title: Osmoregulation of the HtrA (DegP) protease of Escherichia coli: an Hha-H-NS complex represses HtrA expression at low osmolarity.
abstract: The HtrA protein of Escherichia coli is a heat-shock inducible periplasmic protease, essential for bacterial survival at high temperatures. Expression of htrA gene depends on the alternative factor sigmaE and on the two-component regulatory system Cpx. These regulators systems respond, among others factors, to overproduction of misfolded proteins in the periplasm or to high level synthesis of various extracytoplasmic proteins. We describe in this report the osmoregulation of the expression of htrA gene. Low osmolarity conditions result in htrA repression. We report, as well, the role of the nucleoid associated proteins H-NS and Hha in the repression of htrA expression at low osmolarity.
authors.affiliation: Departament de Microbiologia, Universitat de Barcelona, Avda. Diagonal, 645, 08028 Barcelona, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Forns
authors.forename: Antonio
authors.initials: A
authors.lastname: Juárez
authors.forename: Cristina
authors.initials: C
authors.lastname: Madrid
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology*; D024202:Electrophoretic Mobility Shift Assay; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D050939:Gene Fusion; D017930:Genes, Reporter; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D009154:Mutation; D009994:Osmolar Concentration; D033903:Periplasmic Proteins / Q000096:biosynthesis*; D012329:RNA, Bacterial / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D012697:Serine Endopeptidases / Q000096:biosynthesis*; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C031908:H-NS protein, bacteria; D006360:Heat-Shock Proteins; D033903:Periplasmic Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; C079209:hha protein, E coli; D001616:beta-Galactosidase; C061682:DegP protease; D012697:Serine Endopeptidases