title: Induced expression of the Candida albicans multidrug resistance gene CDR1 in response to fluconazole and other antifungals.
abstract: The Candida albicans CDR1 gene encodes a member of the ABC-type family of multidrug transporters which has been shown to be involved in azole resistance. Using an in-frame gene fusion between the CDR1 open reading frame and the green fluorescent protein allele yEGFP3, an optimized derivative for its use in C. albicans, we show here how the CDR1-yEGFP3 gene expression is induced in response to azoles as well as to other structurally unrelated drugs like cycloheximide. Moderate increases were observed for calcofluor, canavanine, 5'-fluorcytosine, cilofungin and caffeine, while no induction was found for the antifungals benomyl and amphotericin B or hydrogen peroxide at subinhibitory concentrations. The use of confocal microscopy enabled us to localize the Cdr1p fusion protein at the cell periphery, thus suggesting a cytoplasmic membrane localization. These results suggest deregulation of CDR1 gene as a putative mechanism for the generation of azole resistance in this clinically important pathogenic fungus.
authors.affiliation: Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, Spain.
authors.forename: M L
authors.initials: ML
authors.lastname: Hernáez
authors.forename: C
authors.initials: C
authors.lastname: Gil
authors.forename: J
authors.initials: J
authors.lastname: Pla
authors.forename: C
authors.initials: C
authors.lastname: Nombela
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000032:analysis / Q000235:genetics*; D000935:Antifungal Agents / Q000494:pharmacology*; D019677:Artificial Gene Fusion; D002176:Candida albicans / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D004352:Drug Resistance, Microbial / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics*; D005434:Flow Cytometry; D015725:Fluconazole / Q000494:pharmacology*; D005656:Fungal Proteins / Q000032:analysis / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics; D026901:Membrane Transport Proteins; D018613:Microscopy, Confocal; D011993:Recombinant Fusion Proteins / Q000032:analysis; D014170:Transformation, Genetic
chemical_list: D018528:ATP-Binding Cassette Transporters; D000935:Antifungal Agents; C094693:CDR1 protein, Candida albicans; D005656:Fungal Proteins; D008164:Luminescent Proteins; D026901:Membrane Transport Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D015725:Fluconazole