Purification and characterization of thyroid transcription factor 2

Thyroid transcription factor 2 binds to the promoters of both thyroglobulin and thyroperoxidase genes, two markers of thyroid tissue differentiation, and its binding modulates the activity of both promoters. In this paper we describe the purification of thyroid transcription factor 2 essentially to homogeneity and demonstrate that it is a thyroid-specific DNA-binding protein. Furthermore, we provide a biochemical characterization suggesting that thyroid transcription factor 2 binds to DNA as a dimer and that it is a zinc-finger DNA-binding protein regulated in vitro by the redox state.