Rpn4- and Proteasome- Mediated Yeast Response to Ethanol Stress: a View from a Proteome

ABSTRACT: Distilled spirits production using S. cerevisiae requires understanding the mechanisms of yeast cell response to the alcohol stress. Reportedly, specific mutations in genes of the ubiquitin-proteasome system, e.g. RPN4, may result in strains exhibiting either hyper-resistance or increased sensitivity to different alcohols. In this work, we studied Rpn4-dependent response of different yeast strains to short-term ethanol exposure. Three S. cerevisiae strains were used: wild-type (WT), mutant strain with RPN4 gene deletion (rpn4-delta), and mutant strain with decreased proteasome activity due to PRE1 deregulation (YPL). The resistance tests demonstrated an increased sensitivity of mutant strains to ethanol compared with WT. Comparative proteomics analysis revealed significant differences in molecular responses to ethanol between different strains. GO analysis of proteins upregulated in WT showed enrichments represented by oxidative and heat responses, protein folding/unfolding and protein degradation. Enrichment of at least one of these responses was not observed in mutant strains. At the same time, trehalose synthesis and accumulation of stress granules were enhanced in the mutant strains. We suggest that these pathways could partially compensate for the failure of ubiquitin-proteasome system to cope with the ethanol stress. Also, we suggest impaired compensatory activation of autophagic degradation system in rpn4-delta strain and propose that Rpn4 can be a regulator for autophagy upon ethanol stress. These findings can be a basis for creating genetically modified yeast strains resistant to high levels of alcohol, being further used for fermentation in ethanol production.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Saccharomyces Cerevisiae (baker's Yeast)

SUBMITTER: julia Bubis  

LAB HEAD: Mikhail Gorshkov

PROVIDER: PXD014236 | Pride | 2020-04-22

REPOSITORIES: Pride