Membrane rafts are involved in intracellular miconazole accumulation in yeast cells.
Azoles inhibit ergosterol biosynthesis, resulting in ergosterol depletion and accumulation of toxic 14alpha-methylated sterols in membranes of susceptible yeast. We demonstrated previously that miconazole induces actin cytoskeleton stabilization in Saccharomyces cerevisiae prior to induction of reactive oxygen species, pointing to an ancillary mode of action. Using a genome-wide agar-based screening, we demonstrate in this study that S. cerevisiae mutants affected in sphingolipid and ergosterol biosynthesis, namely ipt1, sur1, skn1, and erg3 deletion mutants, are miconazole-resistant, suggesting an involvement of membrane rafts in its mode of action. This is supported by the antagonizing effect of membrane raft-disturbing compounds on miconazole antifungal activity as well as on miconazole-induced actin cytoskeleton stabilization and reactive oxygen species accumulation. These antagonizing effects point to a primary role for membrane rafts in miconazole antifungal activity. We further show that this primary role of membrane rafts in miconazole action consists of mediating intracellular accumulation of miconazole in yeast cells.
François
Isabelle E J A
IE
Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, 3001 Heverlee, Belgium.
Bink
Anna
A
Vandercappellen
Jo
J
Ayscough
Kathryn R
KR
Toulmay
Alexandre
A
Schneiter
Roger
R
van Gyseghem
Elke
E
Van den Mooter
Guy
G
Borgers
Marcel
M
Vandenbosch
Davy
D
Coenye
Tom
T
Cammue
Bruno P A
BP
Thevissen
Karin
K
D000935:Antifungal Agents / Q000493:pharmacokinetics; D025141:Drug Resistance, Fungal; D004705:Endocytosis; D004875:Ergosterol / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D016681:Genome, Fungal; D021962:Membrane Microdomains / Q000187:drug effects / Q000378:metabolism*; D008825:Miconazole / Q000493:pharmacokinetics* / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010742:Phospholipid Ethers / Q000494:pharmacology; D017382:Reactive Oxygen Species; D012441:Saccharomyces cerevisiae / Q000378:metabolism*
D000935:Antifungal Agents; D010726:Phosphodiesterase Inhibitors; D010742:Phospholipid Ethers; D017382:Reactive Oxygen Species; C026659:edelfosine; D008825:Miconazole; D004875:Ergosterol