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A type VI secretion system regulated by OmpR in Y ersinia pseudotuberculosis functions to maintain intracellular pH homeostasis
Author(s) -
Zhang Weipeng,
Wang Yao,
Song Yunhong,
Wang Tietao,
Xu Shengjuan,
Peng Zhong,
Lin Xiaoli,
Zhang Lei,
Shen Xihui
Publication year - 2013
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.12005
Subject(s) - biology , secretion , operon , context (archaeology) , intracellular , bacteria , microbiology and biotechnology , type three secretion system , escherichia coli , gene , virulence , biochemistry , genetics , paleontology
Summary Type VI secretion systems ( T6SSs ) which widely distributed in G ram‐negative bacteria have been primarily studied in the context of cell interactions with eukaryotic hosts or other bacteria. We have recently identified a thermoregulated T6SS4 in the enteric pathogen Y ersinia pseudotuberculosis . Here we report that OmpR directly binds to the promoter of T6SS4 operon and regulates its expression. Further, we observed that the OmpR ‐regulated T6SS4 is essential for bacterial survival under acidic conditions and that its expression is induced by low pH . Moreover, we showed that T6SS4 plays a role in pumping H + out of the cell to maintain intracellular pH homeostasis. The acid tolerance phenotype of T6SS4 is dependent on the ATPase activity of ClpV4 , one of the components of T6SS4 . These results not only uncover a novel strategy utilized by Y . pseudotuberculosis for acid resistance, but also reveal that T6SS , a bacteria secretion system known to be functional in protein transportation has an unexpected function in H + extrusion under acid conditions.