Solute carrier family 22 member 4 (OCTN1) (SLC22A4)

Solute carrier family 22 member 4 (SLC22A4), widely known as Organic cation transporter novel 1 (OCTN1), is a transmembrane protein that acts as a high-affinity transporter for the dietary antioxidant ergothioneine (UniProt: O76082). In human keratinocytes, OCTN1 is essential for the uptake of ergothioneine, which serves as a critical cytoprotectant against ultraviolet (UV) radiation and oxidative damage (PubMed: 21466631). Beyond the skin, OCTN1 is expressed in the kidneys, intestine, and inflammatory cells, where it regulates the distribution of organic cations and xenobiotics (PubMed: 15833740). The transporter is clinically significant due to its strong association with chronic inflammatory diseases; specifically, the 1507C>T (L503F) missense mutation is a recognized risk factor for Crohn's disease and rheumatoid arthritis (PubMed: 15122254). Additionally, OCTN1 mediates the transport of various therapeutic agents, such as the anticonvulsant gabapentin and certain anti-cancer drugs, influencing their bioavailability and systemic clearance (PubMed: 18451311). Consequently, OCTN1 is a key target for understanding both antioxidant defense mechanisms and the pharmacokinetics of cation-based drugs.

Other names

Organic cation transporter novel 1Ergothioneine transporterETTOCTN1Organic cation/carnitine transporter 1

Facilitates the sodium-dependent and pH-dependent uptake of ergothioneine and other organic cations across the plasma membrane into the cytoplasm.