title: Role of the mar-sox-rob regulon in regulating outer membrane porin expression.
abstract: Multiple factors control the expression of the outer membrane porins OmpF and OmpC in Escherichia coli. In this work, we investigated the role of the mar-sox-rob regulon in regulating outer membrane porin expression in response to salicylate. We provide both genetic and physiological evidence that MarA and Rob can independently activate micF transcription in response to salicylate, leading to reduced OmpF expression. MarA was also found to repress OmpF expression through a MicF-independent pathway. In the case of OmpC, we found that its transcription was moderately increased in response to salicylate. However, this increase was independent of MarA and Rob. Finally, we found that the reduction in OmpF expression in a tolC mutant is due primarily to Rob. Collectively, this work further clarifies the coordinated role of MarA and Rob in regulating the expression of the outer membrane porins.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801, USA.
authors.forename: Lon M
authors.initials: LM
authors.lastname: Chubiz
authors.forename: Christopher V
authors.initials: CV
authors.lastname: Rao
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D018272:Porins / Q000235:genetics / Q000378:metabolism*; D018085:Regulon / Q000502:physiology*; D055747:SOX Transcription Factors / Q000235:genetics / Q000378:metabolism*; D012459:Salicylates; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C080002:MarA protein, E coli; C113724:OmpC protein; C109237:OmpF protein; D018272:Porins; C080267:Rob protein, E coli; D055747:SOX Transcription Factors; D012459:Salicylates