The σB-Dependent yabJ-spoVG Operon Is Involved in the Regulation of Extracellular Nuclease, Lipase, and Protease Expression in Staphylococcus aureus
The σB-Dependent yabJ-spoVG Operon Is Involved in the Regulation of Extracellular Nuclease, Lipase, and Protease Expression in Staphylococcus aureus
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DOI：
10.1128/jb.05362-11
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发表时间：
2011-09-01
影响因子：
3.2
通讯作者：
Berger-Baechi, Brigitte
中科院分区：
文献类型：
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作者：
Schulthess, Bettina;Bloes, Dominik A.;Berger-Baechi, Brigitte
金黄色葡萄球菌的选择性σ因子σ（B）参与协调一般应激反应、毒力决定簇的表达和抗生素耐药性水平的调节。它通过识别保守的sigma（B）启动子序列直接或通过sigma（B）依赖性元件间接控制大的调节子。sigma（B）控制的yabJ-spoVG操纵子编码两个这样的推定下游元件。我们在这里报告S.金黄色葡萄球菌纽曼，显示yabJ-spoVG操纵子的失活主要对主要编码毒力因子的小亚调节子具有抑制作用，所述毒力因子包括核酸酶（nuc）、蛋白酶（splE）和脂肪酶（lip）。因此，细胞外核酸酶，蛋白酶，和脂肪酶的活动减少在Delta yabJ-spoVG突变体。SpoVG的反式互补足以恢复它们降低的表型表达和由于yabJ-spoVG缺失而降低的转录。然而，它没有恢复由sigma（B）失活触发的变化，表明两种调节子仅部分重叠，尽管yabJ-spoVG表达依赖于sigma（B）。因此，sigma（B）可能控制影响许多水解酶表达的其他SpoVG非依赖性因素。另一方面，SpoVG似乎通过拮抗sigma（B）效应来微调毒力因子子集的sigma（B）依赖性调节。
The alternative sigma factor sigma(B) of Staphylococcus aureus is involved in the coordination of the general stress response, expression of virulence determinants, and modulation of antibiotic resistance levels. It controls a large regulon, either directly by recognizing conserved sigma(B) promoter sequences or indirectly via sigma(B)-dependent elements. The sigma(B)-controlled yabJ-spoVG operon encodes two such putative downstream elements. We report here transcriptome analysis in S. aureus Newman, showing that inactivation of the yabJ-spoVG operon had primarily a repressing effect on a small subregulon encoding mainly virulence factors, including a nuclease (nuc), a protease (splE) and a lipase (lip). As a consequence, extracellular nuclease, protease, and lipase activities were reduced in a Delta yabJ-spoVG mutant. trans-complementation by SpoVG was sufficient to restore their reduced phenotypic expression and lowered transcription due to the yabJ-spoVG deletion. It did not restore, however, the changes triggered by sigma(B) inactivation, indicating that both regulons only partially overlap, despite the sigma(B) dependency of the yabJ-spoVG expression. Thus, sigma(B) is likely to control additional, SpoVG-independent factors affecting the expression of numerous hydrolytic enzymes. SpoVG, on the other hand, seems to fine-tune the sigma(B)-dependent regulation of a subset of virulence factors by antagonizing the sigma(B) effect.