Zinc surplus in yeast cells has been previously investigated thanks to transcriptomic studies by using traditionally Saccharomyces cerevisiae as a model. However, proteome response under zinc-replete conditions needs to be further studied in yeast. For that reason, eight yeast strains from seven different species were inoculated in zinc-depleted and zinc-replete media. The quantitative and qualitative comparative label-free proteomic analysis enabled the identification of between 2000 and 3000 proteins from each strain, and changes to the proteome ranged from 2.5% to 43.7% of identified proteins. Functional analysis (Blast2Go) has allowed the characterization of differentially abundant proteins. Common zinc-responsive proteins have been detected for the eight strains such as oxidoreductases and transferases (increased in abundance) although more of the changes detected were not shared by all the strains tested. Zinc distribution under replete conditions has been analysed in cell wall fractions, and cytoplasm plus organelles (intracellular fraction), with the latter identified to be the main zinc reservoir. Additionally, the energy dispersive spectroscopy coupled to the scanning electron microscopy technique has permitted the visualization of zinc in the whole cell. Proteomic analysis revealed that while there were some shared responses, the non-model yeast species also showed distinct proteomic profiles in zinc-replete conditions, compared to S. cerevisiae, revealing new zinc-responsive proteins in yeast.
© 2020 Society for Applied Microbiology and John Wiley & Sons Ltd.