The Role of the MAPK Pathways in Response to Ethanol Stress in Saccharomyces cerevisiae

Abstract

During fermentation process, yeast cells are often exposed to ethanol. Although the toxicity of ethanol to budding yeast Saccharomyces cerevisiae has widely been studied, the ethanol stress signaling is still unknown. The growth of the mutants lacking genes involved in the mitogen activated protein kinase (MAPK) pathways was examined under ethanol stress condition. Our results revealed that the STE3, and AKR1 genes involved in the pheromone signaling pathway, and the BCK1, MPK1, SWI4, SWI6, and MBP1 genes involved in the cell wall integrity pathway, were required for tolerance to ethanol. In addition to the mutants of the cell wall integrity pathway, the Δste3 and Δakr1 mutants were sensitive to a cell wall perturbing agent, calcoflour white, suggesting the role of these signaling molecules in maintaining cell wall during ethanol stress.