Iron is an essential nutrient for virtually all living organisms and host iron availability plays a critical role in the host–pathogen relationship. Without effective mechanisms for acquisition, transport and utilization of iron, no organism especially parasites with high iron requirements, can survive. However, our knowledge about intracellular iron metabolism in eukaryotic pathogenic microorganisms is poor; it is not known, how iron is stored in the cell or how it is utilized. In the proposed project, we will investigate cytosolic iron metabolism in three unicellular eukaryotic pathogens: Candida albicans, Trichomonas vaginalis and Giardia intestinalis. We will use two different proteomic methods to identify proteins involved in iron metabolism: 1) 2D gel electrophoresis of cytosolic fractions from cells grown under iron-rich and iron-restricted conditions and 2) separation of 55Fe radiolabeled cytosolic iron complexes by liquid chromatography followed by native electrophoresis. Obtained proteins/protein complexes will be identified by Matrix-assisted laser desorption/ionization mass spectrometry and liquid chromatography-tandem mass spectrometry. We will test the cellular localization and the effect of the identified proteins on iron metabolism by overexpression in pathogens and yeast. The project has great potential to discover new mechanisms of iron metabolism as well as identify new therapeutic approaches for the treatment of human pathogens. This multidisciplinary project investigating different pathogenic organisms and using a broad range of state-of-the-art techniques and approaches will allow a young researcher with outstanding track record and potential to return to Europe, integrate into European scientific community, consolidate his research maturity and provide him with a strong background for establishing his own laboratory in later stages of his career.