ςB Activity in Staphylococcus aureus Is Controlled by RsbU and an Additional Factor(s) during Bacterial Growth
ςB Activity in Staphylococcus aureus Is Controlled by RsbU and an Additional Factor(s) during Bacterial Growth
复制标题
金黄色葡萄球菌中的 B 活性受 RsbU 和细菌生长过程中的附加因素控制
作者：
M. Palma;A. Cheung
为了研究sigB操纵子基因rsbU和rsbV在金黄色葡萄球菌中对sigB B活性的影响，在一株rsbU+菌株（FDA 486）中缺失了两个基因rsbU和rsbV。在构建的突变体中，分析了两个依赖于β-淀粉样蛋白B的启动子（sigB和sarA P3转录物）的β-淀粉样蛋白B蛋白水平和转录。sigB操纵子内第一个基因（rsbU）的缺失仅导致β-淀粉样蛋白活性的部分降低。第二个基因（rsbV）的缺失导致了更显着的减少，在rsbU的缺失相比，RsbV的B蛋白水平和其活性，从而表明，RsbV可以激活独立的RsbU。在亲本菌株中，rsbV上游起始的依赖于p3 B的转录物比源自thersbU启动子的依赖于p3 A的转录物高28倍。与野生型中的转录物相比，在thersbU突变体中的cDNAB依赖性转录物的水平降低了50%，在rsbV突变体中降低了90%。S.金黄色葡萄球菌菌落，一种依赖于ALB的表型，在thersbU和rsbV突变体中部分减少，而α-溶血素增加。此外，亲本菌株的sarA P3启动子活性被诱导到响应于pH 5.5比rsbU或rsbV突变体的更高的水平，表明RsbU是对酸胁迫的响应的主要激活剂。使用四环素诱导的系统来调节RsbW的表达，我们逐步抑制色素的产生，大概是通过减少游离β B水平。结果表明，S.金黄色葡萄球菌导致了不同水平的p53 B蛋白表达和不同的p53 B活性。虽然RsbV可以独立于RsbU激活β B，但在酸胁迫期间RsbU仍然是β B的主要激活剂。
ABSTRACT Two genes of the sigB operon,rsbU and rsbV, were deleted in anrsbU+ strain (FDA486) to evaluate the contribution of these two genes to ςB activity inStaphylococcus aureus. The ςB protein level and the transcription of two ςB-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 ςβ activity. A deletion of the second gene (rsbV) resulted in a more dramatic reduction in the ςB 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 ςB-dependent transcript initiated upstream ofrsbV was 28-fold higher than the ςA-dependent transcript originating from thersbU promoter. The level of the ςB-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 ςB-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 ςB 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 ςB level. Collectively, our data indicated that RsbU and RsbV in S. aureus contributed to different levels of ςB protein expression and varying ςB activities. Although RsbV can activate ςB independent of RsbU, RsbU remains the major activator of ςB during acid stress.
DOI：
10.1073/pnas.90.6.2330
发表时间：
1993-03-15
影响因子：
11.1
作者：
BENSON, AK;HALDENWANG, WG
通讯作者：
HALDENWANG, WG
DOI：
10.1073/pnas.91.16.7573
发表时间：
1994-08-02
影响因子：
11.1
作者：
LONETTO, MA;BROWN, KL;BUTTNER, MJ
通讯作者：
BUTTNER, MJ
影响因子：
2.9
作者：
BLAKE, MS;JOHNSTON, KH;GOTSCHLICH, EC
通讯作者：
GOTSCHLICH, EC