Sodium-independent purine-selective nucleobase transporter which mediates the equilibrative transport of extracellular purine nucleobases such as adenine, guanine and hypoxanthine . May regulate fatty acid (FA) transport in adipocytes, acting as a positive regulator of FA efflux and as a negative regulator of FA uptake (By similarity). ; [Isoform 1]: Sodium-independent purine-selective nucleobase transporter which mediates the equilibrative transport of extracellular purine nucleobase adenine . Mediates the influx and efflux of the purine nucleobase analog drug 6-mercaptopurine across the membrane . ; [Isoform 2]: Sodium-independent purine-selective nucleobase transporter which mediates the equilibrative transport of extracellular purine nucleobase adenine . Mediates the influx and efflux of the purine nucleobase analog drug 6-mercaptopurine across the membrane .
show all
Cellular Localization:
Basolateral cell membrane ; Multi-pass membrane protein .
show all
Tissue Expression:
Widely expressed with highest levels in the liver and lung, followed by the pancreas (PubMed:26455426). Highly expressed in macrophages (Ref.1).