title: Metabolic and regulatory changes associated with growth of Saccharomyces cerevisiae in 1.4 M NaCl. Evidence for osmotic induction of glycerol dissimilation via the dihydroxyacetone pathway.
abstract: The salt-instigated protein expression of Saccharomyces cerevisiae during growth in either 0.7 or 1.4 M NaCl was studied by two-dimensional polyacrylamide gel electrophoresis. The 73 protein spots that were identified as more than 3-fold responsive in 1.4 M NaCl were further grouped by response class (halometric, low-salt, and high-salt regulation). Roughly 40% of these responsive proteins were found to decrease in expression, while at higher magnitudes of change (>8-fold) only induction was recorded. Enolase 1 (Eno1p) was the most increasing protein by absolute numbers per cell, but not by -fold change, and the enzymes involved in glycerol synthesis, Gpd1p and Gpp2p, were also induced to a similar degree as Eno1p. We furthermore present evidence for salt induction of glycerol dissimilation via dihydroxyacetone and also identify genes putatively encoding the two enzymes involved; dihydroxyacetone kinase (DAK1 and DAK2) and glycerol dehydrogenase (YPR1 and GCY1). The GPD1, GPP2, GCY1, DAK1, and ENO1 genes all displayed a halometric increase in the amount of transcript. This increase was closely linked to the salt-induced rate of protein synthesis of the corresponding proteins, indicating mainly transcriptional regulation of expression for these genes. A consensus element with homology to the URS sequence of the ENO1 promoter was found in the promoters of the GPD1, GPP2, GCY1, and DAK1 genes.
authors.affiliation: Department of General and Marine Microbiology, Göteborg University, Medicinaregatan 9 C, 413 90 Göteborg, Sweden. joakim.Norbeck@gmm.gu.se
authors.forename: J
authors.initials: J
authors.lastname: Norbeck
authors.forename: A
authors.initials: A
authors.lastname: Blomberg
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D004098:Dihydroxyacetone / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D005990:Glycerol / Q000378:metabolism*; D007526:Isoelectric Point; D008956:Models, Chemical; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D010641:Phenotype; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development*; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000494:pharmacology*; D013401:Sugar Alcohol Dehydrogenases / Q000235:genetics / Q000378:metabolism
chemical_list: D012965:Sodium Chloride; D013401:Sugar Alcohol Dehydrogenases; C020672:glycerol dehydrogenase; D017853:Phosphotransferases (Alcohol Group Acceptor); C023132:glycerone kinase; D004098:Dihydroxyacetone; D005990:Glycerol