Krypotou E, Scortti M, Grundström C, Oelker M, Luisi BF, Sauer-Eriksson AE, Vázquez-Boland J. Control of Bacterial Virulence through the Peptide Signature of the Habitat.
Cell Rep 2020;
26:1815-1827.e5. [PMID:
30759392 PMCID:
PMC6389498 DOI:
10.1016/j.celrep.2019.01.073]
[Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/09/2018] [Accepted: 01/17/2019] [Indexed: 12/20/2022] Open
Abstract
To optimize fitness, pathogens selectively activate their virulence program upon host entry. Here, we report that the facultative intracellular bacterium Listeria monocytogenes exploits exogenous oligopeptides, a ubiquitous organic N source, to sense the environment and control the activity of its virulence transcriptional activator, PrfA. Using a genetic screen in adsorbent-treated (PrfA-inducing) medium, we found that PrfA is functionally regulated by the balance between activating and inhibitory nutritional peptides scavenged via the Opp transport system. Activating peptides provide essential cysteine precursor for the PrfA-inducing cofactor glutathione (GSH). Non-cysteine-containing peptides cause promiscuous PrfA inhibition. Biophysical and co-crystallization studies reveal that peptides inhibit PrfA through steric blockade of the GSH binding site, a regulation mechanism directly linking bacterial virulence and metabolism. L. monocytogenes mutant analysis in macrophages and our functional data support a model in which changes in the balance of antagonistic Opp-imported oligopeptides promote PrfA induction intracellularly and PrfA repression outside the host.
Listeria PrfA virulence regulation is controlled by antagonistic nutritional peptides
Opp-imported peptides regulate PrfA upstream of the activating cofactor GSH
PrfA is activated by peptides that provide essential cysteine for GSH biosynthesis
Blockade of PrfA’s GSH binding site by peptides inhibits virulence gene activation
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