SCIENCE@home

The H-NS homologues MvaT and MvaU repress CRISPR-Cas in Pseudomonas aeruginosa.

K. Koonce,Jesper Juel Mauritzen,Ida Friberg Hitz,Emil Funk Vangsgaard,Elizabeth H M Putz,Anne Sofie Wajn,Frederik Hagelund Leth,N. M. Høyland-Kroghsbo

Published 2025 in Philosophical transactions of the Royal Society of London. Series B, Biological sciences

ABSTRACT

CRISPR-Cas is an adaptive immune system of bacteria and archaea that protects against foreign genetic elements. In Escherichia coli and Salmonella, CRISPR-Cas is inhibited by the conserved global repressor the histone-like nucleoid structuring protein (H-NS), which blocks the expression of AT-rich horizontally acquired genes. While the opportunistic pathogen Pseudomonas aeruginosa harbours two partially redundant H-NS homologues, MvaT and MvaU, their role in CRISPR-Cas regulation in this bacterium remains unexplored. Here, we demonstrate that in the absence of both MvaT and MvaU, CRISPR-Cas activity increases more than tenfold, as measured by a reduction in the transformation efficiency of a CRISPR-targeted plasmid. Importantly, we find that in the absence of MvaT and MvaU, Cas proteins are already produced at low cell density prior to the onset of quorum sensing-mediated activation of CRISPR-Cas, which occurs at high cell density. Moreover, the ∆mvaT ∆mvaU mutant has a significantly reduced growth rate, known to independently increase CRISPR-Cas activity. In addition to regulating CRISPR-Cas, the absence of MvaT and MvaU affects phage-host interactions, including enhancing the adsorption of the LPS-binding phage JBD44, highlighting their broader role in coordinating bacterial defence mechanisms.This article is part of the discussion meeting issue 'The ecology and evolution of bacterial immune systems'.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-74 of 74 references · Page 1 of 1

CITED BY