The PhoP/PhoQ System and Its Role in Serratia marcescens Pathogenesis
The PhoP/PhoQ System and Its Role in Serratia marcescens Pathogenesis
复制标题
DOI：
10.1128/jb.06820-11
复制
发表时间：
2012-06-01
影响因子：
3.2
通讯作者：
Garcia Vescovi, Eleonora
中科院分区：
文献类型：
--
作者：
Barchiesi, Julieta;Eugenia Castelli, Maria;Garcia Vescovi, Eleonora
粘质沙雷氏菌能够在非吞噬细胞内侵入、持续存在和繁殖，存在于非酸性、非降解性的自噬体样液泡中。在这项工作中，我们研究了 PhoP/PhoQ 系统的生理作用及其在控制粘质沙门氏菌关键毒力表型中的功能。我们已经证明，PhoP/PhoQ 系统参与该细菌适应稀缺环境 Mg2+、酸性 pH 和多粘菌素 B 的生长。我们还表明，这些环境条件构成了激活 PhoP/PhoQ 系统的信号。我们发现两个粘质沙门氏菌 mgtE 直向同源物呈现保守的 PhoP 结合基序，并证明 mgtE1 表达是 PhoP 依赖性的，增强了 PhoP 控制在镁稳态中的重要性。最后，我们证明 phoP 表达在细胞内被激活，并且 phoP 突变株在上皮细胞内存活有缺陷。我们已经证明沙雷氏菌 PhoP/PhoQ 系统参与防止递送至降解/酸性区室。
Serratia marcescens is able to invade, persist, and multiply inside nonphagocytic cells, residing in nonacidic, nondegradative, autophagosome-like vacuoles. In this work, we have examined the physiological role of the PhoP/PhoQ system and its function in the control of critical virulence phenotypes in S. marcescens. We have demonstrated the involvement of the PhoP/PhoQ system in the adaptation of this bacterium to growth on scarce environmental Mg2+, at acidic pH, and in the presence of polymyxin B. We have also shown that these environmental conditions constitute signals that activate the PhoP/PhoQ system. We have found that the two S. marcescens mgtE orthologs present a conserved PhoP-binding motif and demonstrated that mgtE1 expression is PhoP dependent, reinforcing the importance of PhoP control in magnesium homeostasis. Finally, we have demonstrated that phoP expression is activated intracellularly and that a phoP mutant strain is defective in survival inside epithelial cells. We have shown that the Serratia PhoP/PhoQ system is involved in prevention of the delivery to degradative/acidic compartments.