Magnetic field exposure enhances DNA repair through the induction of DnaK/J synthesis.
In contrast to the common impression that exposure to a magnetic field of low frequency causes mutations to organisms, we have demonstrated that a magnetic field can actually enhance the efficiency of DNA repair. Using Escherichia coli strain XL-1 Blue as the host and plasmid pUC8 that had been mutagenized by hydroxylamine as the vector for assessment, we found that bacterial transformants that had been exposed to a magnetic field of 50 Hz gave lower percentages of white colonies as compared to transformants that had not been exposed to the magnetic field. This result was indicative that the efficiency of DNA repair had been improved. The improvement was found to be mediated by the induced overproduction of heat shock proteins DnaK/J (Hsp70/40).
Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, Kowloon, PR China. bckchow@ust.hk
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D001426:Bacterial Proteins / Q000096:biosynthesis / Q000378:metabolism; D018834:Chaperonin 60 / Q000378:metabolism; D004260:DNA Repair / Q000235:genetics*; D004269:DNA, Bacterial / Q000187:drug effects / Q000235:genetics; D004574:Electromagnetic Fields; D004790:Enzyme Induction; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis* / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000378:metabolism; D019811:Hydroxylamine / Q000494:pharmacology; D016296:Mutagenesis / Q000187:drug effects; D010957:Plasmids / Q000187:drug effects / Q000235:genetics
D001426:Bacterial Proteins; D018834:Chaperonin 60; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D019811:Hydroxylamine; C063842:dnaK protein, E coli