title: Post-transcriptional control of the Escherichia coli PhoQ-PhoP two-component system by multiple sRNAs involves a novel pairing region of GcvB.
abstract: PhoQ/PhoP is a central two-component system involved in magnesium homeostasis, pathogenicity, cell envelope composition, and acid resistance in several bacterial species. The small RNA GcvB is identified here as a novel direct regulator of the synthesis of PhoQ/PhoP in Escherichia coli, and this control relies on a novel pairing region of GcvB. After MicA, this is the second Hfq-dependent small RNA that represses expression of the phoPQ operon. Both MicA and GcvB bind phoPQ mRNA in vivo and in vitro around the translation initiation region of phoP. Binding of either small RNA is sufficient to inhibit ribosome binding and induce mRNA degradation. Surprisingly, however, MicA and GcvB have different effects on the levels of the PhoP protein and therefore on the expression of the PhoP regulon. These results highlight the complex connections between small RNAs and transcriptional regulation networks in bacteria.
authors.affiliation: UPR9073 du CNRS, Université Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, Paris, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Coornaert
authors.forename: Claude
authors.initials: C
authors.lastname: Chiaruttini
authors.forename: Mathias
authors.initials: M
authors.lastname: Springer
authors.forename: Maude
authors.initials: M
authors.lastname: Guillier
mesh_terms: D045647:DNA Glycosylases / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000096:biosynthesis / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D008274:Magnesium / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D020871:RNA Stability / Q000235:genetics; D018085:Regulon; D012270:Ribosomes / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; C465562:PhoP protein, E coli; C576029:PhoQ protein, E coli; D045647:DNA Glycosylases; C061738:mutY adenine glycosylase; D008274:Magnesium