CLONING OF A NEW FRTL5-DERIVED CELL-LINE STABLY EXPRESSING ACTIVE HUMAN THYROID PEROXIDASE

A full-length cDNA clone for human thyroid peroxidase inserted into th e mammalian cell expression vector pECE was stably transfected into th e rat thyroid cell line FRTL5. Clones expressed immunologically and en zymatically assessed human thyroid peroxidase protein. Methimazole (25 mu M) inhibited the thyroid peroxidase activity dose-dependently and this effect was completely antagonised by 100 mu M NaI. Ethylenethiour ea, metabolite of dithiocarbamate pesticides, inhibited the enzyme at 50 mu M. Thus, we have obtained thyroidal cells stably expressing enzy matically active human thyroid peroxidase which can be pharmacological ly modulated and studied. (C) 1995 Academic Press, Inc.