Turnover of Yeast Fructose-Bisphosphatase in Different Metabolic Conditions

Abstract

Earlier work demonstrated that addition of glucose to yeast growing on noncarbohydrate carbon sources sharply reduces the levels of fructose bisphosphatase. This report indicates that the decrease in the levels of fructose bisphosphatase is accompanied by a parallel decrease of cross‐reacting material to specific antibody to fructose bisphosphatase. Use of the specific antibody shows that the loss of activity is irreversible and that its reappearance requires synthesis of protein de novo. The protein is highly stable during growth in ethanol (half life about 90 h). Addition of glucose increases the rate of degradation about 200‐fold. It is shown that the values of the rates of synthesis and degradation of fructose bisphosphatase vary with the metabolic situation of the yeast.

Irreversible inactivation of Saccharomyces cerevisiae fructose‐1,6‐bisphosphatase independent of protein phosphorylation at Ser11

“…Inactivation is the result of irreversible proteolytic degradation, since the amount of immune-precipitable protein corresponded exactly with the decrease in enzyme activity. This was first demonstrated for cytoplasmic malate dehydrogenase (EC 1.1.1.37) [8] and also confirmed for FBPase [9] and PEP carboxykinase [10]. However, Lenz and Holzer [11], using glucose-grown cells in stationary phase, observed that FBPase inactivation remained reversible during the first few minutes of inactivation.…”

Allantoinase from Pseudomonas aeruginosa Purification, properties and immunochemical characterization of its in vivo inactivation

“…The catabolite inactivation of gluconeogenic enzymes of Saccharomyces cerevisiae was shown to be accompanied by a loss of material immunochemically related to the enzymes [6,15,16], and the same was found for the inactivation of the NAD-and NADP-dependent glutamate dehydrogenases [5,17]. Definite proof for proteolysis would be obtained by the elucidation of the mechanism and by the isolation of protease mutants with altered inactivation.…”

Toxicity of 3‐O‐methyl glucose in yeast is due to its phosphorylation by glucokinase

“…Growth was followed turbidimetrically at 660 nm. Extracts for determination of enzymatic activity were obtained as in [6]. Glucokinase, hexokinase PI and PI1 were partially purified as described [7].…”