Mediates both influx and efflux of nucleosides across the membrane (equilibrative transporter). It is sensitive (ES) to low concentrations of the inhibitor nitrobenzylmercaptopurine riboside (NBMPR) and is sodium-independent. It has a higher affinity for adenosine. Inhibited by dipyridamole and dilazep (anticancer chemotherapeutics drugs). Vmax for adenosine uptake is about the same for SLC29A1 and SLC29A2. Identified in a complex with STOM. Predominantly localized in the basolateral membrane in polarized MDCK cells. Detected in erythrocytes (at protein level). Expressed in heart, brain, mammary gland, erythrocytes and placenta, and also in fetal liver and spleen. Glycosylated. Belongs to the SLC29A/ENT transporter (TC 2.A.57) family.