Genes that function in stress response, morphogenesis, and membrane trafficking influence copper resistance.
(A) C. albicans strains were replica-plated onto minimal synthetic media containing copper or another indicated metal, and then the extent of growth was recorded and summarized in a heat map. The mutant strains clustered into three major groups. The sur7Δ mutant clustered with other mutants known to be defective in trafficking and morphogenesis, a separate cluster included the HOG1 pathway mutants that are sensitive to stress, and the known copper mutants crp1Δ and cup2Δ clustered. The results represent a compilation of three experiments for each metal performed on different days. (B) The sensitivity of sur7Δ to cadmium (Cd), chromium, (Cr), and cesium (Cs) was further tested by incubating cells in different concentrations of these metals in synthetic medium a 96-well plate, since replica-plating indicated some degree of growth inhibition in response to these metals. Results indicated that sur7Δ cells only showed strong sensitivity to copper. The graph represents the averages of two to three independent experiments performed on different days.