The human tumour suppressor gene SLC5A8 encodes sodium-coupled monocarboxylate transporter 1, SMCT1 (also called AIT) and is abundantly expressed in the colon (Coady et al. 2004, Myauchi et al. 2004). When the human protein is expressed in Xenopus oocytes, it was found to transport small monocarboxylates and carboxylate drugs, co-transporting Na+ ions electrogenically (3 Na+ ions co-transported with 1 carboxylate).
monocarboxylic acid transmembrane transporter activity of SLC5A8 [plasma membrane]