title: Sensitivity of Saccharomyces cerevisiae to the cell-penetrating antifungal peptide PAF26 correlates with endogenous nitric oxide (NO) production.
abstract: PAF26 is a synthetic fungicidal hexapeptide with cell-penetration properties and non-lytic mode of action. We demonstrate herein the endogenous accumulation of reactive oxygen species (ROS) and nitric oxide (NO) in the model fungus Saccharomyces cerevisiae treated with PAF26. However, the S. cerevisiae deletion mutant of YAP1 - the major inductor of defense to oxidative stress - did not show high sensitivity to PAF26 but rather increased resistance, and its ROS accumulation did not differ from that of the parental strain. Cross-protection experiments suggest that the oxidant H(2)O(2) and PAF26 kill yeast through different pathways. Overall, the data indicate that ROS are not the primary antifungal mechanism of the peptide. On the contrary, the PAF26-induced intracellular production of NO was blocked in two distinct resistant mutants: the above mentioned Δyap1, which had the induction of NO disrupted, and the previously reported Δarg1 from the biosynthetic pathway of arginine, which has reduced basal NO levels. The NO synthase inhibitor l-NAME partially restored yeast growth in the presence of PAF26. These findings correlate antifungal activity of PAF26 with NO production and provide a plausible explanation for the resistance phenotype of Δarg1 through its involvement in NO biosynthesis.
authors: Departamento de Ciencia de los Alimentos, Instituto de Agroquímica y Tecnología de Alimentos (IATA)-CSIC, Valencia, Spain.
authors: Lourdes
authors: L
authors: Carmona
authors: Mónica
authors: M
authors: Gandía
authors: Belén
authors: B
authors: López-García
authors: Jose F
authors: JF
authors: Marcos
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D001119:Arginase / Q000235:genetics; D025141:Drug Resistance, Fungal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017353:Gene Deletion; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis*; D009842:Oligopeptides / Q000494:pharmacology*; D018384:Oxidative Stress / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
chemical_list: D000935:Antifungal Agents; D004791:Enzyme Inhibitors; D009842:Oligopeptides; C459185:PAF26 peptide; D017382:Reactive Oxygen Species; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C086677:YAP1 protein, S cerevisiae; D009569:Nitric Oxide; C544448:Arg1 protein, mouse; D001119:Arginase; D019331:NG-Nitroarginine Methyl Ester