Phosphorylation residue T175 in RsbR protein is required for efficient induction of sigma B factor and survival of Listeria monocytogenes under acidic stress.

Ke HE; Yong-ping Xin; Ying Shan; Xian Zhang; Hou-hui Song; Wei-huan Fang

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Phosphorylation residue T175 in RsbR protein is required for efficient induction of sigma B factor and survival of Listeria monocytogenes under acidic stress.

Author: Ke HE ¹ ; Yong-Ping XIN ² ; Ying SHAN ² ; Xian ZHANG ¹ ; Hou-Hui SONG ¹ ; Wei-Huan FANG ¹
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1. College of Animal Science and Technology, Zhejiang A&F University, Lin'an 311300, China.
2. Zhejiang University Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China.
Publication Type:Journal Article
Keywords: Listeria monocytogenes; RsbR; Sigma B (Sig B) factor; Phosphorylation
MeSH: Alanine/genetics*; Bacillus subtilis; Bacterial Proteins/metabolism*; Binding Sites; Gene Deletion; Gene Expression Regulation, Bacterial; Genetic Complementation Test; Homeostasis; Hydrogen-Ion Concentration; Listeria monocytogenes/metabolism*; Listeriosis/microbiology*; Mutation; Phenotype; Phosphoproteins/metabolism*; Phosphorylation; Sigma Factor/metabolism*; Stress, Physiological
From: Journal of Zhejiang University. Science. B 2019;20(8):660-669
CountryChina
Language:English
Abstract: Listeria monocytogenes is an important zoonotic foodborne pathogen that can tolerate a number of environmental stresses. RsbR, an upstream regulator of the sigma B (SigB) factor, is thought to sense environmental challenges and trigger the SigB pathway. In Bacillus subtilis, two phosphorylation sites in RsbR are involved in activating the SigB pathway and a feedback mechanism, respectively. In this study, the role of RsbR in L. monocytogenes under mild and severe stresses was investigated. Strains with genetic deletion (ΔrsbR), complementation (C-ΔrsbR), and phosphorylation site mutations in the rsbR (RsbR-T175A, RsbR-T209A, and RsbR-T175A-T209A) were constructed to evaluate the roles of these RsbR sequences in listerial growth and survival. SigB was examined at the transcriptional and translational levels. Deletion of rsbR reduced listerial growxth and survival in response to acidic stress. Substitution of the phosphorylation residue RsbR-T175A disabled RsbR complementation, while RsbR-T209A significantly upregulated SigB expression and listerial survival. Our results provide clear evidence that two phosphorylation sites of RsbR are functional in L. monocytogenes under acidic conditions, similar to the situation in B. subtilis.