Mitochondrial ornithine transporter 2 (SLC25A2)

Mitochondrial ornithine transporter 2 (SLC25A2) is a member of the solute carrier family 25, localized in the inner mitochondrial membrane, where it mediates the transport of ornithine and related basic amino acids (lysine, arginine, citrulline, histidine) between the cytoplasm and mitochondrial matrix. It functions primarily as an exchanger and is essential for the proper functioning of the urea cycle, facilitating the fixation of ammonia for detoxification. SLC25A2 is widely expressed, most strongly in the liver, kidney, pancreas, and several other tissues. It has a broader substrate specificity than its paralog SLC25A15 (ORC1), and its activity can partially compensate for ORC1 deficiency in hyperornithinemia-hyperammonemia-homocitrullinuria syndrome (HHH), though SLC25A2 itself has not been directly linked to human disease as the sole causative gene. The transporter is inhibited by the polyamine spermine. No approved therapeutics specifically target SLC25A2; its biologically critical function places it among potential therapeutic targets related to metabolic or mitochondrial disease, though clinical targeting is currently limited.

Other names

ORC2ORNT2Solute carrier family 25 member 2Mitochondrial ornithine transporter 2solute carrier family 25 (mitochondrial carrier; ornithine transporter) member 2

Exchange (counter-transport) of ornithine, citrulline, and basic amino acids across the mitochondrial inner membrane