Pdr5p is one of the major multidrug efflux pumps whose overexpression confers multidrug resistance (MDR) in Saccharomyces cerevisiae. By using our original assay system, a fungal strain producing inhibitors for Pdr5p was obtained and classified as Fusarium sp. Y-53. The purified inhibitors were identified as ionophore antibiotics, enniatin B, B1, and D, respectively. A non-toxic concentration of each enniatin (5 microg/ml, approximately 7.8 microM) strongly inhibited a Pdr5p-mediated efflux of cycloheximide or cerulenin in Pdr5p-overexpressing cells. The enniatins accumulated a fluorescent dye rhodamine 123, a substrate of Pdr5p, into yeast cells. The mode of Pdr5p inhibition of enniatin was competitive against FK506, and its inhibitory activity was more potent with less toxicity than that of FK506. The enniatins showed similar inhibitory profile as FK506 against S1360 mutants (S1360A and S1360F) of Pdr5p. The enniatins did not inhibit the function of Snq2p, a homologue of Pdr5p. Thus, it was found that enniatins are potent and specific inhibitors for Pdr5p, with less toxicities than that of FK506.
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http://dx.doi.org/10.1016/j.bbrc.2005.01.075 | DOI Listing |
Mar Drugs
November 2024
Laboratório de Bioquímica Microbiana, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, RJ, Brazil.
Numerous species are responsible for fungal infections; however, stands out among the others. Treatment with fluconazole is often ineffective due to the resistance phenotype mediated by transmembrane transporters and/or biofilm formation, mechanisms of resistance commonly found in strains. A previous study by our group demonstrated that batzelladine D can inhibit the Pdr5p transporter in .
View Article and Find Full Text PDFLett Appl Microbiol
April 2023
Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
Drug resistance commonly occurs when treating immunocompromized patients with fungal infections. Dehydrozingerone-a phenolic compound isolated from the rhizome of Zingiber officinale-inhibits drug efflux in Saccharomyces cerevisiae by overexpression of the ATP-binding cassette (ABC) transporter Pdr5p. We aimed to investigate whether dehydrozingerone enhances the antifungal activity of glabridin-an isoflavan isolated from the roots of Glycyrrhiza glabra L.
View Article and Find Full Text PDFJ Fungi (Basel)
July 2022
Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Avenida Carlos Chagas Filho 373, Rio de Janeiro 21941-590, Brazil.
The poor outcome of treatments for fungal infections is a consequence of the increasing incidence of resistance to antifungal agents, mainly due to the overexpression of efflux pumps. To surpass this mechanism of resistance, a substance able to inhibit these pumps could be administered in association with antifungals. possesses an efflux pump (Pdr5p) homologue to those found in pathogenic yeast.
View Article and Find Full Text PDFToxins (Basel)
February 2022
Faculty of Biotechnology and Food Science, Wrocław University of Environmental and Life Sciences, ul. Chełmońskiego 37/41, 51-630 Wrocław, Poland.
The killer strains of and species secrete antimicrobial proteins called killer toxins which are active against selected fungal phytopathogens. In our research, we attempted to investigate the role of plasma membrane pleiotropic drug resistance (PDR) transporters (Pdr5p and Snq2p) in the mechanism of defense against killer toxins. mutant strains with strengthened or weakened pleiotropic drug resistance due to increased or reduced number of mentioned PDR efflux pumps were tested for killer toxin susceptibility.
View Article and Find Full Text PDFmBio
December 2021
Synthetic Biology Laboratory, Department of Structural and Functional Biology, Institute of Biology, University of Campinas-UNICAMP, Campinas, São Paulo, Brazil.
The routes of uptake and efflux should be considered when developing new drugs so that they can effectively address their intracellular targets. As a general rule, drugs appear to enter cells via protein carriers that normally carry nutrients or metabolites. A previously developed pipeline that searched for drug transporters using Saccharomyces cerevisiae mutants carrying single-gene deletions identified import routes for most compounds tested.
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