The sae locus of Staphylococcus aureus controls exoprotein synthesis at the transcriptional level
The sae locus of Staphylococcus aureus controls exoprotein synthesis at the transcriptional level
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DOI：
10.1007/s002030050469
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发表时间：
1997-07-01
影响因子：
2.8
通讯作者：
Nagel, R
中科院分区：
文献类型：
--
作者：
Giraudo, AT;Cheung, AL;Nagel, R
Agr和sar是金黄色葡萄球菌的已知调节基因座，其控制几种细胞外和细胞壁相关蛋白的产生。在S.金黄色葡萄球菌，命名为SAE，其导致α-和β-溶血素和凝固酶水平的急剧降低和蛋白A水平的轻微降低。在sae：：Tn 551突变体中编码这些外蛋白的基因表达的研究（在本工作中通过北方印迹分析进行）表明，α-和β-溶血素（hla和hlb）和凝固酶（coa）的基因不转录，蛋白A（spa）的基因转录水平有所降低。这些结果表明sae基因座在转录水平上调控这些外蛋白基因。北方印迹分析也表明sae突变不影响agr或sar调控位点的表达。sae：：Tn 551 agr：：tetM双突变体的表型特征为产生降低或无效水平的α-、β-和δ-溶血素、凝固酶和高水平的蛋白A。北方印迹分析表明，在这项工作中进行的双突变体的hla，hlb，hld和coa基因不转录，而spa是在高水平转录。coa在sae agr突变体中不表达，而在sae亲本菌株中，spa以agr亲本菌株特有的高水平表达，这一事实表明sae和agr在控制几种外蛋白基因的表达中以复杂的方式相互作用。
Agr and sar are known regulatory loci of Staphylococcus aureus that control the production of several extracellular and cell-wail-associated proteins. A pleiotropic insertional mutation in S. aureus, designated sae, that leads to the production of drastically diminished levels of alpha- and beta-hemolysins and coagulase and slightly reduced levels of protein A has been described. The study of the expression of the genes coding for these exoproteins in the sae::Tn551 mutant (carried out in this work by Northern blot analyses) revealed that the genes for alpha- and beta-hemolysins (hla and hlb) and coagulase (coa) are not transcribed and that the gene for protein A (spa) is transcribed at a somewhat reduced level. These results indicate that the sae locus regulates these exoprotein genes at the transcriptional level. Northern blot analyses also show that the sae mutation does not affect the expression of agr or sar regulatory loci. An sae::Tn551 agr::tetM double mutant has been phenotypically characterized as producing reduced or null levels of alpha-, beta-, and delta-hemolysins, coagulase, and high levels of protein A. Northern blot analyses carried out in this work with the double mutant revealed that hla, hlb, hld, and coa genes are not transcribed, while spa is transcribed at high levels. The fact that coa is not expressed in the sae agr mutant, as in the sae parental strain, while spa is expressed at the high levels characteristic of the agr parental strain, suggests that sae and agr interact in a complex way in the control of the expression of the genes of several exoproteins.