A new hexose transporter from Cryptococcus neoformans: molecular cloning and structural and functional characterization.
We carried out a screen for Cryptococcus neoformans genes involved in resistance to copper ion toxicity and identified a new hexose transporter (Hxt) gene, HXT1. Hxt1 consists of 520 amino acids and functions to transport hexoses such as glucose. Although Hxt1 conferred copper resistance to Saccharomyces cerevisiae, disruption of the HXT1 gene showed that Hxt1 is not necessary for copper resistance. In virulence tests, an hxt1 mutant strain showed 12% less phenoloxidase activity than the wild-type strain, and no difference in the ability to form melanin was identified. In addition, the hxt1 mutant strain showed virulence similar to that of the wild-type strain in experiments with Caenorhabditis elegans. However, the hxt1 mutant strain generated larger capsules than were generated by the wild-type strain. Thus, Hxt1 appears to be involved in capsule formation.
Chikamori
Minoru
M
Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, Chuo-ku, Chiba 260-8673, Japan.
Fukushima
Kazutaka
K
D000818:Animals; D017173:Caenorhabditis elegans / Q000187:drug effects / Q000254:growth & development; D003001:Cloning, Molecular; D003300:Copper / Q000494:pharmacology* / Q000633:toxicity; D003455:Cryptococcus neoformans / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D018076:DNA, Complementary; D025141:Drug Resistance, Fungal / Q000187:drug effects / Q000235:genetics*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D009004:Monosaccharide Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D014774:Virulence
D018076:DNA, Complementary; D005656:Fungal Proteins; D009004:Monosaccharide Transport Proteins; D003300:Copper