Membrane vesicles traffic signals and facilitate group activities in a prokaryote

Nature. 2005 Sep 15;437(7057):422-5. doi: 10.1038/nature03925.


Many bacteria use extracellular signals to communicate and coordinate social activities, a process referred to as quorum sensing. Many quorum signals have significant hydrophobic character, and how these signals are trafficked between bacteria within a population is not understood. Here we show that the opportunistic human pathogen Pseudomonas aeruginosa packages the signalling molecule 2-heptyl-3-hydroxy-4-quinolone (pseudomonas quinolone signal; PQS) into membrane vesicles that serve to traffic this molecule within a population. Removal of these vesicles from the bacterial population halts cell-cell communication and inhibits PQS-controlled group behaviour. We also show that PQS actively mediates its own packaging and the packaging of other antimicrobial quinolines produced by P. aeruginosa into vesicles. These findings illustrate that a prokaryote possesses a signal trafficking system with features common to those used by higher organisms and outlines a novel mechanism for delivery of a signal critical for coordinating group behaviour in P. aeruginosa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Transport
  • Gene Expression Regulation, Bacterial / drug effects
  • Pseudomonas aeruginosa / cytology*
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / genetics
  • Pseudomonas aeruginosa / metabolism*
  • Quinolones / analysis
  • Quinolones / chemistry
  • Quinolones / metabolism*
  • Quinolones / pharmacology
  • Secretory Vesicles / metabolism*
  • Signal Transduction / drug effects


  • 2-heptyl-3-hydroxy-4-quinolone
  • Quinolones