Effects of starvation and glucose preincubation on membrane potential, ATPase-mediated acidification and glutamic acid transport were studied in yeast species Saccharomyces cerevisiae, Schizosaccharomyces pombe, Dipodascus magnusii, Lodderomyces elongisporus and Rhodotorula gracilis. The membrane potential was highest after preincubation with glucose in all species but L. elongisporus and R. gracilis. In all cases the membranes were depolarized in the presence of 20 mmol/L KCl and hyperpolarized with 50 mumol/L diethylstilbestrol (DES). The extracellular acidification caused by addition of glucose was highest after preincubation with glucose in all cases except in R. gracilis where there was none. In all cases except in R. gracilis addition of KCl caused a marked increase in the acidification rate. Addition of DES with glucose caused a large decrease in rate in S. cerevisiae but had much less effect on the other species. Transport of glutamic acid was clearly increased after pretreatment with glucose in S. cerevisiae, S. pombe and D. magnusii (mainly due to enhanced synthesis of the carrier) but actually decreased in R. gracilis and L. elongisporus. Addition of DES had an inhibitory effect in all species but much more pronounced in S. cerevisiae and S. pombe than in others. In general, both the acidification and the transport of glutamate were enhanced after preincubation with glucose but much more so in the semianaerobic species, such as S. cerevisiae, than in the strict aerobes (R. gracilis) where the effect was occasionally negative. There was no relationship between the ATPase-mediated acidification and the membrane potential.

• MeSH
• Biological Transport, Active MeSH
• Diethylstilbestrol pharmacology   MeSH
• Species Specificity MeSH
• Glucose pharmacology   MeSH
• Glutamates pharmacokinetics   MeSH
• Kinetics MeSH
• Hydrogen-Ion Concentration MeSH
• Yeasts drug effects   metabolism   MeSH
• Glutamic Acid MeSH
• Membrane Potentials drug effects   MeSH
• Proton-Translocating ATPases metabolism   MeSH
• Rhodotorula drug effects   metabolism   MeSH
• Saccharomyces cerevisiae drug effects   metabolism   MeSH
• Saccharomycetales drug effects   metabolism   MeSH
• Schizosaccharomyces drug effects   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Names of Substances
• Diethylstilbestrol MeSH
• Glucose MeSH
• Glutamates MeSH
• Glutamic Acid MeSH
• Proton-Translocating ATPases MeSH

The transport of inorganic phosphate anions into yeast cells (after preincubation with glucose, fructose or another metabolizable sugar, and in the presence of glucose) shows two kinetic components with half-saturation constants of 40 mumol/L and 2.4 mmol/L. The uptake was strikingly stimulated by 2-deoxy-D-glucose (2-dGlc) at lower concentrations but inhibited above 100 mmol/L. A similar stimulation was caused by adenine (0.01-1 mmol/L) and a very small one by uracil and inorganic sulfate. It is suggested that either a phosphorylation reaction accompanies the transport (2-dGlc) or that some compounds stimulate the H(+)-ATPase more than inorganic phosphate itself and thus increase its rate of transport.

• MeSH
• Adenine pharmacology   MeSH
• Adenosine Triphosphate metabolism   MeSH
• Deoxyglucose pharmacology   MeSH
• Phosphates metabolism   MeSH
• Phosphorylation MeSH
• Ion Transport drug effects   MeSH
• Kinetics MeSH
• Proton-Translocating ATPases metabolism   MeSH
• Saccharomyces cerevisiae drug effects   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Adenine MeSH
• Adenosine Triphosphate MeSH
• Deoxyglucose MeSH
• Phosphates MeSH
• Proton-Translocating ATPases MeSH

Protoplasts of Saccharomyces cerevisiae prepared by snail-gut juice treatment were compared in their transport properties with intact cells. 1. Constitutive monosaccharide transport (D-xylose, 6-deoxy-D-glucose), as well as inducible transport of D-galactose, were unaltered. 2. Phosphorylation-associated transport of 2-deoxy-D-glucose was enhanced in protoplasts, possibly as a consequence of removal of the unstirred layer of the cell wall. 3. Proton-driven transports of trehalose, L-leucine, L-proline and monophosphate could not be activated by preincubation with D-glucose, apparently owing to lack of proton-solute coupling in transport. Utilization of glucose was not depressed but respiration was reduced by about 50% while acidification of the external medium after glucose addition was inhibited by more than 90%. This may be related to the inability of protoplast plasma membrane H-ATPase to be activated by glucose and hence to impaired proton-translocating capacity. Uranyl ions inhibited generally much less in protoplasts than in intact cells although their binding to protoplasts was greater (maximum 0.68 fmol per cell but 3.2 fmol per protoplast).

• MeSH
• Biological Transport MeSH
• Ethanol metabolism   MeSH
• Glucose metabolism   MeSH
• Monosaccharides metabolism   MeSH
• Monosaccharide Transport Proteins MeSH
• Proton-Translocating ATPases metabolism   MeSH
• Protoplasts metabolism   MeSH
• Saccharomyces cerevisiae metabolism   MeSH
• Carrier Proteins metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Ethanol MeSH
• Glucose MeSH
• Monosaccharides MeSH
• Monosaccharide Transport Proteins MeSH
• Proton-Translocating ATPases MeSH
• Carrier Proteins MeSH

Maltotriose is metabolized by baker's and brewer's yeast only oxidatively, with a respiratory quotient of 1.0, the QCO2Ar being, depending on the strain used, 0-11, as compared with QCO2air of 6-42 microL CO2 per h per mg dry substance. The transport appeared to proceed by facilitated diffusion (no effects of NaF, iodoacetamide and 3-chlorophenylhydrazonomalononitrile) with a KT of more than 50 mM and was inhibited by maltose greater than maltotriose greater than methyl-alpha-D-glucoside greater than maltotetraose greater than D-fructose greater than D-glucose. The transport was present constitutively in both Saccharomyces cerevisiae (baker's yeast) and in S. uvarum (brewer's yeast) and it was not significantly stimulated by preincubation with glucose or maltose. The pH optimum was 4.5-5.5, the temperature dependence yielded an activation energy of 26 kJ/mol.

• MeSH
• Biological Transport MeSH
• Oligosaccharides metabolism   MeSH
• Saccharomyces cerevisiae metabolism   MeSH
• Saccharomyces metabolism   MeSH
• Oxygen Consumption MeSH
• Trisaccharides metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• maltotriose MeSH Browser
• Oligosaccharides MeSH
• Trisaccharides MeSH

Preincubation of baker's yeast (wild strain, respiration-deficient mutant and a low-phosphorus culture) with glucose, trehalose, and other metabolic sugars increases the subsequent uptake of inorganic phosphate 3-5 times. The Kt is reduced by the preincubation from 3.5 to 1.6 mM. The process involves primarily the production of glycolytic energy sources (suppression by iodoacetamide, no effect of antimycin or dicyclohexylcarbodiimide, negligible effect of ethanol, or respiratory mutation). The low-phosphorus yeast takes up phosphate anions about 1-20 times faster than the high-phosphorus (normal) culture. The stimulation is also accompanied by some (apparently nonessential) protein synthesis and has a halftime of 35 min; its decay has a t0.5 of 12 min but affects only less than one-half of the stimulated capacity.

• MeSH
• Phosphates metabolism   MeSH
• Glucose pharmacology   MeSH
• Saccharomyces cerevisiae metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Phosphates MeSH
• Glucose MeSH

• MeSH
• Acetamides pharmacology   MeSH
• Actinomycetales metabolism   MeSH
• Biological Transport, Active MeSH
• Anaerobiosis MeSH
• Azides pharmacology   MeSH
• Benzoates metabolism   MeSH
• Cell Membrane metabolism   MeSH
• Chloramphenicol pharmacology   MeSH
• Dinitrophenols pharmacology   MeSH
• Cell Fractionation MeSH
• Glucose pharmacology   MeSH
• Iodine MeSH
• Vanillic Acid metabolism   MeSH
• Manometry MeSH
• Carbon Dioxide biosynthesis   MeSH
• Oxidation-Reduction MeSH
• Carbon Radioisotopes MeSH
• Oxygen Consumption MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Acetamides MeSH
• Azides MeSH
• Benzoates MeSH
• Chloramphenicol MeSH
• Dinitrophenols MeSH
• Glucose MeSH
• Iodine MeSH
• Vanillic Acid MeSH
• Carbon Dioxide MeSH
• Carbon Radioisotopes MeSH