Fluorescent nucleoside derivatives as a tool for the detection of concentrative nucleoside transporter activity using confocal microscopy and flow cytometry.

The abundance and function of transporter proteins at the plasma membrane are likely to be crucial in drug responsiveness. Functional detection of human concentrative nucleoside transporters (hCNTs) is of interest for predicting drug sensitivity because of their ability to transport most nucleoside-derived drugs. In the present study, two fluorescent nucleoside analogues, uridine-furan and etheno-cytidine, were evaluated as tools to study in vivo nucleoside transporter-related functions.

rCNT2 extracellular cysteines, Cys(615) and Cys(649), are important for maturation and sorting to the plasma membrane.

rCNT2 is a purine-preferring concentrative nucleoside transporter implicated in the regulation of extracellular adenosine levels and purinergic signaling. This study addressed the analysis of the CNT2 C-terminus tail as a domain likely to be implicated in transporter sorting. The topological mapping of this segment revealed that Cys(615) and Cys(649) are important residues for the proper trafficking of CNT2 to the plasma membrane.