物膜的形成。S.金黄色葡萄球菌生物膜的形成与伊卡操纵子编码的多糖细胞间粘附素的产生有关。有趣的是，我们的数据表明，spx突变体形成生物膜的能力增强是由于Spx调节icaR的表达，编码结构伊卡基因（icaABCD）的阻遏物。总之，我们得出结论，Spx履行的生长，一般的压力保护，和生物膜形成在S。金黄色。
In Bacillus subtilis, Spx was recently characterized as a novel type of global regulator whose activity is regulated by the redox status of the cells. In the present study, we demonstrate that inactivation of Spx in the important pathogen Staphylococcus aureus renders the cells hypersensitive to a wide range of stress conditions including high and low temperature, high osmolarity, and hydrogen peroxide. Moreover, growth was restricted under nonstress conditions. Two-dimensional gel electrophoresis revealed that the proteome of the spx mutant differs substantially from the proteome of wild-type cells, supporting the finding that Spx is also a global regulator in S. aureus. More specifically, we demonstrated that Spx is required for transcription of trxB, encoding thioredoxin reductase, under all growth conditions examined. As trxB is essential in S. aureus, we speculate that the severely reduced trxB transcription could account for some of the growth defects of the spx mutant. Inactivation of spx also enhanced biofilm formation. S. aureus biofillm formation is associated with the production of the polysaccharide intercellular adhesin encoded by the ica operon. Interestingly, our data indicate that the augmented capacity of the spx mutant to form biofilms is due to Spx modulating the expression of icaR, encoding a repressor of the structural ica genes (icaABCD). In summary, we conclude that Spx fulfills an important role for growth, general stress protection, and biofilm formation in S. aureus.