Eukaryotic translation factor eIF5A contributes to acetic acid tolerance in Saccharomyces cerevisiae via transcriptional factor Ume6p

Abstract

Background Saccharomyces cerevisiae is well-known as an ideal model system for basic research and important industrial microorganism for biotechnological applications. Acetic acid is an important growth inhibitor that has deleterious effects on both the growth and fermentation performance of yeast cells. Comprehensive understanding of the mechanisms underlying S. cerevisiae adaptive response to acetic acid is always a focus and indispensable for development of robust industrial strains. eIF5A is a specific translation factor that is especially required for the formation of peptide bond between certain residues including proline regarded as poor substrates for slow peptide bond formation. Decrease of eIF5A activity resulted in temperature-sensitive phenotype of yeast, while up-regulation of eIF5A protected transgenic Arabidopsis against high temperature, oxidative or osmotic stress. However, the exact roles and functional mechanisms of eIF5A in stress response are as yet largely unknown. Results In this research, we compared cell growth between the eIF5A overexpressing and the control S. cerevisiae strains under various stressed conditions. Improvement of acetic acid tolerance by enhanced eIF5A activity was observed all in spot assay, growth profiles and survival assay. eIF5A prompts the synthesis of Ume6p, a pleiotropic transcriptional factor containing polyproline motifs, mainly in a translational related way. As a consequence, BEM4, BUD21 and IME4, the direct targets of Ume6p, were up-regulated in eIF5A overexpressing strain, especially under acetic acid stress. Overexpression of UME6 results in similar profiles of cell growth and target genes transcription to eIF5A overexpression, confirming the role of Ume6p and its association between eIF5A and acetic acid tolerance. Conclusion Translation factor eIF5A protects yeast cells against acetic acid challenge by the eIF5A-Ume6p-Bud21p/Ime4p/Bem4p axles, which provides new insights into the molecular mechanisms underlying the adaptive response and tolerance to acetic acid in S. cerevisiae and novel targets for construction of robust industrial strains.

Identification of acetic acid sensitive strains through biosensor-based screening of a Saccharomyces cerevisiae CRISPRi library

“…Moreover, Cheng et al . [ 86 ] has showed that another initiation factor (eIF5A) plays part in acetic acid tolerance regulation. They demonstrated that the eIF5A-Ume6 switch regulates tolerance to acetic acid in several ways.…”

Engineering of cis-Element in Saccharomyces cerevisiae for Efficient Accumulation of Value-Added Compound Squalene via Downregulation of the Downstream Metabolic Flux

“…Plasmid pFA6a-kanMX4 was used as the donor of G418-resistant cassette KanMX. To compare the promoter strength by using the green fluorescence protein (GFP) as the reporter, plasmid pYC-GA 30 was applied to construct gfp5 expression cassettes with various promoters. For scarless manipulation of genome, the YEp352-derived plasmid pGMZC was constructed by ligation of the galactose-induced GAL1 promoter with DNA fragment mazF-zeoR covering mazF-T AOX1 and P TEF1 -zeoR-T CYC1 from plasmid pEBCMMZC.…”

Human Nucleolar Protein 7 (NOL7) is required for pre-rRNA transcription and pre-18S rRNA processing

“…UV-crosslinked membranes were stained with methylene blue (0.025% w/v) and imaged. Blots were hybridized to 32 P radiolabeled DNA oligonucleotide probes (5'ETS 5'-CCTCTCCAGCGACAGGTCGCCAGAGGACAGCGTGTCAGC-3') or (P3 (ITS1) 5'-AAGGGGTCTTTAAACCTCCGCGCCGGAACGCGCTAGGTAC-3') and detected by phosphorimager (Amersham™ Typhoon™, 29187194). Images were analyzed using ImageJ, ratio-analysis of multiple precursors (RAMP) was performed 17 .…”

“…Bud21 is also known to be a Ty1 retrotransposon host factor 29 . Deletion of Bud21 renders increased hypoxia tolerance 30 and improved xylose carbon source utilization 31 , while Bud21 expression is upregulated upon acetic acid challenge 32 .…”

“…Bud21 is also known to be a Ty1 retrotransposon host factor 29 . Deletion of Bud21 renders increased hypoxia tolerance 30 and improved xylose carbon source utilization 31 , while Bud21 expression is upregulated upon acetic acid challenge 32 . Overall, not much is known about the molecular functions of Utp9 and Bud21 in ribosome biogenesis, even in the well-studied model organism S. cerevisiae .…”