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

In this study, the role of RsbR inL. monocytogenes under mild and severe stresses was investigated. Strains with genetic deletion ( ΔrsbR), complementation (C-ΔrsbR), and phosphorylation site mutations in thersbR (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 ofrsbR 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 inL. monocytogenes under acidic conditions, similar to the situation inB. subtilis.
Source: Journal of Zhejiang University. Science. B. - Category: Universities & Medical Training Source Type: research