Sodium/nucleoside cotransporter 1

Sodium-dependent and pyrimidine-selective transporter. Exhibits the transport characteristics of the nucleoside transport system cit or N2 subtype (N2/cit) (selective for pyrimidine nucleosides and adenosine). Transports uridine, cytidine, thymidine, and nucleoside-derived drugs. Transports the antiviral pyrimidine nucleoside analogs 3′-azido-3′-deoxythymidine (AZT) and 2′,3′-dideoxycytidine (ddC). It may be involved in the intestinal absorption and renal handling of pyrimidine nucleoside analogs used to treat acquired immunodeficiency syndrome (AIDS). It has the following selective inhibition: adenosine, thymidine, cytidine, uridine >> guanosine, inosine.