Fig. 3.
Iodide suppression of DNA binding of nuclear protein to the NIS promoter in FRTL-5 thyroid cells. (A) The effect of iodide on DNA binding activity in the NIS 5’-flanking region was assessed by electrophoretic gel mobility shift analysis (EMSA). In (A), a solid arrow identifies a complex increased by thyrotropin (TSH), but decreased by sodium iodide (NaI). In (B), an open arrow identifies a complex decreased by NaI in the absence of TSH.