Nucleoside transporters of parasitic protozoa.

Protozoan parasites are incapable of synthesizing purine nucleotides de novo and so must salvage preformed purines from their hosts. This process of purine acquisition is initiated by the translocation of preformed host purines across parasite or host membranes. Here, we report upon the identification and isolation of DNAs encoding parasite nucleoside transporters and the functional characterization of these proteins in various expression systems. These potential approaches provide a powerful approach for a thorough molecular and biochemical dissection of nucleoside transport in protozoan parasites.