Transport of (sulfated) iodothyronines across the plasma membrane is required for their intracellular metabolism. Rat Na+/taurocholate cotransporting polypeptide (Ntcp; Slc10a1) has been identified as an important transporter protein. We demonstrate that among the 7 members of the solute carrier family SLC10, only human SLC10A1 mediates sodium-dependent transport of the iodothyronine T4 and iodothyronine sulfates T3S and T4S. In contrast to SLC10A2-7, cells co-expressing SLC10A1 and the deiodinase D1 demonstrate a dramatic increase in T3S and T4S metabolism. The SLC10A1 substrates taurocholate, DHEAS and E3S inhibit T3S and T4S transport. Furthermore, co-transfection of SLC10A1 with CRYM, a well-known intracellular iodothyronine-binding protein, results in an enhanced intracellular accumulation of T3S and T4S, indicating that CRYM binds iodothyronine sulfates. The present findings indicate that the liver-specific transporter SLC10A1 transports (sulfated) iodothyronines, thereby increasing their intracellular availability. Therefore, SLC10A1 may fulfill a critical step in providing liver D1 with iodothyronine sulfates for rapid degradation.

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doi.org/10.1016/j.mce.2009.08.003, hdl.handle.net/1765/27937
Molecular and Cellular Endocrinology
Erasmus MC: University Medical Center Rotterdam

Visser, W.E, Wong, W.S, van Mol-van Mullem, A.A.A, Friesema, E.C.H, & Geyer, J. (2010). Study of the transport of thyroid hormone by transporters of the SLC10 family. Molecular and Cellular Endocrinology, 315(1-2), 138–145. doi:10.1016/j.mce.2009.08.003