This study investigates the physiological role and mechanism of vacuolar proteolysis in *Saccharomyces cerevisiae* using mutant cells lacking proteinase A, B, and carboxypeptidase Y. The researchers observed that these mutant cells accumulated spherical bodies in their vacuoles under nutrient-deficient conditions, which were later named "autophagic bodies." These bodies contained cytoplasmic components such as ribosomes, rough endoplasmic reticulum (RER), mitochondria, lipid granules, and glycogen granules. The accumulation of autophagic bodies was induced by nitrogen and carbon starvation, as well as depletion of specific amino acids. Genetic analysis revealed that the accumulation of autophagic bodies was due to the lack of the *PRBi* gene product, proteinase B. The study also demonstrated that the accumulation of autophagic bodies could be induced in wild-type cells by adding PMSF, a serine protease inhibitor. Biochemical analysis showed that the autophagic bodies contained latent activity of the cytosolic enzyme glucose-6-phosphate dehydrogenase. The results suggest that autophagy plays a crucial role in protein turnover under adverse conditions in yeast.This study investigates the physiological role and mechanism of vacuolar proteolysis in *Saccharomyces cerevisiae* using mutant cells lacking proteinase A, B, and carboxypeptidase Y. The researchers observed that these mutant cells accumulated spherical bodies in their vacuoles under nutrient-deficient conditions, which were later named "autophagic bodies." These bodies contained cytoplasmic components such as ribosomes, rough endoplasmic reticulum (RER), mitochondria, lipid granules, and glycogen granules. The accumulation of autophagic bodies was induced by nitrogen and carbon starvation, as well as depletion of specific amino acids. Genetic analysis revealed that the accumulation of autophagic bodies was due to the lack of the *PRBi* gene product, proteinase B. The study also demonstrated that the accumulation of autophagic bodies could be induced in wild-type cells by adding PMSF, a serine protease inhibitor. Biochemical analysis showed that the autophagic bodies contained latent activity of the cytosolic enzyme glucose-6-phosphate dehydrogenase. The results suggest that autophagy plays a crucial role in protein turnover under adverse conditions in yeast.