Identification and characterization of new transcription factors involved in response to systemic antifungals in Candida albicans

Abstract

Strategy : • serial dilutions assay on ATF-containing medium (5-fluorocytosine, 4 mg/L; amphotericin B, 1 mg/L; fluconazole, 2.5 mg/L; caspofungin, 0.1 mg/L) as well as on drug-free control plates (yeast extract-peptone-dextrose and synthetic complete medium) • comparison of growth capacity of each mutant after two days at 30°C to that of parental strains • first screen with all the mutants, second screen for phenotypes confirmation 1.Introduction Despite an extensive research to identify new cellular targets, only few antifungal drugs are available today. The systematic determination of the susceptibility of C. albicans transcription factor (TF) mutants to one drug of each of the four classes of systemic antifungals (ATF) may facilitate the discovery of molecules able to enhance the effects of already available ATF as well as the identification of new fungal-specific targets. The C. albicans genome contains approximatively 250 predicted TFs and more than 50 genes encoding proteins involved in general mechanisms of transcription. Among these 300 proteins, we obtained by four different disruption strategies 239 viable homozygous deletion mutants (Table 1). We determined the ATF susceptibility of these TF mutants and aimed at characterizing the function and identifying the target genes of theses TF.