| Popis: |
SummaryPredatory interactions among microbes are considered to be a major evolutionary driving force for biodiversity and the defense against phagocytic killing. The fungivorous amoebaProtostelium aurantiumhas a wide fungal food spectrum but strongly discriminates among major pathogenic members of theSaccharomycotina. WhileC. albicansis not recognized,C. glabratais rapidly internalized, but remains undigested. Phagocytic killing and feeding byP. aurantiumis highly effective for the third major fungal pathogen,C. parapsilosis.Here we show that the different prey patterns of the three yeasts were reflected by distinct transcriptional responses, indicating fungal copper and redox homeostasis as primary targets during intracellular killing ofC. parapsilosis. Gene deletions in this fungus for the highly expressed copper exporter Crp1 and the peroxiredoxin Prx1 confirmed their role in copper and redox homeostasis, respectively and identified methionine biosynthesis as a ROS sensitive metabolic target during predation. Both, intact Cu export and redox homeostasis contributed to the survival ofC. parapsilosisnot only when encounteringP. aurantium, but also in the presence of human macrophages. As both genes were found to be widely conserved within the entireCandidaclade, our results suggest that they could be part of a basic tool-kit to survive phagocytic attacks by environmental predators. |
