Regulating Promoter Element of Iron-dependent Gene FRP1 in Candida albicans by Site-directed Mutation

Abstract:

Microarray analysis revealed that the expression of ferric reductase (FRP1) can be regulated by the Rim101 protein. In order to find new transcriptional regulatory element in the promoter of FRP1, we analyzed the 1000 bp sequence upstream of ATG to find 2 potential Rim101p binding sites. We generated site-specific mutations in each of the two sites and fused these mutated promoters to LacZ. Then the promoter-LacZ fusion construct was recombinant into wild type and rim101-/- strains for b- galactosidase assay. The results revealed that the FRP1 was up-regulated in alkaline pH and this was caused by iron starvation. The ?650 site, not the ?160 site, had an important role in FRP1 Rim101p-dependent expression. We conclude that Rim101p may interact with the ?650 binding site of the promoter to regulate the FRP1 expression.

Key words:site-directed mutation, Candida albicans, Rim101 protein, ferric reductase gene