1887

Abstract

In mutants of , which are defective in glucose repression of several enzymes, growth is inhibited if maltose is present in the medium. After adding [C]maltose to cultures growing with ethanol, maltose metabolism was followed in both mutant and wild-type cells. The amount of radioactivity incorporated was much higher in than in wild-type cells. Most of the radioactivity in cells was located in the low molecular mass fraction. Pulse-chase experiments showed that 2 h after addition of maltose, cells hydrolysed maltose to glucose, which was partially excreted into the medium. P-NMR studies gave evidence that turnover of sugar phosphates was completely abolished in cells after 2 h incubation with maltose. C-NMR spectra confirmed these results: unlike those for the wild-type, no resonances corresponding to fermentation products (ethanol, glycerol) were found for cells, whereas there were resonances corresponding to glucose. Although maltose is taken up by proton symport, the internal pH in the mutant did not change markedly during the 5 h after adding maltose. The intracellular accumulation of glucose seems to explain the inhibition of growth by maltose, probably by means of osmotic damage and/or unspecific -glycosylation of proteins. Neither maltose permease nor maltase was over-expressed, and so these enzymes were not the cause of glucose accumulation. Hence, the coordination of maltose uptake, hydrolysis to glucose and glycolysis of glucose is not regulated simply by the specific activity of the catabolic enzymes involved. The results indicate that there is an unknown regulatory mechanism, under control of , which coordinates glycolytic flux and maltose uptake. Furthermore, the excretion of accumulated glucose into the medium gives clear evidence that at least one glucose carrier in acts passively and transports glucose in both directions.

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1990-05-01
2021-05-09
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References

  1. Carlson M. 1987; Regulation of sugar utilization in Saccharomyces cerevisiae species. Journal of Bacteriology 169:4873–4877
    [Google Scholar]
  2. Cerami A., Vlassara H., Brownlee M. 1987; Glucose und altern. Spektrum der Wissenschaft 7:44–51
    [Google Scholar]
  3. Entian K.-D. 1980a; Genetic and biochemical evidence for hexokinase PII as a key enzyme involved in carbon catabolite repression in yeast. Molecular and General Genetics 178:633–637
    [Google Scholar]
  4. Entian K.-D. 1980b; A defect in carbon catabolite repression associated with uncontrollable and excessive maltose uptake. Molecular and General Genetics 179:169–175
    [Google Scholar]
  5. Entian K.-D. 1981; A carbon catabolite repression mutant of Saccharomyces cerevisiae with elevated hexokinase activity: evidence for a regulatory control of hexokinase PII synthesis. Molecular and General Genetics 184:278–282
    [Google Scholar]
  6. Entian K.-D. 1986; Glucose repression: a complex regulatory system in yeast. Microbiological Sciences 3:366–371
    [Google Scholar]
  7. Entian K.-D., Mecke D. 1982; Genetic evidence for a role of hexokinase isoenzyme PII in carbon catabolite repression in Saccharomyces cerevisiae. . Journal of Biological Chemistry 257:870–874
    [Google Scholar]
  8. Entian K.-D., Zimmermann F.K. 1980; Glycolytic enzymes and intermediates in carbon catabolite repression mutants of Saccharomyces cerevisiae. . Molecular and General Genetics 177:345–350
    [Google Scholar]
  9. Entian K.-D., Hilberg F., Opitz H., Mecke D. 1985; Cloning of hexokinase structural genes from Saccharomyces cerevisiae mutants with regulatory mutations responsible for glucose repression. Molecular and Cellular Biology 5:3035–3040
    [Google Scholar]
  10. Entian K.-D., Rose M., Albig W., Schuller H.-J., Niederacher D., Graack H.-R., Hassler S., Dussling G. 1987; Analysis of genes involved in glucose repression and derepression in Saccharomyces cerevisiae. . Foundation for Biotechnical and Industrial Fermentation Research 5:75–89
    [Google Scholar]
  11. Gage R.A., Van Wijngaarden W., Theuvenet A.P.R., Borst-Pauwels G.W.F.H., Haasnoot C.A.G. 1984; Localization and identification of the compound causing peak ‘X’ in the 31P- NMR spectrum of Saccharomyces cerevisiae. . Biochimica et Biophysica Acta 804:341–347
    [Google Scholar]
  12. Gancedo J.M., Gancedo C. 1986; Catabolite repression of yeast. FEMS Microbiology Reviews 32:179–187
    [Google Scholar]
  13. Gillies R.J., Alger J.R., Den Hollander J.A., Shulman R.G. 1982; Intracellular pH measured by NMR: methods and results. In: Intracellular pH: Its Measurement, Regulation and Utilization in Cellular Functions pp 79–104 New York: Alan R. Liss.;
    [Google Scholar]
  14. Loureiro-Dias M.C., Peinado J.M. 1984; Transport of maltose in Saccharomyces cerevisiae. Effect of pH and potassium ions. Biochemical Journal 222:293–298
    [Google Scholar]
  15. Navon G., Shulman R.G., Yamane T., Eccleshal T.R., Lam K.-B., Baronofsky J.J., Marmur J. 1979; Phosphorus-31 nuclear magnetic resonance studies of wild-type and glycolytic pathway mutants of Saccharomyces cerevisiae. . Biochemistry 18:4487–4489
    [Google Scholar]
  16. Niederacher D., Entian K.-D. 1985; Isolation and characterization of the regulatory HEX2 gene necessary for glucose repression in yeast. Molecular and General Genetics 206:505–509
    [Google Scholar]
  17. Rottenberg H. 1979; The measurement of membrane potential and △pH in cells, organelles and vesicles. Methods in Enzymology 55:547–569
    [Google Scholar]
  18. Santos H., Turner D.L. 1986; Characterization of the improved sensitivity obtained using a flow method for oxygenating and mixing cell suspensions in NMR. Journal of Magnetic Resonance 68:345–349
    [Google Scholar]
  19. Serrano R. 1977; Energy requirements for maltose transport in yeast. European Journal of Biochemistry 80:97–102
    [Google Scholar]
  20. Zamenhoff S. 1957; Preparation and assay of deoxyribonucleic acid from animal tissue. Methods in Enzymology 3:696–704
    [Google Scholar]
  21. Zimmermann F.K., Khan N.A., Eaton N.R. 1973; Identification of new genes involved in disaccharide fermentation in yeast. Molecular and General Genetics 123:29–41
    [Google Scholar]
  22. Zimmermann F.K., Scheel I. 1977; Mutants of Saccharomyces cerevisiae resistant to carbon catabolite repression. Molecular and General Genetics 154:75–82
    [Google Scholar]
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