Main description:

Three parameters participating in the specific control of proteolytic processes in intact yeast cells are discussed: (1) different substrate specificity of the yeast proteinases A and B, and carboxypeptidase Y when tested with yeast enzymes as substrate, (2) three types of macro- molecular inhibitors from yeast specifically inhibiting the three pro- teinases, (3) subcellular localization of the proteinases in the vacu- oles and of the inhibitors in the cytosol. Mechanisms of a selective proteolysis of single enzymes or a group of enzymes dependent on chan- ges in the physiological conditions are discussed. References Betz, H., Hinze, H., Holzer, H.: Isolation and properties of two inhibitors of proteinase B from yeast. J. Bioi. Chem. 249, 4515-4521 (1974) Cabib, E., Farkas, V.: The control of morphogenesis: An enzymatic mechanism for the initiation of septum formation in yeast. Proc. Nat. Acad. Sci. U.S. 68, 2052-2056 (1971) Cabib, E., Keller, F.A.: Chitin and yeast budding. J. Bioi. Chem. 246, 167-173 (1971) Cabib, E., Ulane, R.: Chitin synthetase activating factor from yeast, a protease. Biochem. Biophys. Res. Commun. 50, 186-191 (1973) Hasilik, A.:
Inactivation of Chitin Synthase in Saccharomyces cerevisiae. Arch. Microbiol. 101, 295-301 (1974) Hasilik, A., Holzer,~: PartiCipation of the tryptophan synthase inactivating system from yeast in the activation of chitin synthase. Biochem. Biophys. Res.

Contents:

Interconversion in the Control of Glycogen Metabolism.- Concerted Regulation of Glycogen Metabolism and Muscle Contraction.- The Regulation of Glycogen Metabolism by Multivalent Phosphorylation.- Localization and Turnover of Phosphorylase Kinase in Rabbit Skeletal Muscle.- Probes in Studying the Architecture of Interconvertible Enzymes.- Hybridphosphorylases.- Purification and Properties of E. coli Maltodextrin Phosphorylase.- Excited-State vs Ground-State Structure of the Pyridoxal 5';-Phosphate Site in Glycogen Phosphorylase b.- Structure and Function of Regulatory Sites.- The Use of an Alternative Substrate as a Model System for the Study of Phosphorylase Kinase.- Restriction of the Allosteric Properties of Phosphorylase b by Single Links of a Bifunctional Reagent.- Interconvertible Forms of a cAMP-Dependent Protein Kinase from Bovine Cardiac Muscle.- Glycogen Synthase and Its Interconversion.- Studies on Glycogen Synthase and Its Control by Hormones.- Conversion into I Form of Glycogen Synthetase from Frog Muscle and Scallop Muscle.- Regulation of Adipose Tissue Glycogen Synthetase Activation.- The Phosphatases - Specific or Not.- Rabbit-Liver Glycogen Synthase: Properties and Interconversion by Phosphorylation and Dephosphorylation.- Recent Investigations on the Control of Glycogen Metabolism in the Liver.- Pyruvate Dehydrogenase - Assembly, Function and Control.- Structure and Regulation of the Mammalian Pyruvate Dehydrogenase Complex.- Metabolic Interconversion of the Pyruvate Dehydrogenase Complex as Related to the Mitochondrial Energy State.- Regulation of Pyruvate Dehydrogenase by End Product Inhibition and by Phosphorylation.- Adenylylation, ADP-Ribosylation and Phosphorylation as Regulatory Signals.- Metabolic Regulation of Coupled Covalent Modification Cascade Systems.- ADP-Ribosylation of Elongation Factor 2 by Pseudomonas aeruginosa Exotoxin A and by Diphtheria Toxin.- Protein-ADP-Ribosylating System of Mitochondria.- RNA Polymerase Modifications after T-Phage Infections of E. coli.- Specific Proteolysis - A Regulatory Device?.- Characteristics and Functions of Proteinases and Proteinase Inhibitors in Yeast.- Specific Proteolytic Modification of Rabbit Liver Fructose Biphosphatase under Gluconeogenic Conditions.- Regulation of Protein Turnover and the Role of Lysosomes.- In situ vs. in vivo Studies.- Study of Enzyme Activity in Animal Cells in situ.- The Glycolytic Pathway in Yeast. Study under in situ Conditions.- Interconversion of Rat Liver Phosphofructokinase by Phosphorylation and Dephosphorylation.- Unusual Modulations of Enzyme Action.- Histidine Decarboxylase from Lactobacillus 30a: Nature of Conversion of Proenzyme to Active Enzyme.- Reductive Generation of Vicinial Dithiols by Photosynthetic Electron Transport System is Involved in Light-Regulation of Chloroplast Enzyme Activity.- The Accumulation of Faulty Enzyme Molecules in Aging Cells.