Conserved fungal genes as potential targets for broad-spectrum antifungal drug discovery.
The discovery of novel classes of antifungal drugs depends to a certain extent on the identification of new, unexplored targets that are essential for growth of fungal pathogens. Likewise, the broad-spectrum capacity of future antifungals requires the target gene(s) to be conserved among key fungal pathogens. Using a genome comparison (or concordance) tool, we identified 240 conserved genes as candidates for potential antifungal targets in 10 fungal genomes. To facilitate the identification of essential genes in Candida albicans, we developed a repressible C. albicans MET3 (CaMET3) promoter system capable of evaluating gene essentiality on a genome-wide scale. The CaMET3 promoter was found to be highly amenable to controlled gene expression, a prerequisite for use in target-based whole-cell screening. When the expression of the known antifungal target C. albicans ERG1 was reduced via down-regulation of the CaMET3 promoter, the CaERG1 conditional mutant strain became hypersensitive, specifically to its inhibitor, terbinafine. Furthermore, parallel screening against a small compound library using the CaERG1 conditional mutant under normal and repressed conditions uncovered several hypersensitive compound hits. This work therefore demonstrates a streamlined process for proceeding from selection and validation of candidate antifungal targets to screening for specific inhibitors.
Liu
Mengping
M
Bristol-Myers Squibb Company Pharmaceutical Research Institute, 5 Research Parkway, Wallingford, CT 06492, USA.
Healy
Matthew D
MD
Dougherty
Brian A
BA
Esposito
Kim M
KM
Maurice
Trina C
TC
Mazzucco
Charles E
CE
Bruccoleri
Robert E
RE
Davison
Daniel B
DB
Frosco
Marybeth
M
Barrett
John F
JF
Wang
Ying-Kai
YK
D000935:Antifungal Agents / Q000494:pharmacology*; D001483:Base Sequence; D002176:Candida albicans / Q000187:drug effects / Q000235:genetics*; D019295:Computational Biology / Q000379:methods; D017124:Conserved Sequence; D015195:Drug Design; D005800:Genes, Fungal; D008826:Microbial Sensitivity Tests / Q000379:methods; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics*
D000935:Antifungal Agents