InterPro domain: IPR030189

This entry represents ureide permeases (UPSs) from plants, including Arabodopsis AtUPS1-5. They are transporters for allantoin and other oxo derivatives of nitrogen heterocyclic compounds. In Arabidopsis, the UPS family members have distinct and partially overlapping expression patterns with regard to developmental stages or tissue specific localisation [ 1 ]. AtUPS1 may be involved in the uptake of allantoin and other purine degradation products when primary sources are limiting [ 2 ]. AtUPS1 and AtUPS2 mediate high affinity transport of uracil and 5-fluorouracil [ 3 ]. AtUPS5 has two isoforms, long and short. The short isoform of ATUPS5 lacks two transmembrane domains and may be defective in transporting cyclic purine degradation products and pyrimidines [ 4 ].

1. Comparative studies on Ureide Permeases in Arabidopsis thaliana and analysis of two alternative splice variants of AtUPS5. Planta 224, 1329-40
2. A novel superfamily of transporters for allantoin and other oxo derivatives of nitrogen heterocyclic compounds in Arabidopsis. Plant Cell 14, 847-56
3. UPS1 and UPS2 from Arabidopsis mediate high affinity transport of uracil and 5-fluorouracil. J. Biol. Chem. 279, 44817-24