| The protein encoded by this intronless gene belongs to the iodothyronine deiodinase family. It catalyzes the inactivation of thyroid hormone by inner ring deiodination of the prohormone thyroxine (T4) and the bioactive hormone 3,3,5-triiodothyronine (T3) to inactive metabolites, 3,3,5-triiodothyronine (RT3) and 3,3-diiodothyronine (T2), respectively. This enzyme is highly expressed in pregnant uterus, placenta, fetal and neonatal tissues, and thought to prevent premature exposure of developing fetal tissues to adult levels of thyroid hormones. It regulates circulating fetal thyroid hormone concentrations, and thus plays a critical role in mammalian development. Knockout mice lacking this gene exhibit abnormalities related to development and reproduction, and increased activity of this enzyme in infants with hemangiomas causes severe hypothyroidism. This proteicatalytic activity:3,3,5-triiodo-L-thyronine + iodide + A + H(+) = L-thyroxine + AH(2).,function:Responsible for the deiodination of T4 (3,5,3,5-tetraiodothyronine) into RT3 (3,3,5-triiodothyronine) and of T3 (3,5,3-triiodothyronine) into T2 (3,3-diiodothyronine). RT3 and T2 are inactive metabolites. May play a role in preventing premature exposure of developing fetal tissues to adult levels of thyroid hormones. Can regulate circulating fetal thyroid hormone concentrations throughout gestation. Essential role for regulation of thyroid hormone inactivation during embryological development.,function:Responsible for the deiodination of T4 (3,5,3,5-tetraiodothyronine).,similarity:Belongs to the iodothyronine deiodinase family.,tissue specificity:Expressed in placenta and several fetal tissues., |
