Acts as a substrate for the production of iodinated thyroid hormones thyroxine (T4) and triiodothyronine (T3). The synthesis of T3 and T4 involves iodination of selected tyrosine residues of TG/thyroglobulin followed by their oxidative coupling in the thyroid follicle lumen. Following TG re-internalization and lysosomal-mediated proteolysis, T3 and T4 are released from the polypeptide backbone leading to their secretion into the bloodstream. One dimer produces 7 thyroid hormone molecules.
