Discovery of the ergothioneine transporter

• DOI: 10.1073/pnas.0408624102
• Publication Date: 2005-03-29T01:14:19Z
• Authors: Dirk Gründemann; Stephanie Harlfinger; Stefan Golz; Andreas Geerts; Andreas Lazar; Reinhard Berkels; Norma Jung; Andrea Rubbert; Edgar Schömig
• Keywords: Ergothioneine; Betaine; Tetraethylammonium; Solute carrier family; HEK 293 cells

Variants of the SLC22A4 gene are associated with susceptibility to rheumatoid arthritis and Crohn's disease. codes for an integral membrane protein, OCTN1, that has been presumed carry organic cations like tetraethylammonium across plasma membrane. Here, we show key substrate this transporter is in fact ergothioneine (ET). Human OCTN1 was expressed 293 cells. A lead, stachydrine (alias proline betaine), identified by liquid chromatography MS difference shading, a new search strategy. Analysis transport efficiency stachydrine-related solutes, affinity, Na + dependence indicates physiological ET. Efficiency ET as high 195 μl per min mg protein. By contrast, carnitine OCTN2 from rat did not at all. Because transported >100 times more efficiently than carnitine, propose functional name ETT (ET transporter) instead OCTN1. ET, all which absorbed food, intracellular antioxidant metal ion affinity. Its particular purpose unresolved. Cells expression accumulate levels avidly retain it. cells lacking do because their virtually impermeable compound. The real-time PCR profile human ETT, strong CD71 cells, consistent pivotal function erythrocytes. Moreover, prominent monocytes polymorphism associations suggest protective role chronic inflammatory disorders.