| Type: | Family | Name: | Xanthine permease XanQ/UapA |
| Description: | This family includes transporters UapA [, ] and UapC [] from Aspergillus nidulans [] and its homologue XanQ (also known as YgfO) from E. coli []. UapA and UapC are proton motive force-dependent high-affinity transporters for the oxidised purines uric acid and xanthine; XanQ only for xanthine. The are members of the nucleobase-ascorbate transporter (NAT) family, also known as nucleobase/cation symporter 2 (NCS2) family [].Regulation of UapA has been studied. Its expression is transcriptionally activated during germination, and is further induced in the presence of purines []. Downregulation occurs by a novel mechanism: in the presence of its substrates, UapA is endocytosed, sorted into the multivesicular body pathway and degraded in vacuoles []. | Short Name: | XanQ/UapA |
