title: Putative orotate transporter of Cryptococcus neoformans, Oat1, is a member of the NCS1/PRT transporter super family and its loss causes attenuation of virulence.
abstract: It is well known that 5-fluoroorotic acid (5-FOA)-resistant mutants isolated from wild-type Cryptococcus neoformans are exclusively either ura3 or ura5 mutants. Unexpectedly, many of the 5-FOA-resistant mutants isolated in our selective regime were Ura+. We identified CNM00460 as the gene responsible for these mutations. Cnm00460 belongs to the nucleobase cation symporter 1/purine-related transporter (NCS1/PRT) super family of fungal transporters, representative members of which are uracil transporter, uridine transporter and allantoin transporter of Saccharomyces cerevisiae. Since the CNM00460 gene turned out to be involved in utilization of orotic acid, most probably as transporter, we designated this gene Orotic Acid Transporter 1 (OAT1). This is the first report of orotic acid transporter in this family. C. neoformans has four members of the NCS1/PRT family, including Cnm00460, Cnm02550, Cnj00690, and Cnn02280. Since the cnm02550∆ strain showed resistance to 5-fluorouridine, we concluded that CNM02550 encodes uridine permease and designated it URidine Permease 1 (URP1). We found that oat1 mutants were sensitive to 5-FOA in the medium containing proline as nitrogen source. A mutation in the GAT1 gene, a positive transcriptional regulator of genes under the control of nitrogen metabolite repression, in the genetic background of oat1 conferred the phenotype of weak resistance to 5-FOA even in the medium using proline as nitrogen source. Thus, we proposed the existence of another orotic acid utilization system (tentatively designated OAT2) whose expression is under the control of nitrogen metabolite repression at least in part. We found that the OAT1 gene is necessary for full pathogenic activity of C. neoformans var. neoformans.
authors.affiliation: Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chiba, 260-8673, Japan. toh-e@faculty.chiba-u.jp.
authors.forename: Akio
authors.initials: A
authors.lastname: Toh-E
authors.affiliation: Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chiba, 260-8673, Japan.
authors.forename: Misako
authors.initials: M
authors.lastname: Ohkusu
authors.affiliation: Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chiba, 260-8673, Japan.|Tokyo University of Science, 5-3-1 Sinjuku, Katsusika-ku, Tokyo, 125-0051, Japan.
authors.forename: Kiminori
authors.initials: K
authors.lastname: Shimizu
authors.affiliation: Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chiba, 260-8673, Japan.
authors.forename: Azusa
authors.initials: A
authors.lastname: Takahashi-Nakaguchi
authors.affiliation: Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chiba, 260-8673, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kawamoto
authors.affiliation: Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chiba, 260-8673, Japan.
authors.forename: Naruhiko
authors.initials: N
authors.lastname: Ishiwada
authors.affiliation: Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chiba, 260-8673, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Watanabe
authors.affiliation: Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chiba, 260-8673, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Kamei
mesh_terms: D001692:Biological Transport / Q000235:genetics*; D003455:Cryptococcus neoformans / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D026901:Membrane Transport Proteins / Q000235:genetics*; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism; D009963:Orotic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D014498:Uracil / Q000378:metabolism
chemical_list: D026901:Membrane Transport Proteins; D014498:Uracil; D009963:Orotic Acid; C001242:5-fluoroorotic acid; D009584:Nitrogen
keywords: 5-FOA; Nitrogen metabolite repression; Orotate permease; Pyrimidine pathway