Stimulation of the yeast high osmolarity glycerol (HOG) pathway: evidence for a signal generated by a change in turgor rather than by water stress.
The Saccharomyces cerevisiae HOG pathway controls responses to osmotic shock such as production of the osmolyte glycerol. Here we show that the HOG pathway can be stimulated by addition of glycerol. This stimulation was strongly diminished in cells expressing an unregulated Fps1p glycerol channel, presumably because glycerol rapidly equilibrated across the plasma membrane. Ethanol, which passes the plasma membrane readily and causes water stress by disturbing the hydration of biomolecules, did not activate the HOG pathway. These observations suggest that stimulation of the HOG pathway is mediated by a turgor change and not by water stress per se.
Tamás
M J
MJ
Laboratorium voor Moleculaire Celbiologie, Katholieke Universiteit Leuven, Kardinaal Mercierlaan 92, B-3001, Leuven-Heverlee, Belgium.
Rep
M
M
Thevelein
J M
JM
Hohmann
S
S
D015152:Blotting, Northern; D000431:Ethanol / Q000494:pharmacology; D005656:Fungal Proteins / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism* / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009994:Osmolar Concentration; D009997:Osmotic Pressure; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction; D012965:Sodium Chloride / Q000494:pharmacology
C093263:FPS1 protein, S cerevisiae; D005656:Fungal Proteins; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D000431:Ethanol; D012965:Sodium Chloride; C088589:HOG1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; D005990:Glycerol