Osmotic regulation of rpoS-dependent genes in Escherichia coli.
The rpoS gene, which encodes a putative alternative sigma factor (sigma S), is essential for the expression of a variety of stationary-phase-induced genes as well as for stationary-phase-specific multiple-stress resistance. As previously shown for the otsA and otsB genes (R. Hengge-Aronis, W. Klein, R. Lange, M. Rimmele, and W. Boos, J. Bacteriol. 173:7918-7924, 1991), we demonstrate here that additional rpoS-controlled genes (bolA, csi-5) as well as at least 18 proteins on two-dimensional O'Farrell gels could be induced in growing cells by osmotic upshift via an rpoS-dependent mechanism. Also, rpoS-dependent thermotolerance and resistance against hydrogen peroxide could be osmotically stimulated. In contrast, the expression of glgS, while exhibiting strong stationary-phase induction, was only weakly increased by elevated osmolarity, and several rpoS-dependent proteins previously identified on two-dimensional gels were not osmotically induced. During osmotic induction of rpoS-dependent genes, rpoS transcription and the level of sigma S remained unchanged. We conclude that osmotically regulated genes represent a subfamily within the rpoS regulon that requires differential regulation in addition to that provided by sigma S.
Hengge-Aronis
R
R
Department of Biology, University of Konstanz, Germany.
Lange
R
R
Henneberg
N
N
Fischer
D
D
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D004926:Escherichia coli / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005798:Genes, Bacterial / Q000235:genetics*; D014176:Protein Biosynthesis / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012808:Sigma Factor / Q000096:biosynthesis / Q000235:genetics*; D012965:Sodium Chloride; D014158:Transcription, Genetic / Q000187:drug effects; D014882:Water-Electrolyte Balance / Q000187:drug effects; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D012965:Sodium Chloride; D001616:beta-Galactosidase