1887

Abstract

Mutants of the obligatory aerobic yeast were selected after treatment of wild-type cells with -methyl--nitro--nitrosoguanidine on glycerol/glutamic acid medium containing 1%2-deoxy--glucose. Rates of -glucose transport in the mutants were about one-tenth that of the wild-type, whereas the transport of -fructose and -xylose was unaffected. However, glucose transport in the mutants was inhibited by uncouplers (for example carbonyl cyanide -chlorophenylhydrazone) and, therefore, remained an energy-dependent process. One of the mutants, M8. was chosen for further characterization of the transport and metabolism of hexoses. Biochemical analysis of the hexose-ATP-kinase activities revealed the absence of glucokinase (EC 2.7.1.2) activity in M8. Thus, the phosphorylation capacity was reduced to one-tenth to one-fifteenth that of the wild-type, resulting in accumulation of -glucose which, in turn, slowed down net glucose uptake. With the help of the mutant, the stoicheiometry of the H/glucose symport in was determined to be one proton per molecule of -glucose transported.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-131-3-479
1985-03-01
2024-10-14
Loading full text...

Full text loading...

/deliver/fulltext/micro/131/3/mic-131-3-479.html?itemId=/content/journal/micro/10.1099/00221287-131-3-479&mimeType=html&fmt=ahah

References

  1. Alcorn M. E., Griffin C. C. 1978; A kinetic analysis of d-xylose transport in Rhodotorula glutinis . Biochimica et biophysica acta 510:361–371
    [Google Scholar]
  2. Bergmeyer H. U., Bernt E., Schmidt F., Stork H. 1974; d-glucose Bestimmung mit Hexokinase and Glucose-6-phosphat-Dehydrogenase. In Methoden der enzymatischen Analyse II1241–1246 Bergmeyer H. U. Weinheim: Verlag Chemie;
    [Google Scholar]
  3. Conway E. J., O’Maloney E. 1946; The nature of the cation exchanges during yeast fermentation with formation of 0·02 N H+ ion. Biochemical Journal 40:59–67
    [Google Scholar]
  4. Conway E. J., Ryan H., Carton E. 1954; Active transport of sodium ions from the yeast cell. Biochemical Journal 58:158–167
    [Google Scholar]
  5. Eddy A. A. 1978; Proton-dependent solute transport in microorganisms. Current Topics in Membranes and Transport 10:279–360
    [Google Scholar]
  6. Hauer R., Höfer M. 1978; Evidence for interactions between the energy-dependent transport of sugars and the membrane potential in the yeast Rhodotorula gracilis (Rhodosporidium toruloides). Journal of Membrane Biology 43:335–349
    [Google Scholar]
  7. Hauer R., Höfer M. 1982; Variable H+/substrate stoicheiometries in Rhodotorula gracilis are caused by a pH-dependent protonation of the carrier(s). Biochemical Journal 208:459–464
    [Google Scholar]
  8. Heller K. B., Höfer M. 1975; Temperature dependence of the energy-linked monosaccharide transport across the cell membrane of Rhodotorula gracilis . Journal of Membrane Biology 21:261–271
    [Google Scholar]
  9. Höfer M., Dahle P. 1972; Glucose repression of inducible enzyme synthesis in the yeast Rhodotorula gracilis : effect of the cell membrane transport. European Journal of Biochemistry 29:326–332
    [Google Scholar]
  10. Höfer M., Kotyk A. 1968; Tight coupling of monosaccharide transport and metabolism in Rhodotorula gracilis . Folia microbiologica 13:197–204
    [Google Scholar]
  11. Höfer M., Misra P. C. 1978; Evidence for a proton/sugar symport in the yeast Rhodotorula gracilus (glutinis). Biochemical Journal 172:15–22
    [Google Scholar]
  12. Höfer M., Betz A., Becker J.-U. 1970; Metabolism of the obligatory aerobic yeast Rhodotorula gracilis I. Changes in metabolite concentrations following d-glucose and d-xylose addition to the cell suspension. Archives of Microbiology 71:99–110
    [Google Scholar]
  13. Janda S., Kotyk A., Tauchova R. 1976; Monosaccharide transport systems in the yeast Rhodotorula glutinis . Archives of Microbiology 111:151–154
    [Google Scholar]
  14. Kotyk A., Höfer M. 1965; Uphill transport of sugars in the yeast Rhodotorula gracilis . Biochimica et biophysica acta 102:410–422
    [Google Scholar]
  15. Lang G., Michal G. 1974; d-glucose-6-phosphat und d-fructose-6-phosphat Bestimmung mit Glucose-6-phosphat-Dehydrogenase und Phosphoglu-cose-Isomerase. In Methoden der enzymatischen Analyse II1283–1287 Bergmeyer H. U. Weinheim: Verlag Chemie;
    [Google Scholar]
  16. Mahlberg D., Höfer M. 1984; Biochemical characterization of a glucose-negative mutant of the yeast Rhodotorula gracilis . Systematic and Applied Microbiology 5:269
    [Google Scholar]
  17. Niemietz C., Höfer M. 1984; Transport of an anionic substrate by the H+/monosaccharide symport in Rhodotorula gracilis: only the protonated form of the carrier is catalytically active. Journal of Membrane Biology 80:235–242
    [Google Scholar]
  18. Niemietz C., Hauer R., Höfer M. 1981; Active transport of charged substrates by a proton/sugar co-transport system. Biochemical Journal 194:433–441
    [Google Scholar]
  19. Rustum Y. M., Ramel A. H., Barnard E. A. 1971; The preparation of yeast hexokinases. Preparative Biochemistry 1:4309–329
    [Google Scholar]
/content/journal/micro/10.1099/00221287-131-3-479
Loading
/content/journal/micro/10.1099/00221287-131-3-479
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error