Solute carrier family 22 member 4 (SLC22A4) (SLC22A4)

Solute carrier family 22 member 4 (SLC22A4), also known as Organic Cation Transporter Novel type 1 (OCTN1), is an integral membrane protein that functions as a high-affinity, sodium-dependent transporter for the dietary antioxidant ergothioneine (UniProt, 1.3.3; Wikipedia, 1.3.1). It is expressed in various tissues, including the kidney, small intestine, and immune cells such as monocytes, where it helps maintain cellular redox balance and regulates inflammatory responses (PNAS, 1.2.2; MDPI, 1.2.4). Beyond ergothioneine, SLC22A4 facilitates the transport of organic cations, carnitine, and the export of acetylcholine, contributing to the non-neuronal cholinergic system (GeneCards, 1.2.5; UniProt, 1.3.3). Genetic variants, most notably the L503F polymorphism (rs1050152), are significantly associated with susceptibility to chronic inflammatory conditions like Crohn's disease and rheumatoid arthritis (Nature Genetics, 1.3.2; MDPI, 1.2.4). The transporter also plays a critical role in the pharmacokinetics of several drugs, including gabapentin, cytarabine, and mitoxantrone, by mediating their absorption and tissue distribution (NIH, 1.3.2; GeneCards, 1.2.5). Consequently, SLC22A4 is a key factor in drug-drug interactions and individual variability in drug response (Expert Opin Drug Metab Toxicol, 1.1.1).

Other names

OCTN1 (UniProt, 1.3.3)Organic cation transporter 1 (GeneCards, 1.2.5)Ergothioneine transporter (Wikipedia, 1.3.1)ETT (PNAS, 1.2.2)Organic cation/carnitine transporter 1 (NIH, 1.3.2)DFNB60 (Wikipedia, 1.3.1)

SLC22A4 acts as a symporter or uniporter to facilitate the cellular uptake or efflux of drugs and endogenous metabolites (UniProt, 1.3.3). Drugs may act as substrates, utilizing the transporter for systemic absorption and tissue distribution, or as inhibitors that block the transport of other substrates, leading to drug-drug interactions (Expert Opin Drug Metab Toxicol, 1.1.1; NIH, 1.3.2).