title: Isolation and functional analysis of the KlPDR16 gene.
abstract: The fight against multidrug-resistant pathogens requires an understanding of the underlying cellular mechanisms. In this work, we isolate and characterize one of the multidrug resistance determinants in Kluyveromyces lactis, the KlPDR16 gene. We show that KlPdr16p (345 aa), which belongs to the KlPdr1p regulon, is a functional homologue of the Saccharomyces cerevisiae Pdr16p. Deletion of KlPDR16 resulted in hypersensitivity of K. lactis cells to antifungal azoles, oligomycin, rhodamine 6G, 4-nitroquinoline-N-oxide and alkali metal cations. The Klpdr16∆ mutation led to a decreased content of ergosterol in whole-cell extract. In spite of the hypersensitivity of Klpdr16∆ mutant cells to rhodamine 6G and oligomycin, the transcript level of the KlPDR5 gene and the rhodamine 6G efflux in the mutant was the same as in the parental strain. Increased accumulation of rhodamine 6G in Klpdr16∆ cells indicates that KlPDR16 limits the rate of passive drug diffusion across the membrane, without affecting the glucose-induced drug export. The results obtained show that KlPDR16, similar to its orthologues in other yeast species, influences the passive drug diffusion into the yeast cell.
authors.affiliation: Department of Microbiology and Virology, Comenius University in Bratislava, Bratislava, Slovak Republic.
authors.forename: Eduard
authors.initials: E
authors.lastname: Goffa
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Balazfyova
authors.forename: Nora
authors.initials: N
authors.lastname: Toth Hervay
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Simova
authors.forename: Maria
authors.initials: M
authors.lastname: Balazova
authors.forename: Peter
authors.initials: P
authors.lastname: Griac
authors.forename: Yvetta
authors.initials: Y
authors.lastname: Gbelska
mesh_terms: D000468:Alkalies / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology; D003001:Cloning, Molecular; D026141:Drug Resistance, Multiple, Fungal / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D017353:Gene Deletion; D007716:Kluyveromyces / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D050356:Lipid Metabolism; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data
chemical_list: D000468:Alkalies; D000935:Antifungal Agents; D005656:Fungal Proteins
keywords: Kluyveromyces lactis; ergosterol content; multidrug resistance; rhodamine 6G