Sodium Coupled Monocarboxylate Transporter 1 (SMCT)

SLC5A8 has been shown to transport iodide by a passive mechanism and monocarboxylates and short-chain fatty acids by a sodium-coupled mechanism. In kidney, SLC5A8 functions as a high-affinity sodium-coupled lactate transporter involved in reabsorption of lactate and maintenance of blood lactate levels.The deduced 610-amino acid protein contains 13 putative transmembrane domains, 2 potential N-glycosylation sites, and several sites for serine and threonine phosphorylation. AIT shares 46% amino acid identity with NIS. RT-PCR showed that expression of AIT was 10 times higher in thyroid than in kidney. Immunolocalization of AIT in thyroid detected apical staining of thyrocytes. Staining was heterogenous between follicles, and inside any given follicle, only half of the thyrocytes were stained.