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Updated: Apr 19, 2026
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Identifying the Binding Proteins of Small Ligands with the Differential Radial Capillary Action of Ligand Assay DRaCALA
Published on: March 19, 2021
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Dialkylresorcinols as bacterial signaling molecules
Sophie Brameyer1, Darko Kresovic2, Helge B Bode3
1Ludwig-Maximilians-Universität München, Biozentrum, Bereich Mikrobiologie, 82152 Martinsried/München, Germany;
Summary
Bacteria use quorum sensing for communication. This study reveals Photorhabdus asymbiotica uses novel dialkylresorcinols (DARs) and cyclohexanediones (CHDs) instead of acylated homoserine lactones (AHLs) for signaling, impacting virulence.
Area of Science:
- Microbiology
- Bacterial Communication
- Molecular Biology
Background:
- Bacteria communicate using quorum sensing (QS) systems, primarily with acylated homoserine lactones (AHLs).
- Many bacteria possess LuxR receptors but lack AHL synthases, known as LuxR solos, with their signaling molecules largely unknown.
- The signaling molecules sensed by LuxR solos represent a gap in understanding bacterial cell-cell communication.
Purpose of the Study:
- To identify the novel cell-cell communication system in the pathogen Photorhabdus asymbiotica.
- To characterize the signaling molecules and their synthesis pathway in P. asymbiotica.
- To investigate the role of this novel QS system in bacterial virulence.
Main Methods:
- Identification of a LuxR homolog (PauR) in Photorhabdus asymbiotica.
- Characterization of signaling molecules as dialkylresorcinols (DARs) and cyclohexanediones (CHDs).
- Analysis of the DarABC synthesis pathway.
- HPLC/MS analysis of over 90 Photorhabdus strains.
- Genomic analysis of potential DAR producers.
Main Results:
- Photorhabdus asymbiotica utilizes PauR to sense DARs and CHDs, not AHLs.
- The DarABC pathway synthesizes these novel signaling molecules.
- The identified QS system is crucial for the virulence of P. asymbiotica.
- DARs and CHDs are specific to the human pathogen P. asymbiotica, with potential production in 116 other bacterial species.
Conclusions:
- Photorhabdus asymbiotica employs a novel quorum sensing system using DARs and CHDs.
- DARs and CHDs represent a new class of widespread bacterial signaling molecules.
- Bacterial cell-cell communication extends beyond known AHL-based systems, with implications for understanding pathogen virulence.
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