The Saccharomyces cerevisiae deletion collection was screened for impaired growth on glucose-based complex medium containing 6% ethanol. Forty-six mutants were found. Genes encoding proteins involved in vacuolar function, the cell integrity pathway, mitochondrial function, subunits of the co-chaperone complex GimC and components of the SAGA transcription factor complex were in this way found to be important for the growth of wild-type Saccharomyces yeast in the presence of ethanol. Several mutants were also sensitive to Calcofluor white (14 mutants), sorbic acid (9), increased temperature (5) and NaCl (3). The transcription factors Msn2p and Ars1p, tagged with green fluorescent protein, were translocated to the nucleus upon ethanol stress. Only one of the genes that contain STRE elements in the promoter was important under ethanol stress; this was TPS1, encoding trehalose 6-phosphate synthase. The map kinase of the cell integrity pathway, Slt2p, was phosphorylated when cells were treated with 6% ethanol. Two out of three mutants tested fermented 20% glucose more slowly than the wild-type.
Copyright 2006 John Wiley & Sons, Ltd.