A magnetic field-responsive domain in the human HSP70 promoter

HSP70 gene expression is induced by a wide range of environmental stimuli, including 60-Hz electromagnetic fields. In an earlier report we showed that the induction of HSP70 gene expression by magnetic fields is effected at the level of transcription and is mediated through c-myc protein binding at two nCTCTn sequences at -230 and -160. in the human HSP70 promoter. We report on the identification of a third c-myc binding site (between -158 and -162) that is an important regulator of magnetic field-induced HSP70 expression. We also show that the heat shock element (HSE), lying between -180 and -203, is required for induction of HSP70 gene expression by magnetic fields. The HSE centered at -100 alone is insufficient.