Differential distribution and proteomic response of Saccharomyces cerevisiae and non-model yeast species to zinc.

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, 8 yeast strains from 7 different species were inoculated in zinc-depleted and zinc-replete media. Quantitative and qualitative comparative label-free proteomic analysis enabled the identification of between 2000-3000 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 characterisation of differentially abundant proteins. Common zinc-responsive proteins have been detected for the 8 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, SEM-EDS 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 This article is protected by copyright. All rights reserved.