Functional genetic analysis reveals a 2-Alkyl-4-quinolone signaling system in the human pathogen Burkholderia pseudomallei and related bacteria.
Pseudomonas aeruginosa synthesizes diverse 2-alkyl-4(1H)-quinolones (AHQs), including the signaling molecule 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS), via the pqsABCDE locus. By examining the genome databases, homologs of the pqs genes were identified in other bacteria. However, apart from P. aeruginosa, only Burkholderia pseudomallei and B. thailandensis contained a complete pqsA-E operon (termed hhqA-E). By introducing the B. pseudomallei hhqA and hhqE genes into P. aeruginosa pqsA and pqsE mutants, we show that they are functionally conserved and restore virulence factor and PQS production. B. pseudomallei, B. thailandensis, B. cenocepacia, and P. putida each produced 2-heptyl-4(1H)-quinolone (HHQ), but not PQS. Mutation of hhqA in B. pseudomallei resulted in the loss of AHQ production, altered colony morphology, and enhanced elastase production, which was reduced to parental levels by exogenous HHQ. These data reveal a role for AHQs in bacterial cell-to-cell communication beyond that seen in P. aeruginosa.
Diggle
Stephen P
SP
Institute of Infection, Immunity & Inflammation, Centre for Biomolecular Sciences, University Park, University of Nottingham, UK. steve.diggle@nottingham.ac.uk
Lumjiaktase
Putthapoom
P
Dipilato
Francesca
F
Winzer
Klaus
K
Kunakorn
Mongkol
M
Barrett
David A
DA
Chhabra
Siri Ram
SR
Cámara
Miguel
M
Williams
Paul
P
D016957:Burkholderia pseudomallei / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D005798:Genes, Bacterial; D013058:Mass Spectrometry; D010196:Pancreatic Elastase / Q000096:biosynthesis; D015363:Quinolones / Q000378:metabolism*; D015398:Signal Transduction; D013045:Species Specificity
D015363:Quinolones; D010196:Pancreatic Elastase