title: Dialkylresorcinols as bacterial signaling molecules.
abstract: It is well recognized that bacteria communicate via small diffusible molecules, a process termed quorum sensing. The best understood quorum sensing systems are those that use acylated homoserine lactones (AHLs) for communication. The prototype of those systems consists of a LuxI-like AHL synthase and a cognate LuxR receptor that detects the signal. However, many proteobacteria possess LuxR receptors, yet lack any LuxI-type synthase, and thus these receptors are referred to as LuxR orphans or solos. In addition to the well-known AHLs, little is known about the signaling molecules that are sensed by LuxR solos. Here, we describe a novel cell-cell communication system in the insect and human pathogen Photorhabdus asymbiotica. We identified the LuxR homolog PauR to sense dialkylresorcinols (DARs) and cyclohexanediones (CHDs) instead of AHLs as signals. The DarABC synthesis pathway produces the molecules, and the entire system emerged as important for virulence. Moreover, we have analyzed more than 90 different Photorhabdus strains by HPLC/MS and showed that these DARs and CHDs are specific to the human pathogen P. asymbiotica. On the basis of genomic evidence, 116 other bacterial species are putative DAR producers, among them many human pathogens. Therefore, we discuss the possibility of DARs as novel and widespread bacterial signaling molecules and show that bacterial cell-cell communication goes far beyond AHL signaling in nature.
authors.affiliation: Ludwig-Maximilians-Universität München, Biozentrum, Bereich Mikrobiologie, 82152 Martinsried/München, Germany;
authors.forename: Sophie
authors.initials: S
authors.lastname: Brameyer
authors.affiliation: Goethe-Universität Frankfurt, Merck Stiftungsprofessur für Molekulare Biotechnologie, Fachbereich Biowissenschaften, 60438 Frankfurt am Main, Germany; and.
authors.forename: Darko
authors.initials: D
authors.lastname: Kresovic
authors.affiliation: Goethe-Universität Frankfurt, Merck Stiftungsprofessur für Molekulare Biotechnologie, Fachbereich Biowissenschaften, 60438 Frankfurt am Main, Germany; and Buchmann Institute for Molecular Life Sciences, Goethe Universität Frankfurt, 60438 Frankfurt am Main, Germany h.bode@bio.uni-frankfurt.de heermann@lmu.de.
authors.forename: Helge B
authors.initials: HB
authors.lastname: Bode
authors.affiliation: Ludwig-Maximilians-Universität München, Biozentrum, Bereich Mikrobiologie, 82152 Martinsried/München, Germany; h.bode@bio.uni-frankfurt.de heermann@lmu.de.
authors.forename: Ralf
authors.initials: R
authors.lastname: Heermann
mesh_terms: D054742:Acyl-Butyrolactones / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D017124:Conserved Sequence; D003512:Cyclohexanones / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009876:Operon; D020637:Photorhabdus / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D011487:Protein Conformation; D053038:Quorum Sensing / Q000235:genetics / Q000502:physiology*; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012118:Resorcinols / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D054742:Acyl-Butyrolactones; D001426:Bacterial Proteins; D003512:Cyclohexanones; D004269:DNA, Bacterial; D012097:Repressor Proteins; D012118:Resorcinols; D015534:Trans-Activators; C064778:LuxR autoinducer binding proteins
keywords: LuxR solos; Photorhabdus; cell–cell communication; pathogenic bacteria; quorum sensing