Passive I- efflux mediated by SMCT1 Authored: Jassal, B, 2009-07-21 Edited: Jassal, B, 2009-07-21 Pubmed12107270 Reactome Database ID Release 43429767 Reactome, http://www.reactome.org ReactomeREACT_19251 Reviewed: He, L, 2009-08-24 SLC5A8 encodes for the apical iodide transporter, AIT (also known as SMCT1). As well as functioning as a Na+-dependent monocarboxylate co-transporter, AIT also mediates iodide transport from the thyrocyte into the colloid lumen through the apical membrane (Rodriguez AM et al, 2002). AIT, together with NIS (see previous reaction), mediates iodide transfer from blood to the colloid lumen of thyrocytes.