title: Regulation of membrane permeability by a two-component regulatory system in Pseudomonas aeruginosa.
abstract: Membrane impermeability is the major contributing factor to multidrug resistance in clinical isolates of Pseudomonas aeruginosa. By using laboratory strain PAK, a spontaneous P. aeruginosa mutant (mutant PAK1-3) whose membrane had reduced permeability and which displayed increased levels of resistance to various antibiotics, especially aminoglycosides, was isolated. By complementation of the mutant with a genomic clone library derived from wild-type strain PAK, a novel two-component regulatory system (PprA and PprB) was identified and was found to be able to increase the permeability of the bacterial membrane and render PAK1-3 sensitive to antibiotics. Furthermore, specific phosphorylation of the response regulator (PprB) by histidine kinase (PprA) was observed in vitro, demonstrating that they are cognate two-component regulatory genes. Introduction of a plasmid expressing the pprB gene into randomly chosen clinical isolates (n = 17) resulted in increased sensitivity to aminoglycosides in the majority of isolates (n = 13) tested. This is the first demonstration that P. aeruginosa membrane permeability can be regulated, providing an important clue in the understanding of the mechanism of membrane impermeability-mediated multidrug resistance in P. aeruginosa.
authors.affiliation: Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida 32610, USA.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Wang
authors.forename: Unhwan
authors.initials: U
authors.lastname: Ha
authors.forename: Lin
authors.initials: L
authors.lastname: Zeng
authors.forename: Shouguang
authors.initials: S
authors.lastname: Jin
mesh_terms: D002463:Cell Membrane Permeability / Q000235:genetics* / Q000502:physiology; D018432:Drug Resistance, Multiple / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D011550:Pseudomonas aeruginosa / Q000235:genetics*