Catalase HPI influences membrane permeability in Escherichia coli following near-UV stress.
The katG gene in Escherichia coli encodes catalase HPI, which is involved in membrane transport and protects the cell during oxidative stress. Hydrogen peroxide (H2O2) induces synthesis of HPI. We examined the role of HPI in membrane permeability (proline uptake) following exposure to near-ultraviolet radiation (NUV). We found that NUV resulted in the same type of induction as H2O2. KatG::Tn10 cells experienced a large drop in uptake after NUV exposure, and levels remained low following incubation. A strain carrying a katG+ plasmid, however, showed considerably less decrease in uptake after NUV, and uptake quickly resumed upon incubation. Further, in an srd mutant which lacks 4-thiouracil, NUV resulted in only a small drop in proline uptake, which was immediately resumed.
Levén
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Division of Biological Sciences, University of Missouri, Columbia 65211.
Heimberger
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Eisenstark
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D002374:Catalase / Q000235:genetics / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000528:radiation effects; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000528:radiation effects*; D005838:Genotype; D007700:Kinetics; D010957:Plasmids; D014466:Ultraviolet Rays
D002374:Catalase