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ABSTRACTResistance of Candida albicansto azole antifungal drugs is mediated by two types of efflux pumps, encoded by the MDR1gene and the CDRgene family. MDR1mRNA levels in a susceptible clinical isolate are induced by benomyl (BEN) but not by other drugs previously shown to induce MDR1. To monitor MDR1expression under several conditions, the MDR1promoter was fused to the Renilla reniformisluciferase reporter gene (RLUC). The promoter was monitored for its responses to four oxidizing agents, five toxic hydrophobic compounds, and an alkylating agent, all shown to induce major facilitator pumps in other organisms. Deletion constructs of the MDR1promoter were used to analyze the basal transcription of the promoter and its responses to the toxic compound BEN and the oxidizing agent tert-butyl hydrogen peroxide (T-BHP). The cis-acting elements in the MDR1promoter responsible for induction by BEN were localized between −399 and −299 upstream of the start codon. The cis-acting elements responsible for MDR1induction by T-BHP were localized between −601 and −500 upstream of the start codon. The T-BHP induction region contains a sequence that resembles the YAP1-responsive element (YRE) in Saccharomyces cerevisiae. This CandidaYRE was placed upstream of a noninducible promoter in the luciferase construct, resulting in an inducible promoter. Inversion or mutation of the 7-bp YRE eliminated induction. Many of the drugs used in this analysis induce the MDR1promoter at concentrations that inhibit cell growth. These analyses define cis-acting elements responsible for drug induction of the MDR1promoter.