• MeSH
• Cycloheximide pharmacology   MeSH
• Endocytosis physiology   MeSH
• Protein Synthesis Inhibitors pharmacology   MeSH
• Membrane Transport Proteins metabolism   MeSH
• Molecular Sequence Data MeSH
• Nucleotide Transport Proteins * MeSH
• Saccharomyces cerevisiae Proteins * MeSH
• Saccharomyces cerevisiae enzymology   MeSH
• Amino Acid Sequence MeSH
• Ubiquitins physiology   MeSH
• Vacuoles metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Cycloheximide MeSH
• FUR4 protein, S cerevisiae MeSH Browser
• Protein Synthesis Inhibitors MeSH
• Membrane Transport Proteins MeSH
• Nucleotide Transport Proteins * MeSH
• Saccharomyces cerevisiae Proteins * MeSH
• Ubiquitins 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

The strictly aerobic yeast Candida parapsilosis transports the nonmetabolizable monosaccharide 6-deoxy-D-glucose by an active process (inhibition by 2.4-dinitrophenol and other uncouplers but not by iodoacetamide), the accumulation ratio decreasing with increasing substrate concentration. Measured accumulation ratios are in agreement with those predicted from kinetic constants for influx and efflux. Energy for transport is probably required in the translocation step. The maximum rate is temperature-dependent with a transition point at 21 degrees C. the accumulation ratio is not. The uptake is most active at pH 4.5--8.5. It appears not to involve stoichiometric proton symport. The transport system is shared by D-glucose, D-mannose, D-galactose and possibly maltose but not by fructose, sucrose or pentoses. The apparent half-life of the transport system was 3.5--4 h.

• MeSH
• Aerobiosis MeSH
• Biological Transport, Active drug effects   MeSH
• Amino Acids metabolism   MeSH
• Candida metabolism   MeSH
• Deoxy Sugars metabolism   MeSH
• Deoxyglucose metabolism   MeSH
• Dicyclohexylcarbodiimide pharmacology   MeSH
• Dinitrophenols pharmacology   MeSH
• Uranyl Nitrate pharmacology   MeSH
• Iodoacetamide pharmacology   MeSH
• Carbonyl Cyanide m-Chlorophenyl Hydrazone pharmacology   MeSH
• Kinetics MeSH
• Hydrogen-Ion Concentration MeSH
• Carbohydrate Metabolism MeSH
• Temperature MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Amino Acids MeSH
• Deoxy Sugars MeSH
• Deoxyglucose MeSH
• Dicyclohexylcarbodiimide MeSH
• Dinitrophenols MeSH
• Uranyl Nitrate MeSH
• Iodoacetamide MeSH
• Carbonyl Cyanide m-Chlorophenyl Hydrazone MeSH

Inhibitors of energy metabolism (3-chlorophenylhydrazonomalononitrile, antimycin A, iodoacetamide, dicyclohexylcarbodiimide) but not of transport (uranyl ions) stimulate at low concentrations the uptake of L-leucine, L-glutamic acid, L-arginine and, to a lesser degree, of 2-aminoisobutyric acid in Saccharomyces cerevisiae. The effect is apparent only after augmenting the energy reserves of cells by preincubation with D-glucose or, more strikingly, with ethanol. It is absent in a mutant (op1) lacking the translocation system for ADP--ATP in mitochondria. The presence of two different energy reserves for amino acid transport is indicated (one in energy-poor, the other in energy-rich cells). The stimulating effect appears to be caused by a retarded degradation of the transport proteins as occurs at a lowered level of mitochondria-produced ATP.

• MeSH
• Adenosine Triphosphate metabolism   MeSH
• Biological Transport, Active drug effects   MeSH
• Amino Acids metabolism   MeSH
• Antimycin A pharmacology   MeSH
• Dicyclohexylcarbodiimide pharmacology   MeSH
• Iodoacetamide pharmacology   MeSH
• Carbonyl Cyanide m-Chlorophenyl Hydrazone pharmacology   MeSH
• Kinetics MeSH
• Leucine metabolism   MeSH
• Saccharomyces cerevisiae metabolism   MeSH
• Uranium pharmacology   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Adenosine Triphosphate MeSH
• Amino Acids MeSH
• Antimycin A MeSH
• Dicyclohexylcarbodiimide MeSH
• Iodoacetamide MeSH
• Carbonyl Cyanide m-Chlorophenyl Hydrazone MeSH
• Leucine MeSH
• Uranium MeSH