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Proteome of tolerance fine-tuning in the human pathogen black yeast Exophiala dermatitidis
- Tesei, Donatella, Marzban, Gorji, Marchetti-Deschmann, Martina, Tafer, Hakim, Arcalis, Elsa, Sterflinger, Katja
- Journal of proteomics 2015 v.128 pp. 39-57
- Exophiala dermatitidis, carbon, cold stress, dishwashers, drinking water, environmental factors, habitats, heat tolerance, hosts, humans, mass spectrometry, pathogenicity, pathogens, protein content, protein synthesis, proteins, proteome, stress response, temperature, yeasts
- The black yeast Exophiala dermatitidis is a worldwide distributed agent of primary and secondary diseases in both immunocompromised and healthy humans, with a high prevalence in human-made environments. Since thermo-tolerance has a crucial role in the fungus persistence in man-dominated habitat and in its pathogenicity, three incubation temperatures (37, 45, 1°C) and two time spans (1h, 1week) were selected to simulate different environmental conditions and to investigate the effect of temperature on the proteome of E. dermatitidis CBS 525.76. Using a novel protocol for protein extraction from black yeasts, 2-D DIGE could be applied for characterization of changes in total protein spot abundance among the experimental conditions. A total of 32 variable proteins were identified by mass spectrometry. Data about protein functions, localization and pathways were also obtained. A typical stress response under non-optimal temperature could not be observed at the proteome level, whereas a reduction of the metabolic activity, mostly concerning processes as the general carbon metabolism, was detected after exposure to cold. These results suggest that a fine protein modulation takes place following temperature treatment and a repertoire of stable protein might be at the base of E. dermatitidis adaptation to altered growth conditions.E. dermatitidis is a pathogenic black yeast causing neurotropic infections, systemic and subcutaneous disease in a wide range of hosts, including humans. The discovery of the fungus high prevalence in man-made habitats, including sauna facilities, drinking water and dishwashers, generated concern and raised questions about the infection route. In the present work — which is the first contribution on E. dermatitidis proteome — the effect of different temperature conditions on the fungus protein pattern have been analyzed by using a gel-based approach and the temperature responsive proteins have been identified.The absence of a typical stress response following the exposure to non-optimal temperature was detected at the proteome level, along with a general reduction of the metabolic activity after exposure to cold. These results suggest that a very fine regulation of the protein expression as well as adaptations involving a basic set of stable proteins may be at the base of E. dermatitidis enormous ecological plasticity, which plays a role in the fungus distribution, also enabling the transition from natural to human habitat and to the human host.