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Ctt1 catalase activity potentiates antifungal azoles in the emerging opportunistic pathogen Saccharomyces cerevisiae
Fungi respond to antifungal drugs by increasing their antioxidant stress response. How this impacts antifungal efficacy remains controversial and not well understood. Here we examine the role of catalase activity in the resistance of Saccharomyces cerevisiae to the common antifungals, fluconazole an...
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Published in: | Scientific reports 2019-06, Vol.9 (1), p.9185-10, Article 9185 |
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Main Authors: | , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Fungi respond to antifungal drugs by increasing their antioxidant stress response. How this impacts antifungal efficacy remains controversial and not well understood. Here we examine the role of catalase activity in the resistance of
Saccharomyces cerevisiae
to the common antifungals, fluconazole and miconazole, for which we report minimum inhibitory concentrations (MICs) of 104 and 19 μM, respectively. At sub-MIC concentrations, fluconazole and miconazole stimulate catalase activity 2-3-fold but, unexpectedly, deletion of cytosolic catalase (
ctt1
) makes cells more resistant to these azoles and to clotrimazole, itraconazole and posaconazole. On the other hand, upregulating Ctt1 activity by preconditioning with 0.2 mM H
2
O
2
potentiates miconazole 32-fold and fluconazole 4-fold. Since H
2
O
2
preconditioning does not alter the resistance of
ctt1
Δ cells, which possess negligible catalase activity, we link azole potentiation with Ctt1 upregulation. In contrast,
sod2Δ
cells deleted for mitochondrial superoxide dismutase are 4–8-fold
more
azole sensitive than wild-type cells, revealing that Sod2 activity protects cells against azole toxicity. In fact, the
ctt1
Δ mutant has double the Sod2 activity of wild-type cells so
ctt1
deletion increases azole resistance in part by Sod2 upregulation. Notably, deletion of peroxisomal/mitochondrial
cta1
or cytosolic
sod1
does not alter fluconazole or miconazole potency. |
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ISSN: | 2045-2322 2045-2322 |
DOI: | 10.1038/s41598-019-45070-w |