The YvqE two-component system controls biofilm formation and acid production in Streptococcus pyogenes
The YvqE two-component system controls biofilm formation and acid production in Streptococcus pyogenes
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DOI：
10.1111/apm.12538
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发表时间：
2016-07-01
期刊：
影响因子：
2.8
通讯作者：
Hasegawa, Tadao
中科院分区：
文献类型：
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作者：
Isaka, Masanori;Tatsuno, Ichiro;Hasegawa, Tadao
在化脓性链球菌中，参与决定毒力的蛋白质由独立的反应调节器和双组分调节系统控制。以前的研究报道，与亲本菌株相比，yvqE传感器敲除菌株的生长显著减慢，毒力较低。为了确定YvqE的功能，我们对YvqE突变体进行了生物被膜分析和pH测定，并对YvqE进行了定点突变。YvqE缺失突变体的产酸速率较慢，表明YvqE调控糖发酵产酸。突变株YvqE中的Asp(26)残基被Asn取代，影响生物膜的形成，表明该氨基酸感知发酵糖代谢产生的氢离子。YvqE收到的信号直接或间接地诱导了菌毛的表达。本研究表明，在低环境pH条件下，化脓性链球菌生物膜的形成是由YvqE介导的，提示环境酸化对菌毛表达的调控可能直接受YvqE的调控。
In Streptococcus pyogenes, proteins involved in determining virulence are controlled by stand-alone response regulators and by two-component regulatory systems. Previous studies reported that, compared to the parental strain, the yvqE sensor knockout strain showed significantly reduced growth and lower virulence. To determine the function of YvqE, we performed biofilm analysis and pH assays on yvqE mutants, and site-directed mutagenesis of YvqE. The yvqE deletion mutant showed a slower acid production rate, indicating that YvqE regulates acid production from sugar fermentation. The mutant strain, in which the Asp(26) residue in YvqE was replaced with Asn, affected biofilm formation, suggesting that this amino acid senses hydrogen ions produced by fermentative sugar metabolism. Signals received by YvqE were directly or indirectly responsible for inducing pilus expression. This study shows that at low environmental pH, biofilm formation in S. pyogenes is mediated by YvqE and suggests that regulation of pilus expression by environmental acidification could be directly under the control of YvqE.