Simultaneous resistance to an array of drugs with different cytotoxic activities is a property of Saccharomyces cerevisiae, in which the protein Pdr3p has recently been shown to play a role as a transcriptional regulator. We provide evidence that the yeast PDR3 gene, which encodes a zinc finger transcription factor implicated in certain drug resistance phenomena, is under positive autoregulatio...

Analysis of the transport functions of individual Candida albicans plasma membrane drug efflux pumps is hampered by the multitude of endogenous transporters. We have stably expressed C. albicans Cdr1p, the major pump implicated in multiple-drug-resistance phenotypes, from the genomic PDR5 locus in a Saccharomyces cerevisiae mutant (AD1-8u(-)) from which seven major transporters of the ATP-bindi...

Deletion of PDR5 gene (Deltapdr5) in Saccharomyces cerevisiae led to increased resistance to calcium. The cellular Ca2+ level in the presence of high calcium as estimated by reporter assay in Deltapdr5 cells was significantly lower than that in wild-type cells. Membrane Pdr5p levels diminished rapidly during incubation with high calcium in a manner dependent on calcineurin and Pep4p, suggesting...

fungal pathogen in humans, causes diseases varying from superficial mucosal complaints to life-threatening systemic disorders. Coincident with the increased use of antifungal drugs, the incidences of drug resistance have also increased. In recent years, the development of multidrug resistance in clinical isolates has challenged effective treatment of the infections. Specifically, the extensive ...

Pdr5 is a major ATP-binding cassette (ABC) multidrug transporter regarded as the founding member of a fungal subfamily of clinically significant efflux pumps. When these proteins are overexpressed, they confer broad-spectrum ultraresistance. To better understand the evolution of these proteins under selective pressure, we exposed a Saccharomyces cerevisiae yeast strain already overexpressing Pd...

Multiple or pleiotropic drug resistance in the yeast Saccharomyces cerevisiae requires the expression of several ATP binding cassette transporter-encoding genes under the control of the zinc finger-containing transcription factor Pdrlp. The ATP binding cassette transporter-encoding genes regulated by Pdrlp include PDR5 and YOR1, which are required for normal cycloheximide and oligomycin toleran...

Saccharomyces cerevisiae has long been used as a model organism in the study of the ergosterol pathway and its inhibitors. The Pdr5 protein (Pdr5p), an ATP binding cassette transporter, plays an important role in active efflux of azole antifungals and therefore in azole sensitivity and resistance in S. cerevisiae. We have identified the Fluconazole Dominant Resistance-1 (FDR-1) mutant, which ha...

Citrinin (CIT) and ochratoxin A (OTA) are important mycotoxins, which frequently co-contaminate foodstuff. In order to assess the toxicologic threat posed by the two mycotoxins separately or in combination, their biological effects were studied here using genomic transcription profiling and specific live cell gene expression reporters in yeast cells. Both CIT and OTA cause highly transient tran...

Capsaicin is a pungent element in a variety of red peppers that are widely used as food additives and considered to be an antimicrobial factor. For our tests, we used yeast DNA micro-array methods to understand the mechanisms of inhibitory effects of capsaicin. The capsaicin treatment significantly induced 39 genes from approximately 6,000 genes. These induced genes were classified as multi-dru...