title: Genome-wide fitness test and mechanism-of-action studies of inhibitory compounds in Candida albicans.
abstract: Candida albicans is a prevalent fungal pathogen amongst the immunocompromised population, causing both superficial and life-threatening infections. Since C. albicans is diploid, classical transmission genetics can not be performed to study specific aspects of its biology and pathogenesis. Here, we exploit the diploid status of C. albicans by constructing a library of 2,868 heterozygous deletion mutants and screening this collection using 35 known or novel compounds to survey chemically induced haploinsufficiency in the pathogen. In this reverse genetic assay termed the fitness test, genes related to the mechanism of action of the probe compounds are clearly identified, supporting their functional roles and genetic interactions. In this report, chemical-genetic relationships are provided for multiple FDA-approved antifungal drugs (fluconazole, voriconazole, caspofungin, 5-fluorocytosine, and amphotericin B) as well as additional compounds targeting ergosterol, fatty acid and sphingolipid biosynthesis, microtubules, actin, secretion, rRNA processing, translation, glycosylation, and protein folding mechanisms. We also demonstrate how chemically induced haploinsufficiency profiles can be used to identify the mechanism of action of novel antifungal agents, thereby illustrating the potential utility of this approach to antifungal drug discovery.
authors.affiliation: Center of Fungal Genetics, Merck Frosst Canada Ltd., Montreal, Quebec, Canada.
authors.forename: Deming
authors.initials: D
authors.lastname: Xu
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.forename: Troy
authors.initials: T
authors.lastname: Ketela
authors.forename: Sebastien
authors.initials: S
authors.lastname: Lemieux
authors.forename: Karynn
authors.initials: K
authors.lastname: Veillette
authors.forename: Nick
authors.initials: N
authors.lastname: Martel
authors.forename: John
authors.initials: J
authors.lastname: Davison
authors.forename: Susan
authors.initials: S
authors.lastname: Sillaots
authors.forename: Steve
authors.initials: S
authors.lastname: Trosok
authors.forename: Catherine
authors.initials: C
authors.lastname: Bachewich
authors.forename: Howard
authors.initials: H
authors.lastname: Bussey
authors.forename: Phil
authors.initials: P
authors.lastname: Youngman
authors.forename: Terry
authors.initials: T
authors.lastname: Roemer
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D004271:DNA, Fungal / Q000032:analysis; D015195:Drug Design; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects*; D016681:Genome, Fungal; D008826:Microbial Sensitivity Tests; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D004271:DNA, Fungal; D012333:RNA, Messenger