The role of antioxidant enzymes in response of Escherichia coli to osmotic upshift.
Aerobic growth of Escherichia coli sodAsodB and katE mutants lacking cytosolic superoxide dismutases and catalase hydroperoxidase II was inhibited by osmotic upshift to a greater extent than of their wild-type parent strains. The fur mutation leading to an intracellular overload of iron also increased sensitivity of growing E. coli cells to osmotic upshift. Using lacZ fusions, it was shown that expression of antioxidant genes soxS and katE was stimulated by an increase in osmolarity. These data suggest that in aerobically growing E. coli cells, moderate osmotic upshift causes activation of certain antioxidant systems.
Smirnova
G V
GV
Laboratory of Physiology of Microorganisms, Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Golev street 13, Perm, Russia.
Muzyka
N G
NG
Oktyabrsky
O N
ON
D000332:Aerobiosis; D001426:Bacterial Proteins / Q000235:genetics*; D002374:Catalase / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development*; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D007700:Kinetics; D009154:Mutation; D009994:Osmolar Concentration; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012097:Repressor Proteins / Q000235:genetics; D012965:Sodium Chloride / Q000494:pharmacology; D013395:Sucrose / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000235:genetics*; D001616:beta-Galactosidase / Q000235:genetics
D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C068477:ferric uptake regulating proteins, bacterial; D012965:Sodium Chloride; D013395:Sucrose; C102664:hydroperoxidase II; D002374:Catalase; C095500:SodA protein, Bacteria; C087504:SodB protein, Bacteria; D013482:Superoxide Dismutase; D001616:beta-Galactosidase