Transporter that mediates the transport of endogenous and microbial zwitterions and organic cations (   , ). Functions as a Na(+)-dependent and pH-dependent high affinity microbial symporter of potent food-derived antioxidant ergothioeine ( ). Transports one sodium ion with one ergothioeine molecule (By similarity). Involved in the absorption of ergothioneine from the luminal/apical side of the small intestine and renal tubular cells, and into non-parenchymal liver cells, thereby contributing to maintain steady-state ergothioneine level in the body . Also mediates the bidirectional transport of acetycholine, although the exact transport mechanism has not been fully identified yet . Most likely exports anti-inflammatory acetylcholine in non-neuronal tissues, thereby contributing to the non-neuronal cholinergic system (, ). Displays a general physiological role linked to better survival by controlling inflammation and oxidative stress, which may be related to ergothioneine and acetycholine transports (, ). May also function as a low-affinity Na(+)-dependent transporter of L-carnitine through the mitochondrial membrane, thereby maintaining intracellular carnitine homeostasis ( ). May contribute to regulate the transport of cationic compounds in testis across the blood-testis-barrier .
Subcellular locations: Apical cell membrane, Basal cell membrane, Mitochondrion membrane
Localized to the apical membrane of small intestines . Localized to the basal membrane of Sertoli cells .
Widely expressed . Highly expressed in kidney, trachea, ileum, bone marrow and whole blood (, ). Expressed in small intestines . Weakly expressed in skeletal muscle, prostate, lung, pancreas, placenta, heart, uterus, spleen and spinal cord ( ). Expressed in testis, primarily to the basal membrane of Sertoli cells (, ). Expressed in brain . Expressed in liver . Highly expressed in intestinal cell types affected by Crohn disease, including epithelial cells. Expressed in CD68 macrophage and CD43 T-cells but not in CD20 B-cells . Predominantly expressed in CD14 cells in peripheral blood mononuclear cells . Expressed in fetal liver, kidney and lung (, ).