Concentrative Nucleoside Transporter 1 (CNT1)

Nucleosides are involved in signaling in a number of physiologic systems, and synthetic analogs of natural nucleosides are used to treat neoplastic and viral diseases. Plasma membrane transport of nucleosides is mediated by equilibrative and concentrative nucleoside transporters, which may have specificity for purines or pyrimidines. The deduced 650-amino acid SLC28A1 protein is 83% identical to the rat protein. Northern blot analysis revealed expression of a 3.4-kb SLC28A1 transcript in kidney.SLC28A1 facilitates sodium-dependent fluxes of uridine, azidodeoxythymidine (AZT), and adenosine, but not of guanosine or deoxyadenosine, which undergoes net renal secretion. They suggested that SLC28A1 represents a potential mechanism for renal reabsorption of physiologic nucleosides and synthetic nucleoside drugs.