Control of the AcrAB multidrug efflux pump by quorum-sensing regulator SdiA

Mol Microbiol. 2002 Feb;43(3):677-85. doi: 10.1046/j.1365-2958.2002.02773.x.


SdiA is an Escherichia coli protein that regulates cell division in a cell density-dependent, or quorum-sensing, manner. We report that SdiA also controls multidrug resistance by positively regulating the multidrug resistance pump AcrAB. Overproduction of SdiA confers multidrug resistance and increased levels of AcrAB. Conversely, sdiA null mutants are hypersensitive to drugs and have decreased levels of AcrB protein. Our findings provide a link between quorum sensing and multidrug efflux. Combined with previously published reports, our data support a model in which a role of drug efflux pumps is to mediate cell-cell communication in response to cell density. Xenobiotics expelled by pumps may resemble the communication molecules that they normally efflux.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins / drug effects
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Carrier Proteins*
  • Drug Resistance, Multiple, Bacterial / physiology*
  • Escherichia coli / drug effects
  • Escherichia coli / physiology*
  • Escherichia coli Proteins*
  • Gene Expression Regulation, Bacterial
  • Lipoproteins / drug effects
  • Lipoproteins / genetics
  • Lipoproteins / metabolism*
  • Membrane Proteins / drug effects
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Membrane Transport Proteins
  • Multidrug Resistance-Associated Proteins
  • Mutation
  • Quinolones / pharmacology
  • Trans-Activators / drug effects
  • Trans-Activators / genetics
  • Trans-Activators / metabolism*


  • AcrA protein, E coli
  • AcrB protein, E coli
  • Bacterial Proteins
  • Carrier Proteins
  • Escherichia coli Proteins
  • Lipoproteins
  • Membrane Proteins
  • Membrane Transport Proteins
  • Multidrug Resistance-Associated Proteins
  • Quinolones
  • SdiA protein, bacteria
  • Trans-Activators
  • sdiA protein, E coli