Enterococcus faecalis zinc-responsive proteins mediate bacterial defence against zinc overload, lysozyme and oxidative stress
Enterococcus faecalis zinc-responsive proteins mediate bacterial defence against zinc overload, lysozyme and oxidative stress
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DOI：
10.1099/mic.0.080341-0
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发表时间：
2014-12-01
期刊：
影响因子：
2.8
通讯作者：
Silva Lopes, Maria de Fatima
中科院分区：
文献类型：
--
作者：
Abrantes, Marta C.;Kok, Jan;Silva Lopes, Maria de Fatima
两个编码p型atp酶EF1400和推测的SapB蛋白EF0759的粪肠球菌基因先前被证明在高浓度锌的存在下强烈上调。在目前的工作中，我们发现在这些基因的启动子区域存在一个响应Zn2+的dna结合基序（zim）。我们进一步研究了这两种蛋白在锌稳态和宿主入侵中的作用。EF0759通过一种尚不清楚的机制促进巨噬细胞存活。EF1400，这里更名为ZntA(Ef)，是一种对锌具有特异性的atp酶，在处理几种宿主防御中起作用，即锌超载，氧化应激和溶菌酶；它为粪肠杆菌细胞提供了在巨噬细胞内存活的能力。由于这三种宿主防御机制在宿主的几个部位（即巨噬细胞内和唾液中）都很重要，因此这项工作表明ZntAEf构成了粪肠杆菌的关键防御机制，可能有助于这种细菌在其宿主内忍受生命的能力。
Two Enterococcus faecalis genes encoding the P-type ATPase EF1400 and the putative SapB protein EF0759 were previously shown to be strongly upregulated in the presence of high concentrations of zinc. In the present work, we showed that a Zn2+-responsive DNA-binding motif (zim) is present in the promoter regions of these genes. Both proteins were further studied with respect to their involvement in zinc homeostasis and invasion of the host. EF0759 contributed to intramacrophage survival by an as-yet unknown mechanism(s). EF1400, here renamed ZntA(Ef), is an ATPase with specificity for zinc and plays a role in dealing with several host defences, i.e. zinc overload, oxidative stress and lysozyme; it provides E. faecalis cells with the ability to survive inside macrophages. As these three host defence mechanisms are important at several sites in the host, i.e. inside macrophages and in saliva, this work suggested that ZntAEf constitutes a crucial E. faecalis defence mechanism that is likely to contribute to the ability of this bacterium to endure life inside its host.