FIG 9.

Upc2A binds directly to ERG11, PDR1, and CDR1 promoter regions. (A) A wild-type (ATCC2001wt) strain was grown in the absence or presence of fluconazole (ATCC2001wt + Fluconazole), along with an isogenic upc2AΔ strain. Total sheared chromatin was prepared from all the strains and immunoprecipitated with anti-Upc2A polyclonal antibody. Immunoprecipitates were analyzed by qPCR using primers specific for the ERG11, PDR1, and CDR1 promoters as well as a region of the ERG11 coding sequence (CDS) as a negative control for enrichment. Percentages of enrichment were calculated by comparing the ratios of each PCR product produced using immunopurified chromatin to that produced in total chromatin. (B) A strain containing the camphor-off allele of ERG11 was grown in the presence or absence of camphor as indicated. Total chromatin was isolated, sheared, and then immunoprecipitated using the anti-Upc2A antibody. Percentages of enrichment of each PCR product were calculated as described for panel A. (C) Model for the coordinate control of ERG11, PDR1, and CDR1 transcription by Upc2A. Based on its striking sequence conservation with S. cerevisiae Upc2, we hypothesize that in the presence of ergosterol, the majority of Upc2A is excluded from the nucleus. Upon limitation of ergosterol, this inhibition is relieved, and Upc2A moves to the nucleus and activates target genes.