Accessory gene regulator control of staphyloccoccal enterotoxin d gene expression.
Accessory gene regulator control of staphyloccoccal enterotoxin d gene expression.
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辅助基因调节器控制葡萄球菌肠毒素 d 基因表达。
DOI：
10.1128/jb.186.6.1793-1801.2004
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发表时间：
2004
影响因子：
3.2
通讯作者：
Stewart,GeorgeC
中科院分区：
文献类型：
--
作者：
Tseng,ChingWen;Zhang,Shuping;Stewart,GeorgeC
金黄色葡萄球菌的群体感应系统是辅助基因调节系统(AGR)，负责在生长指数后阶段增加某些外源蛋白基因的转录，减少某些细胞壁相关蛋白的转录。这一调节对毒力很重要，与AGR系统的丧失相关的毒力的降低就是明证。肠毒素D(Sed)决定簇被AGR系统上调。为了确定这些启动子区域内受AGR调控的顺式元件(S)，我们利用了不受AGR调控的启动子来创建杂交启动子。通过将序列与肠毒素A(SEA)启动子或THES相结合来创建杂交启动子。金黄色葡萄球菌乳胶操纵子启动子序列。结果表明，这些启动子的agr调控元件位于−35启动子元件内，位于启动子+1位点的Pribnow盒中。在这些启动子的这些位置，发现了一个直接重复的6个碱基序列。这种重复对整个启动子活性很重要，最大限度地调节启动子活性需要这两个重复元件。此外，研究发现，AGR对SED启动子活性的控制依赖于功能腐烂蛋白的存在。因此，指数后转录增加是AGR介导的Rot活性降低的结果，而不是AGR系统的直接影响。
The quorum-sensing system ofStaphylococcus aureus, the accessory gene regulator (Agr) system, is responsible for increased transcription of certain exoprotein genes and decreased transcription of certain cell wall-associated proteins during the postexponential phase of growth. This regulation is important for virulence, as evidenced by a reduction in virulence associated with a loss of the Agr system. The enterotoxin D (sed) determinant is upregulated by the Agr system. To define the Agr-regulatedciselement(s) within thesedpromoter region, we utilized promoters not regulated by Agr to create hybrid promoters. Hybrid promoters were created by usingsedsequences combined with the enterotoxin A (sea) promoter or theS. aureus lacoperon promoter sequences. The results obtained indicated that the Agr control element of thesedpromoter resides within the −35 promoter element and at the Pribnow box to the +1 site of the promoter. At these positions of thesedpromoter, a directly repeated 6-bp sequence was found. This repeat is important for overall promoter activity, and maximal regulation of the promoter activity requires both repeat elements. Furthermore, Agr control ofsedpromoter activity was found to be dependent upon the presence of a functional Rot protein. Therefore, the postexponential increase insedtranscription results from the Agr-mediated reduction in Rot activity rather than as a direct effect of the Agr system.