Tatsuno Ichiro, Isaka Masanori, Okada Ryo, Zhang Yan, Hasegawa Tadao
Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8601, Japan.
BMC Res Notes. 2014 Mar 28;7:189. doi: 10.1186/1756-0500-7-189.
The production of virulence proteins depends on environmental factors, and two-component regulatory systems are involved in sensing these factors. We previously established knockout strains in all suspected two-component regulatory sensor proteins of the emm1 clinical strain of S. pyogenes and examined their relevance to acid stimuli in a natural atmosphere. In the present study, their relevance to acid stimuli was re-examined in an atmosphere containing 5% CO2.
The spy1236 (which is identical to ciaHpy) sensor knockout strain showed significant growth reduction compared with the parental strain in broth at pH 6.0, suggesting that the Spy1236 (CiaHpy) two-component sensor protein is involved in acid response of S. pyogenes. CiaH is also conserved in Streptococcus pneumoniae, and it has been reported that deletion of the gene for its cognate response regulator (ciaRpn) made the pneumococcal strains more sensitive to oxidative stress. In this report, we show that the spy1236 knockout mutant of S. pyogenes is more sensitive to oxidative stress than the parental strain.
These results suggest that the two-component sensor protein CiaH is involved in stress responses in S. pyogenes.
毒力蛋白的产生取决于环境因素，双组分调节系统参与感知这些因素。我们之前构建了化脓性链球菌emm1临床菌株所有疑似双组分调节传感器蛋白的敲除菌株，并在自然大气环境中研究了它们与酸刺激的相关性。在本研究中，我们在含5%二氧化碳的大气环境中重新研究了它们与酸刺激的相关性。
spy1236（与ciaHpy相同）传感器敲除菌株在pH 6.0的肉汤中与亲本菌株相比生长显著降低，这表明Spy1236（CiaHpy）双组分传感器蛋白参与了化脓性链球菌的酸反应。CiaH在肺炎链球菌中也保守，并且有报道称其同源应答调节因子（ciaRpn）的基因缺失使肺炎球菌菌株对氧化应激更敏感。在本报告中，我们表明化脓性链球菌的spy1236敲除突变体比亲本菌株对氧化应激更敏感。
这些结果表明双组分传感器蛋白CiaH参与了化脓性链球菌的应激反应。
