Fcr1p Inhibits Development of Fluconazole Resistance in Candida albicans by Abolishing CDR1 Induction

Abstract

Overexpression of Candida drug resistance 1 (CDR1) gene in Candida albicans (C. albicans), an efflux pump, is one of the major mechanisms contributing to drug resistance. C. albicans for fluconazole resistance 1 protein (Fcr1p) is a member of the family of zinc cluster proteins homologous to Pdr1p and Pdr3p (pleiotropic drug resistance protein) mediating azole resistance in Saccharomyces cerevisiae (S. cerevisiae) by regulating the expression of pleiotropic drug resistance 5 (PDR5) homologous to C. albicans CDR1. A previous study has showed that for fluconazole resistance 1 (FCR1) could also confer azole resistance in S. cerevisiae pdr1 pdr3 mutant by regulating PDR5. Therefore, we investigated the role of FCR1 in the development of C. albicans azole resistance in vitro and in vivo. Our results showed that Fcr1p inhibited fluconazole (FLC) resistance development in C. albicans through abolishing the induction of CDR1 expression by FLC, and in contrast FLC resistance development was accelerated resulting from the deletion of FCR1.