title: Magnetic field exposure stimulates transposition through the induction of DnaK/J synthesis.
abstract: Like some naturally occurring environmental stress factors such as heat shock and UV irradiation, magnetic field exposure is also stimulatory to transposition activity. This feature could be illustrated by a bacterial conjugation study using an Escherichia coli strain that carries the transposable element Tn5 as the donor. When the donor cultures were exposed to a low-frequency (50 Hz) magnetic field of 1.2 mT, Tn5 located on the bacterial chromosome was stimulated to transpose and settled on the extrachromosomal episome, and eventually transferred to the recipient cell through conjugation. Such transposition activity stimulation was mediated by the induced synthesis and accumulation of the heat shock proteins DnaK/J.
authors.affiliation: Department of Biochemistry, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China. bckchow@ust.hk
authors.forename: K C
authors.initials: KC
authors.lastname: Chow
authors.forename: W L
authors.initials: WL
authors.lastname: Tung
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis; D002876:Chromosomes, Bacterial / Q000235:genetics / Q000528:radiation effects; D003227:Conjugation, Genetic; D004251:DNA Transposable Elements / Q000528:radiation effects*; D004574:Electromagnetic Fields; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D029968:Escherichia coli Proteins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics*; D006360:Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D029968:Escherichia coli Proteins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C063842:dnaK protein, E coli