SLC22A4

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..

Function from UniProtKB (Q9H015), read 2026-09-23. CC BY 4.0.