Search for protein kinase(s) related to cell growth or viability maintenance in the presence of ethanol in budding and fission yeasts.

The article focuses on identifying protein kinases (PKs) involved in two distinct phases of alcohol fermentation in yeast: phase 1, characterized by yeast cell proliferation at low ethanol concentrations (Alcohol Growth Ability, AGA), and phase 2, marked by viability maintenance under high ethanol concentrations (Alcohol Viability, ALV). Using gene deletion screening in both budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe), the study found that different sets of PKs regulate these phases, with only a few AGA-related PKs conserved between the two species. Notably, Bub1 kinase was important for proliferation in low ethanol but not for viability in high ethanol, and no homologous PKs were shared between the yeasts for ALV, suggesting distinct mechanisms govern ethanol tolerance during growth and survival phases. These findings contribute to understanding yeast adaptation to ethanol stress, relevant for fermentation processes such as sake brewing.