Impact of the accessory gene regulatory system (Agr) on extracellular proteins, codY expression and amino acid metabolism in Staphylococcus epidermidis
Impact of the accessory gene regulatory system (Agr) on extracellular proteins, codY expression and amino acid metabolism in Staphylococcus epidermidis
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DOI：
10.1002/pmic.200500732
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发表时间：
2006-06-01
期刊：
影响因子：
3.4
通讯作者：
Ziebuhr, Wilma
中科院分区：
文献类型：
--
作者：
Batzilla, Christoph F.;Rachid, Shwan;Ziebuhr, Wilma
群体感应系统 Agr 是葡萄球菌基因表达复杂调控网络的一部分。本研究通过蛋白质组和转录组分析展示了 agr 突变对生物膜形成表皮葡萄球菌分离株的影响。 agr 突变体表现出胞外蛋白含量显着降低：其中包括 SspA、AtlE、GehD 和苯酚可溶性调节蛋白 PSM1/2。细胞质蛋白质组分析和表达谱表明，agr 失活导致代谢和毒力调节发生强烈改变。最引人注目的是，CodY（毒力和稳定期基因表达的全局调节因子）的表达在 agr 突变体中降低。在这方面，发现枯草芽孢杆菌和乳酸乳球菌中已知受 CodY 控制的同源基因在表皮葡萄球菌 agr 突变体中上调。综合数据显示，野生型和 agr 突变体在氨基酸生物合成和寡肽转运、碳水化合物利用以及 GMP 和 IMP 相互转化方面存在差异。由于表皮葡萄球菌 agr 突变体的不同生理特性（通常是自发发生的），可能能够在人类宿主中定植替代生态位，因此在适应不断变化的环境条件方面可能具有优势。
The quorum-sensing system Agr is part of a complex regulatory network of gene expression in staphylococci. This study presents the effect of an agr mutation on a biofilm-forming Staphylococcus epidermidis isolate by employing proteome and transcriptome analysis. The agr mutant exhibited a significantly lowered amount of extracellular proteins: amongst others SspA, AtlE, GehD and the phenol soluble modulins PSM1/2. Cytoplasmic proteome analysis and expression profiling indicated that the agr inactivation led to a strongly altered regulation of metabolism and virulence. Most strikingly, expression of CodY, a global regulator of virulence and stationary phase gene expression, was decreased in the agr mutant. In this respect, homologous genes known to be controlled by CodY in Bacillus subtilis and Lactococcus lactis were found to be upregulated in the S. epidermidis agr mutant. The combined data show that wild-type and agr mutant differ with respect to amino acid biosynthesis and oligopeptide transport, carbohydrate utilization, as well as GMP and IMP interconversion. Due to the varying physiological properties S. epidermidis agr mutants, which often occur spontaneously, might be capable of colonizing alternative ecological niches in the human host and could, therefore, have an advantage in adapting to changing environmental conditions.