title: A novel role for protein-tyrosine kinase Etk from Escherichia coli K-12 related to polymyxin resistance.
abstract: The role of protein-tyrosine kinases in bacterial polymyxin resistance was assessed by both genetic and biochemical approaches. Each of the two genes, wzc and etk, encoding protein-tyrosine kinases in Escherichia coli, was knocked out by using the PCR-based method of one-step inactivation of chromosomal genes, and the corresponding mutant strain was assayed in each case for resistance to different concentrations of polymyxin B by measuring the percentage of surviving cells. The resistance of a double knock-out wzc-etk-mutant was also analyzed and complementation experiments were performed by checking the effect of plasmid vectors expressing either Wzc or Etk. Our results concurred in showing that protein-kinase Wzc is not essential for polymyxin resistance, whereas protein-kinase Etk appears to play a key role in such antibiotic resistance. This newly found specific function of Etk reinforces the concept that protein-tyrosine kinases are involved in distinct facets of bacterial physiology.
authors.affiliation: Institute of Biology and Chemistry of Proteins, University of Lyon/CNRS, 7, passage du Vercors 69367 Lyon Cedex 07, France.
authors.forename: Soline
authors.initials: S
authors.lastname: Lacour
authors.forename: Patricia
authors.initials: P
authors.lastname: Doublet
authors.forename: Brice
authors.initials: B
authors.lastname: Obadia
authors.forename: Alain J
authors.initials: AJ
authors.lastname: Cozzone
authors.forename: Christophe
authors.initials: C
authors.lastname: Grangeasse
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D048168:Escherichia coli K12 / Q000187:drug effects* / Q000254:growth & development; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008826:Microbial Sensitivity Tests / Q000379:methods; D016133:Polymerase Chain Reaction / Q000379:methods; D011113:Polymyxins / Q000494:pharmacology*; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; C120614:Etk protein, E coli; D008565:Membrane Proteins; D011113:Polymyxins; D011505:Protein-Tyrosine Kinases; C499615:wzc protein, E coli