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首页> 外文期刊>Infection and immunity >?B Activity in Staphylococcus aureus Is Controlled by RsbU and an Additional Factor(s) during Bacterial Growth
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?B Activity in Staphylococcus aureus Is Controlled by RsbU and an Additional Factor(s) during Bacterial Growth

机译：金黄色葡萄球菌中的？B活性受RsbU和细菌生长过程中其他因素的控制。

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Two genes of the sigB operon,rsbU and rsbV, were deleted in anrsbU + strain (FDA486) to evaluate the contribution of these two genes to ?B activity inStaphylococcus aureus. The ?B protein level and the transcription of two ?B-dependent promoters (sigB and sarA P3 transcripts) were analyzed in the constructed mutants. A deletion of the first gene (rsbU) within the sigB operon led only to a partial reduction in ?β activity. A deletion of the second gene (rsbV) resulted in a more dramatic reduction in the ?B protein level and its activity than did the deletion of rsbU, thus indicating that RsbV can be activated independent of RsbU. In the parental strain, the ?B-dependent transcript initiated upstream ofrsbV was 28-fold higher than the ?A-dependent transcript originating from thersbU promoter. The level of the ?B-dependent transcript decreased up to 50% in thersbU mutant and up to 90% in the rsbVmutant compared with the transcript in the wild type. The yellow pigment of S. aureus colonies, a ?B-dependent phenotype, was partially reduced in thersbU and rsbV mutants, whereas alpha-hemolysin was increased. Additionally, the sarA P3 promoter activity of the parental strain was induced to a higher level in response to pH 5.5 than was that of the rsbU orrsbV mutant, indicating that RsbU is the major activator of the ?B response to acid stress. Using a tetracycline-inducible system to modulate the expression of RsbW, we progressively repressed pigment production, presumably by reducing the free ?B level. Collectively, our data indicated that RsbU and RsbV in S. aureus contributed to different levels of ?B protein expression and varying ?B activities. Although RsbV can activate ?B independent of RsbU, RsbU remains the major activator of ?B during acid stress.
机译： sigB 操纵子的两个基因， rsbU 和 rsbV ，被删除在一个 rsbU + 菌株（FDA486），以评估这两个基因对金黄色葡萄球菌β B 活性的贡献。β B 蛋白水平和在构建的突变体中分析了两个依赖于β B 的启动子（ sigB 和 sarA P3转录物）的转录。在 sigB 操纵子中第一个基因（ rsbU ）的缺失仅导致ββ活性的部分降低。与删除 rsbU 相比，删除第二个基因（ rsbV ）导致？ B 蛋白质水平及其活性的降低更为明显。 >，因此表明可以独立于RsbU激活RsbV。在亲本菌株中，起始于 rsbV 上游的依赖于 sup> B 的转录本比源自起源的依赖于β A 的转录本高28倍。 rsbU 启动子。与 rsbU 突变体相比，？ B 依赖性转录本水平降低了50％，而在 rsbV 突变体中降低了90％。野生型的笔录。 S 的黄色颜料。在 rsbU 和 rsbV 突变体中， aureus 菌落（一种依赖于 sup sup>的表型）被部分还原，而alpha -溶血素增加。此外，与 rsbU 或 rsbV 相比，pH 5.5对亲本菌株的 sarA P3启动子活性有更高的诱导作用。 >突变体，表明RsbU是？ B 对酸胁迫的响应的主要激活剂。使用四环素诱导系统调节RsbW的表达，我们逐渐降低了色素的产生，大概是通过降低游离的 B 水平。总体而言，我们的数据表明 S 中的RsbU和RsbV。 金黄色葡萄球菌导致不同水平的α B 蛋白表达和不同的α B 活性。尽管RsbV可以独立于RsbU激活α B ，但在酸性胁迫下，RsbU仍是α B 的主要激活剂。

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