Open AccessIdentification of a Copper-Inducible Promoter for Use in Ectopic Expression in the Fungal Pathogen Histoplasma capsulatum
Author(s) -
Dana Gebhart,
Adam K. Bahrami,
Anita Sil
Publication year - 2006
Publication title -
eukaryotic cell
Language(s) - English
Resource type - Journals
eISSN - 1535-9778
pISSN - 1535-9786
DOI - 10.1128/ec.00028-06
Subject(s) - biology , ectopic expression , gene , gene expression , microarray analysis techniques , promoter , heterologous expression , reporter gene , regulation of gene expression , genetics , gene silencing , dna microarray , microbiology and biotechnology , recombinant dna
Despite the existence of a number of genetic tools to study the fungal pathogenHistoplasma capsulatum , strategies for conditional gene expression have not been developed. We used microarray analysis to identify genes that are transcriptionally induced or repressed by the addition of copper sulfate (CuSO4 ) toH. capsulatum yeast cultures. One of these genes,CRP1 , encodes a putative copper efflux pump that is significantly induced in the presence of CuSO4 . The upstream regulatory region ofCRP1 was sufficient to drive copper-regulated expression of two reporter genes,lacZ and the gene encoding green fluorescent protein. Microarray experiments were performed to determine a copper concentration that triggers accumulation of theCRP1 transcript without significant perturbation of global gene expression. These studies show that theCRP1 upstream regulatory region can be used for ectopic expression of heterologous genes inH. capsulatum . Furthermore, they demonstrate the strategic use of microarrays to identify conditional promoters that confer induction in the absence of large-scale shifts in gene expression.