title: Differential expression of the Escherichia coli autoaggregation factor antigen 43.
abstract: Antigen 43 (Ag43) is a self-recognizing surface adhesin found in most Escherichia coli strains. Due to its excellent cell-to-cell aggregation characteristics, Ag43 expression confers clumping and fluffing of cells and promotes biofilm formation. Ag43 expression is repressed by the cellular redox sensor OxyR. Here we used mutant versions of OxyR that are locked in either the reduced or the oxidized form as well as the addition of a simple redox-changing chemical to show that the redox state of OxyR influences Ag43 expression. Furthermore, the redox state of OxyR influences the biofilm-forming potential of E. coli. Finally, we demonstrated that Ag43-mediated cell aggregation confers significant protection against hydrogen peroxide killing.
authors.affiliation: Microbial Adhesion Group, BioCentrum-DTU, Technical University of Denmark, DK-2800 Lyngby, Denmark.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Schembri
authors.forename: Louise
authors.initials: L
authors.lastname: Hjerrild
authors.forename: Morten
authors.initials: M
authors.lastname: Gjermansen
authors.forename: Per
authors.initials: P
authors.lastname: Klemm
mesh_terms: D018829:Adhesins, Bacterial; D018830:Adhesins, Escherichia coli; D000942:Antigens, Bacterial; D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms; D004268:DNA-Binding Proteins; D004229:Dithiothreitol / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology; D010084:Oxidation-Reduction; D011401:Promoter Regions, Genetic; D015202:Protein Engineering / Q000379:methods; D019163:Reducing Agents / Q000494:pharmacology; D012097:Repressor Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
chemical_list: D018829:Adhesins, Bacterial; D018830:Adhesins, Escherichia coli; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D016877:Oxidants; D019163:Reducing Agents; D012097:Repressor Proteins; D014157:Transcription Factors; C118376:antigen 43, E coli; C499299:oxyR protein, E coli; D006861:Hydrogen Peroxide; D004229:Dithiothreitol