<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Vlanti, Anna</style></author><author><style face="normal" font="default" size="100%">Diallinas, George</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The Aspergillus nidulans FcyB cytosine-purine scavenger is highly expressed during germination and in reproductive compartments and is downregulated by endocytosis.</style></title><secondary-title><style face="normal" font="default" size="100%">Mol Microbiol</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Asexual</style></keyword><keyword><style  face="normal" font="default" size="100%">Aspergillus fumigatus</style></keyword><keyword><style  face="normal" font="default" size="100%">Aspergillus nidulans</style></keyword><keyword><style  face="normal" font="default" size="100%">Cloning</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytosine</style></keyword><keyword><style  face="normal" font="default" size="100%">Endocytosis</style></keyword><keyword><style  face="normal" font="default" size="100%">Fungal</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes</style></keyword><keyword><style  face="normal" font="default" size="100%">Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Hyphae</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Nucleobase Transport Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Purines</style></keyword><keyword><style  face="normal" font="default" size="100%">Quaternary Ammonium Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Reproduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Transcription</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008 May</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">68</style></volume><pages><style face="normal" font="default" size="100%">959-77</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We cloned and characterized an Aspergillus nidulans gene, called fcyB, encoding the closest homologue to the yeast Fcy2p/Fcy21p permeases. Deletion of fcyB (DeltafcyB) does not affect growth, development, reproduction or bulk purine uptake, but eliminates the leaky growth on purines of DeltaazgADeltauapCDeltauapA strains, lacking all known purine transporters, and confers resistance to the antifungal 5-fluorocytosine. Kinetic analyses showed FcyB is a low-capacity, high-affinity, cytosine-purine transporter sharing similar molecular interactions for substrate recognition with the yeast Fcy2p/Fcy21p carriers. fcyB transcription is highly activated during germination but drops at low constitutive levels throughout vegetative development. UaY-mediated purine induction of fcyB transcription is only moderate, while ammonium represses transcription through an AreA-dependent mechanism. A strain expressing FcyB-GFP confirms a low protein expression level in the plasma membrane of vegetative mycelia, but reveals an abundant expression in sexual and asexual compartments. FcyB-GFP was also shown to be downregulated by endocytosis in response to ammonia or the presence of cytosine. The expression profile of FcyB supports that its main physiological role is cytosine-purine scavenging.</style></abstract></record></records></xml>