Expression of the Glyoxalase I Gene of Saccharomyces cerevisiae Is Regulated by High Osmolarity Glycerol Mitogen-activated Protein Kinase Pathway in Osmotic Stress Response
Methylglyoxal is a cytotoxic metabolite derived from dihydroxyacetone phosphate, an intermediate of glycolysis. Detoxification of methylglyoxal is performed by glyoxalase I. Expression of the structural gene of glyoxalase I (GLO1) of Saccharomyces cerevisiae under several stress conditions was investigated using the GLO1-lacZ fusion gene, and expression of the GLO1 gene was found to be specifically induced by osmotic stress. The Hog1p is one of the mitogen-activated protein kinases (MAPKs) in S. cerevisiae, and both Msn2p and Msn4p are the transcriptional regulators that are thought to be under the control of Hog1p-MAPK. Expression of the GLO1gene under osmotic stress was completely repressed inhog1Δ disruptant and was repressed approximately 80 and 50% in msn2Δ and msn4Δ disruptants, respectively. A double mutant of the MSN2 and MSN4 gene was unable to induce expression of the GLO1 gene under highly osmotic conditions. Glucose consumption increased approximately 30% during the adaptive period in osmotic stress in the wild type strain. On the contrary, it was reduced by 15% in the hog1Δ mutant. When the yeast cell is exposed to highly osmotic conditions, glycerol is synthesized as a compatible solute. Glycerol is synthesized from glucose, and a rate-limiting enzyme in glycerol biosynthesis is glycerol-3-phosphate dehydrogenase (GPD1 gene product), which catalyzes reduction of dihydroxyacetone phosphate to glycerol 3-phosphate. Expression of the GPD1 gene is also under the control of Hog1p-MAPK. Methylglyoxal is also synthesized from dihydroxyacetone phosphate; therefore, induction of the GLO1 gene expression by osmotic stress was thought to scavenge methylglyoxal, which increased during glycerol production for adaptation to osmotic stress. Methylglyoxal is a cytotoxic metabolite derived from dihydroxyacetone phosphate, an intermediate of glycolysis. Detoxification of methylglyoxal is performed by glyoxalase I. Expression of the structural gene of glyoxalase I (GLO1) of Saccharomyces cerevisiae under several stress conditions was investigated using the GLO1-lacZ fusion gene, and expression of the GLO1 gene was found to be specifically induced by osmotic stress. The Hog1p is one of the mitogen-activated protein kinases (MAPKs) in S. cerevisiae, and both Msn2p and Msn4p are the transcriptional regulators that are thought to be under the control of Hog1p-MAPK. Expression of the GLO1gene under osmotic stress was completely repressed inhog1Δ disruptant and was repressed approximately 80 and 50% in msn2Δ and msn4Δ disruptants, respectively. A double mutant of the MSN2 and MSN4 gene was unable to induce expression of the GLO1 gene under highly osmotic conditions. Glucose consumption increased approximately 30% during the adaptive period in osmotic stress in the wild type strain. On the contrary, it was reduced by 15% in the hog1Δ mutant. When the yeast cell is exposed to highly osmotic conditions, glycerol is synthesized as a compatible solute. Glycerol is synthesized from glucose, and a rate-limiting enzyme in glycerol biosynthesis is glycerol-3-phosphate dehydrogenase (GPD1 gene product), which catalyzes reduction of dihydroxyacetone phosphate to glycerol 3-phosphate. Expression of the GPD1 gene is also under the control of Hog1p-MAPK. Methylglyoxal is also synthesized from dihydroxyacetone phosphate; therefore, induction of the GLO1 gene expression by osmotic stress was thought to scavenge methylglyoxal, which increased during glycerol production for adaptation to osmotic stress. Several environmental stresses are known to trigger intracellular alterations in organisms; e.g. synthesis of some stress-inducible proteins or the cellular responses against extracellular signals. Organisms of all types show the synthesis of stress-inducible proteins, and the most advanced understandings of the stress-inducible proteins have been obtained from the study of heat shock protein (HSP). 1The abbreviations used are: HSP, heat shock protein; HOG, high osmolarity glycerol; MAPK, mitogen-activated protein kinase; MAPKK, MAPK kinase; STRE, stress response element; bp, base pairs; SOD, superoxide dismutase. A sudden increase in the temperature of the environments in which cells are growing induces increased synthesis of a set of heat shock mRNAs and proteins in the cells. Heat shock response in eukaryotes is different from that in bacterial cells, although the basic mechanisms are similar among eukaryotes. A heat shock transcription factor, which is synthesized constitutively, is trimerized, modified, and translocated by heat shock and binds to a cis-element (the heat shock element) in the promoter region of HSP genes to activate transcription (for review, see Ref. 1Morimoto R.I. Tissieres A. Georgopoulos C. The Biology of Heat Shock Proteins and Molecular Chaperones. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY1994Google Scholar). Some HSPgenes in Saccharomyces cerevisiae, such asHSP104, HSP26, and HSP12, have anothercis-element, termed stress response element (STRE) (5′-AGGGG-3′), in addition to the heat shock element (2Schuller C. Brewster J.L. Alexander M.R. Gustin M.C. Ruis H. EMBO J. 1994; 13: 4382-4389Crossref PubMed Scopus (442) Google Scholar, 3Ruis H. Schuller C. BioEssays. 1995; 17: 959-965Crossref PubMed Scopus (359) Google Scholar). In addition to these HSP genes in S. cerevisiae, the CTT1 gene encoding cytosolic catalase has also been known to have the STRE in its 5′-flanking region (4Marchler G. Schuller C. Adam G. Ruis H. EMBO J. 1993; 12: 1997-2003Crossref PubMed Scopus (413) Google Scholar). Expression of the CTT1 gene is induced by a wide variety of stresses, such as osmotic stress and oxidative stress, as well as heat shock, and these stress signals are thought to be focusing on the STRE (2Schuller C. Brewster J.L. Alexander M.R. Gustin M.C. Ruis H. EMBO J. 1994; 13: 4382-4389Crossref PubMed Scopus (442) Google Scholar). Stress response mechanisms through the STRE are fairy broad; therefore, elucidation of molecular mechanisms for stress response, including screening an appropriate specific marker gene, is of considerable interest. In addition to heat shock response, one of the well-known stress response systems in S. cerevisiae is an osmotic stress response (5Burg M.B. Kwon E.D. Kultz D. FASEB J. 1996; 10: 1598-1606Crossref PubMed Scopus (159) Google Scholar, 6Mager W.H. Varela J.C.S. Mol. Microbiol. 1993; 10: 253-258Crossref PubMed Scopus (92) Google Scholar, 7Varela J.C.S. Mager W. Microbiology. 1996; 142: 721-731Crossref PubMed Scopus (51) Google Scholar). Increased osmolarity of environment surrounding the cells induces rapid increase in expression of various kinds of genes. The osmosensing system has been extensively studied in a bacterial system, and existence of a two-component regulatory system was proved (8Forst S.A. Roverts D.I. Res. Microbiol. 1994; 145: 363-374Crossref PubMed Scopus (113) Google Scholar, 9Pratt L.A. Silhavy T.J. Hoch J.A. Silhavy T.J. Two-Component Signal Transduction. American Society for Microbiology, Washington, D. C.1995: 105-127Google Scholar). S. cerevisiae also has a bacterial-like two-component osmosensing system consisted of Sln1p and Ssk1p (10Maeda T. Takekawa M. Saito H. Science. 1995; 269: 554-558Crossref PubMed Scopus (561) Google Scholar, 11Maeda T. Wurgler-Murphy S.M. Saito H. Nature. 1994; 369: 242-245Crossref PubMed Scopus (942) Google Scholar, 12Ota I.M. Varshavsky A. Science. 1993; 262: 566-569Crossref PubMed Scopus (367) Google Scholar, 13Posas F. Wurgler-Murphy S.M. Maeda T. Witten E.A. Thai T.C. Saito H. Cell. 1996; 86: 865-875Abstract Full Text Full Text PDF PubMed Scopus (747) Google Scholar). When the yeast cell is exposed to a highly osmotic environment, rapid efflux of water from the cell shrinks cell and decreases its turgor pressure. As one of adaptive responses to the osmotic stress, the yeast cell produces glycerol as a compatible osmolyte. A key enzyme in biosynthesis of glycerol is glycerol-3-phosphate dehydrogenase, which is encoded by the GPD1 gene. The GPD1 gene is essential for survival under highly osmotic conditions (14Albertyn J. Hohmann S. Thevelein J.M. Prior B.A. Mol. Cell. Biol. 1994; 14: 4135-4144Crossref PubMed Scopus (611) Google Scholar). Expression of the GPD1 gene under highly osmotic conditions is under the control of Hog1p (14Albertyn J. Hohmann S. Thevelein J.M. Prior B.A. Mol. Cell. Biol. 1994; 14: 4135-4144Crossref PubMed Scopus (611) Google Scholar). Hog1p is one of the mitogen-activated protein kinases (MAPKs) in S. cerevisiae. Both residues of Thr174 and Tyr176 of the Hog1p are phosphorylated by a MAPK kinase (MAPKK), Pbs2p. Pbs2p is phosphorylated by redundant MAPKK kinases, Ssk2p and Ssk22p. The hog1Δ knockout mutant showed lethality under highly osmotic conditions (2Schuller C. Brewster J.L. Alexander M.R. Gustin M.C. Ruis H. EMBO J. 1994; 13: 4382-4389Crossref PubMed Scopus (442) Google Scholar, 15Brewster J.L. de Valoir T. Dwyer N.D. Winter E. Gustin M.C. Science. 1993; 259: 1760-1763Crossref PubMed Scopus (1035) Google Scholar). The substrate for glycerol-3-phosphate dehydrogenase (Gpd1p) is dihydroxyacetone phosphate, an intermediate of glycolytic pathway, and the enzyme catalyzes reduction of dihydroxyacetone phosphate to glycerol 3-phosphate in the presence of NADH. Some phosphatases, such as Gpp2p, hydrolyze glycerol 3-phosphate to glycerol (16Norbeck J. Pahlman A.-K. Akhtar N. Blomberg A. Adler L. J. Biol. Chem. 1996; 271: 13875-13881Abstract Full Text Full Text PDF PubMed Scopus (190) Google Scholar). Dihydroxyacetone phosphate is also a substrate for methylglyoxal synthase that converts dihydroxyacetone phosphate to methylglyoxal (17Hopper D.J. Cooper R.A. Biochem. J. 1972; 128: 321-329Crossref PubMed Scopus (92) Google Scholar, 18Cooper R.A. Eur. J. Biochem. 1974; 44: 81-86Crossref PubMed Scopus Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar, S. M. J. Biol. Chem. Full Text PDF PubMed Google Scholar). Methylglyoxal is also synthesized during the PubMed Scopus Google Scholar, PubMed Scopus (190) Google Scholar). Methylglyoxal is a in and it has and Methylglyoxal various in cells, such as and to L.A. J. Biol. Chem. Full Text PDF PubMed Google Scholar, H. PubMed Scopus Google and it of methylglyoxal, the cells from to eukaryotes have several The glyoxalase system is a system for The glyoxalase system consisted of glyoxalase I which converts methylglyoxal to in the presence of and glyoxalase which to and have been the glyoxalase system in various and have proved that glyoxalase I is for of methylglyoxal A. Microbiol. 1995; PubMed Scopus Google A. J. Biol. Chem. 1996; 271: Full Text Full Text PDF PubMed Scopus Google Scholar). found that the GLO1 gene in its 5′-flanking and expression of the GLO1 gene was specifically induced by osmotic stress. In also expression of the GLO1 gene in several gene disruptants, the gene of which are in the osmolarity kinase pathway, and the GLO1 gene is under highly osmotic conditions. The S. cerevisiae used in study are in I. for of MSN2 gene F. M. Mol. Cell. Biol. 1993; 13: PubMed Scopus Google A. J.A. M. J.L. J. Biol. Chem. 1993; Full Text PDF PubMed Google and gene S. PubMed Scopus Google by F. of W. S. of and respectively. D. T. Mol. 1994; PubMed Scopus Google was by T. used in of or a a S. A. Biochem. J. 1996; PubMed Scopus Google a a a a a a study in a the GLO1-lacZ fusion gene, to the 5′-flanking region of the GLO1 gene and residues from The used and Both to the by A using these was and to of which the gene of its promoter region and J. PubMed Scopus Google Scholar). The was and the GLO1-lacZ was to the of the PubMed Google to The gene its and was by using and Both to for for and for these are by The was the and of to the was and and a in the of the gene was the gene to The was and and the was to S. cerevisiae S. A. Biochem. J. 1996; PubMed Scopus Google to the The of was using a as by and F. M. Mol. Cell. Biol. 1993; 13: PubMed Scopus Google and the disruptant was The MSN4 gene was by using and to the region and from the and the to the region and from the of the MSN4 gene. The was and and the and of The was and to the which the of Msn4p F. M. Mol. Cell. Biol. 1993; 13: PubMed Scopus Google and the gene to The was and and the the was to and to and and respectively. the GLO1 gene was as A the GLO1 gene, A. J. Biol. Chem. 1996; 271: Full Text Full Text PDF PubMed Scopus Google was and the GLO1 gene was to the of to The was and to the the of the GLO1 gene, and it was the gene to The was and the was to The was by using the S. PubMed Scopus Google and as a The double mutant of the and GLO1 genes was The disruptant was by the gene of using A. J.A. M. J.L. J. Biol. Chem. 1993; Full Text PDF PubMed Google Scholar). of gene was by or and of yeast was as in A. J. Biol. Chem. 1996; 271: Full Text Full Text PDF PubMed Scopus Google Scholar). A the gene D. T. Mol. 1994; PubMed Scopus Google was and and the the gene was to the of a The was S. cerevisiae of the gene was by the on glucose, yeast as by E. M. PubMed Scopus Google Scholar). of S. was in a of appropriate and for A of the was to a of glucose, yeast and for approximately When the of the approximately several such as and and was for heat shock the the was to an to and was for stress cells and cell as by for and in of phosphate to an an approximately of and a for for and used as cell I was as A. J. Biochem. PubMed Scopus Google Scholar). of the was as the of enzyme of was to the of H. F. 1974; PubMed Scopus Google Scholar). of the was as the of enzyme of was as by in Molecular Cold Spring Harbor Laboratory, Cold Spring Harbor, Scholar). of the was as the of enzyme by was by the of Biochem. PubMed Scopus Google Scholar). of S. cerevisiae in approximately and was was to the of Res. PubMed Scopus Google Scholar). the of the synthesized protein for expression of the GLO1 gene in osmotic stress response, cells for the addition of was by an as by J. T. Molecular A Cold Spring Harbor Laboratory, Cold Spring Harbor, Scholar). The GLO1 was by and the the of the GLO1 gene was by the and by using a of and in a of approximately and was to the of the to of was and the and of the using a of cell was as that cells in water of phosphate used as a of methylglyoxal in glyoxalase I The phosphate glyoxalase I and various of methylglyoxal, or cell Methylglyoxal and glyoxalase I was from was obtained from and the from and obtained from The was from was from is one of the transcriptional regulators in S. cerevisiae, and it as well as Mol. Cell. Biol. 1994; 14: PubMed Google Scholar, Mol. Microbiol. 1996; PubMed Scopus Google Scholar, N. PubMed Scopus Google Scholar, D.J. J. Biol. Chem. 1996; 271: Full Text Full Text PDF PubMed Scopus Google Scholar, D.J. J. Biol. Chem. 1994; 269: Full Text PDF PubMed Google Scholar). of methylglyoxal is performed by glyoxalase I in the presence of that expression of the GLO1 gene be by the both of the and disruptant and the glyoxalase I glyoxalase I was by the of the gene protein; protein; an of the 5′-flanking region of the GLO1 gene, found and of the Several genes have been to have the STRE, such as HSP26, and and expression of such genes is induced by several stresses, such as heat shock, oxidative stress, osmotic stress, stress, and on (2Schuller C. Brewster J.L. Alexander M.R. Gustin M.C. Ruis H. EMBO J. 1994; 13: 4382-4389Crossref PubMed Scopus (442) Google Scholar). The CTT1 gene cytosolic and it was used as a marker gene for for stress response through therefore, also used CTT1 catalase as a S. cerevisiae has catalase in that is encoded by the gene G. W. Ruis H. Eur. J. Biochem. PubMed Scopus Google the gene to specifically the CTT1 catalase The GLO1-lacZ fusion gene was also to the expression of GLO1 gene under several environmental As in expression of GLO1-lacZ was specifically induced by and stresses that induce expression of the CTT1 gene for induction of GLO1-lacZ I was also increased the cells although stresses the enzyme As in expression of GLO1-lacZ was induced by also by osmotic stresses, including induction of GLO1-lacZ expression under high was thought to be by osmotic stress of several stresses on expression of GLO1-lacZ fusion gene. cells of S. cerevisiae in approximately and and to the the heat shock a the was to an to for and cell as in the and CTT1 catalase and S. cerevisiae was in approximately and and to the for and cell as in the CTT1 catalase showed the of of for induction of GLO1-lacZ and of both gene expression was the of and induction of GLO1-lacZ was that of CTT1 was induction was in both genes. that an increase of from the GLO1-lacZ fusion gene was to the increased expression of the GLO1 gene, was the of for induction of GLO1-lacZ was S. cerevisiae was and the of the GLO1 gene was As in the increased by osmotic stress. increased of from GLO1-lacZ by osmotic stress was to the expression of GLO1 gene. de synthesis of some is for induction of the GLO1 gene the cells to protein synthesis and exposed to osmotic stress. As in of the GLO1 gene was also protein synthesis was induction of GLO1 gene expression was the synthesized during osmotic stress S. cerevisiae has been to have a two-component system for high osmolarity of Sln1p and Ssk1p a kinase for high osmolarity and a to the to the redundant MAPKK kinases Ssk2p and Ssk22p. MAPKK kinases the Pbs2p The Pbs2p also a high osmolarity from the The Pbs2p Hog1p-MAPK. in both signals on The proteins Msn2p and Msn4p are thought to be under the control of Hog1p in osmotic stress and both MSN2 and MSN4 genes by gene in the and expression of the GLO1 and CTT1 genes under highly osmotic conditions. As in induction of the GLO1 gene expression under highly osmotic conditions was completely repressed in the hog1Δ mutant In the msn2Δ mutant induction was approximately the wild type MSN2 On the the msn4Δ mutant induce approximately 50% expression of the GLO1 gene In the of double mutant of the MSN2 and MSN4 genes induction of GLO1 expression was that expression of the GLO1 gene under highly osmotic conditions is by the On the expression of the CTT1 gene was different from that of the GLO1gene In the induction of the CTT1 gene expression under highly osmotic conditions was reduced that of although the CTT1 was induced by osmotic stress. In the and the CTT1 gene expression was also induced as in the of the most was in the of the msn2Δ msn4Δ double mutant The CTT1 gene was induced in the the cells exposed to high osmotic stress. S. cerevisiae glycerol as a compatible the cells are exposed to highly osmotic Glycerol is synthesized from through dihydroxyacetone phosphate and glycerol 3-phosphate. On the methylglyoxal is also synthesized from dihydroxyacetone phosphate by methylglyoxal synthase (17Hopper D.J. Cooper R.A. Biochem. J. 1972; 128: 321-329Crossref PubMed Scopus (92) Google Scholar, 18Cooper R.A. Eur. J. Biochem. 1974; 44: 81-86Crossref PubMed Scopus Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar, S. M. J. Biol. Chem. Full Text PDF PubMed Google or from PubMed Scopus Google Scholar, PubMed Scopus (190) Google during of consumption is to be increased to glycerol during the adaptive response to highly osmotic the of in to the consumption of by yeast cells. When the cells exposed to highly osmotic conditions, intracellular water efflux was and it in cell the the increased A and it during the adaptation period and was The of the osmotic stress was it increased to from cell In the of osmotic stress during the period was similar to that of On the the cells exposed to high during the period increased to the yeast cells to the cell to osmotic pressure. Glucose consumption of under the osmotic conditions during the period was approximately 30% that during the period osmotic stress of the consumption of under highly osmotic conditions was that of the during the In the of hog1Δ mutant the consumption during the period was approximately 15% under highly osmotic conditions that in the in The consumption of the hog1Δ cells or by during the period was similar investigated intracellular of methylglyoxal increased the cells exposed to highly osmotic Methylglyoxal to Biochem. 1993; PubMed Scopus Google and the is the substrate for glyoxalase glyoxalase I catalyzes of it has been thought that methylglyoxal in the cell A. Microbiol. 1995; PubMed Scopus Google Scholar). methylglyoxal is it is by glyoxalase I A. J. Biol. Chem. 1996; 271: Full Text Full Text PDF PubMed Scopus Google Scholar). and GLO1 genes to of The mutant all S. PubMed Scopus Google and glyoxalase I was from the cell A. J. Biol. Chem. 1996; 271: Full Text Full Text PDF PubMed Scopus Google Scholar). The of methylglyoxal in the cell by was that in the cells for was increase of intracellular methylglyoxal was similar to that of consumption osmotic stress. methylglyoxal in the wild type using the that in was to rapid of methylglyoxal by the of and The gene is a transcriptional A key enzyme for biosynthesis is the gene and expression of the gene is by the is also for cells to the intracellular and the gene encoding is also under the control of is in the glyoxalase I of yeast cells to against such as N. Eur. J. Biochem. PubMed Scopus Google M. J. PubMed Scopus Google E. M. PubMed Scopus Google A. J.A. M. J.L. J. Biol. Chem. 1993; Full Text PDF PubMed Google and D. T. Mol. 1994; PubMed Scopus Google Scholar). methylglyoxal is a cytotoxic in the thought that expression of the GLO1 gene also be by alterations of glyoxalase I in the yeast cells the gene or in the mutant. On the found in the 5′-flanking region of the GLO1 gene, and expression of the GLO1 gene was specifically induced the cells exposed to highly osmotic and N. G. EMBO J. 1994; 13: PubMed Scopus Google that the gene encoding phosphate the in its promoter and expression of the gene was induced by several stresses, such as heat shock, osmotic stress, and also that was for transcriptional of the gene through the is a of and the for of the element) was to be I. D. N. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). The element was found in the promoter region of the GLO1 gene, and the increased of the in the cells the glyoxalase I glyoxalase I was increased in the mutant by osmotic stress that expression of the GLO1 gene was the Expression of the CTT1 gene encoding cytosolic catalase has been known to be induced by conditions, such as heat shock, osmotic stress, oxidative stress, and on (2Schuller C. Brewster J.L. Alexander M.R. Gustin M.C. Ruis H. EMBO J. 1994; 13: 4382-4389Crossref PubMed Scopus (442) Google Scholar, 3Ruis H. Schuller C. BioEssays. 1995; 17: 959-965Crossref PubMed Scopus (359) Google Scholar). The CTT1 gene has in its promoter and such environmental signals have been thought to on the STRE (2Schuller C. Brewster J.L. Alexander M.R. Gustin M.C. Ruis H. EMBO J. 1994; 13: 4382-4389Crossref PubMed Scopus (442) Google Scholar). that CTT1 catalase was increased by heat shock, osmotic stress, oxidative stress, and On the expression of the GLO1 gene, which of was specifically induced by osmotic stress. induction was in the CTT1 or GLO1 gene. and Blomberg J. Blomberg A. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google several the expression of which was by in S. cerevisiae. a cis-element that to stress, as the the CTT1 the GLO1 gene has in the promoter Expression of the CTT1 gene under highly osmotic conditions was to be by STRE, and proteins Msn2p and Msn4p proved to be for transcriptional G. Schuller C. A. Ruis H. F. EMBO J. 1996; PubMed Scopus Google Scholar). As in catalase was in the hog1Δ mutant as as in the cells the wild type In the catalase was induced by osmotic the GLO1 gene expression was completely repressed in the as well as in the hog1Δ mutant. that some Msn2p and Msn4p be transcriptional of the CTT1 gene in osmotic stress response in S. such be in osmotic response of the GLO1 gene. expression of the GLO1 gene specifically to osmotic stress and is in the pathway, the GLO1 gene be a for of MAPK in S. cerevisiae. As in the consumption increased by osmotic stress in the wild type strain. and Blomberg J. Blomberg A. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google that expression of both of the gene, encoding and the gene, encoding was under highly osmotic conditions. S. cerevisiae glycerol as a compatible the cells are exposed to highly osmotic Glycerol is synthesized and the rate-limiting for glycerol production is a glycerol-3-phosphate dehydrogenase dehydrogenase is encoded by the GPD1 gene, and the gene expression under highly osmotic conditions is by Hog1p (14Albertyn J. Hohmann S. Thevelein J.M. Prior B.A. Mol. Cell. Biol. 1994; 14: 4135-4144Crossref PubMed Scopus (611) Google Scholar). The mutant in a a high of (14Albertyn J. Hohmann S. Thevelein J.M. Prior B.A. Mol. Cell. Biol. 1994; 14: 4135-4144Crossref PubMed Scopus (611) Google Scholar). Expression of the gene, encoding glycerol-3-phosphate was also to be by osmotic stress (16Norbeck J. Pahlman A.-K. Akhtar N. Blomberg A. Adler L. J. Biol. Chem. 1996; 271: 13875-13881Abstract Full Text Full Text PDF PubMed Scopus (190) Google Scholar). to high S. cerevisiae cells glycerol from glucose, and dihydroxyacetone phosphate is a On the methylglyoxal is also synthesized from and dihydroxyacetone phosphate is a substrate for methylglyoxal synthase (17Hopper D.J. Cooper R.A. Biochem. J. 1972; 128: 321-329Crossref PubMed Scopus (92) Google Scholar, 18Cooper R.A. Eur. J. Biochem. 1974; 44: 81-86Crossref PubMed Scopus Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar, S. M. J. Biol. Chem. Full Text PDF PubMed Google Scholar). Methylglyoxal is also from the PubMed Scopus Google Scholar, PubMed Scopus (190) Google Scholar). an increased of to the of intracellular methylglyoxal found that the of methylglyoxal in the mutant cells by increased approximately that in the cells. Glucose consumption was also increased approximately 30% by osmotic stress the for GLO1gene expression under highly osmotic conditions be to scavenge methylglyoxal that is increased in the adaptive response to high osmolarity also the that the CTT1 gene is also in osmotic stress conditions, in to in the dehydrogenase dihydroxyacetone phosphate from by the of and dihydroxyacetone phosphate is reduced to glycerol 3-phosphate. Glycerol 3-phosphate through the and to to and glycerol 3-phosphate is to dihydroxyacetone Dihydroxyacetone phosphate in is to the glycerol phosphate is to from in the therefore, increased of glycerol 3-phosphate from to the of of the in and it increase of the The gene and is to is one of the in found that the mutant on the A. S. and A. is also and it the therefore, expression of the CTT1 gene, which cytosolic is induced by osmotic stress to scavenge that from to F. W. S. and T. for and respectively. S. for of