Initiation of selective proteolysis by metabolic interconversion.
After the addition of glucose to acetate- or ethanol-grown yeast cells a small group of selected enzymes is rapidly inactivated. This phenomenon has been called "catabolite inactivation". Among other enzymes participating in gluconeogenesis, fructose-1,6-bisphosphatase is inactivated during this catabolite inactivation process. It was shown by FUNAYAMA et al. (Eur. J. Biochem. 109, 61-66 (1980)) that the mechanism of inactivation is proteolysis. In the present paper evidence is presented that after addition of glucose a covalent conversion of the enzyme protein by phosphorylation of a serine-residue initiates its subsequent proteolysis. It is suggested that the covalent modification triggered by glucose and/or products of its catabolism renders the enzyme susceptible to proteinases and thereby initiates proteolysis of a selected enzyme without the necessity of a specific proteinase present.
D010450:Endopeptidases / Q000378:metabolism; D000939:Epitopes / Q000276:immunology; D006597:Fructose-Bisphosphatase / Q000037:antagonists & inhibitors* / Q000276:immunology / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology*; D007700:Kinetics; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D000939:Epitopes; D006597:Fructose-Bisphosphatase; D010450:Endopeptidases; D005947:Glucose