Thyroid hormone transporters.

Abstract

Thyroid hormone transporters at the plasma membrane govern intracellular bioavailability of thyroid hormone. Monocarboxylate transporters (MCT) 8 and MCT10, organic anion transporting polypeptide (OATP) 1C1 and SLC17A4 are currently known as transporters displaying highest specificity towards thyroid hormones. Structure-function studies using homology modelling and mutational screens have led to better understanding of the molecular basis of thyroid hormone transport. Mutations in MCT8 and in OATP1C1 have been associated with clinical disorders. Different animal models have provided insight in the functional role of thyroid hormone transporters, in particular MCT8. Different treatment strategies for MCT8 deficiency have been explored, of which thyroid hormone analogue therapy is currently applied in patients. Future studies may reveal the identity of as-yet-undiscovered thyroid hormone transporters. Complementary studies employing animal and human models will provide further insight into the role of transporters in health and disease.