Degradation of proteins and lipids in autophagic vacuoles and secretory vesicles.
Vinblastine induces increased occurrence of autophagosomes and inhibits export of secretory proteins in rat liver. Taking advantage of this induction and using a Metrizamide gradient it is possible to isolate a purified fraction consisting of intact autophagic vacuoles. These show high proteolytic activity and are enriched in lysosomal enzymes. In addition to autophagic vacuoles, isolated secretory vesicles actively degrade their contents when secretion is inhibited by vinblastine. Histochemical demonstration of acid phosphatase shows an increase in reaction products in the secretory vesicles from vinblastine treated rats. It is concluded that autophagic vacuoles can be isolated into high purity and that accumulation of secretory proteins and lipoproteins correlates with an increase in proteolysis and lipolysis in secretory vesicles.
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D001343:Autophagy; D002458:Cell Fractionation; D003594:Cytoplasmic Granules / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D050356:Lipid Metabolism; D008074:Lipoproteins / Q000378:metabolism; D008297:Male; D009940:Organoids / Q000378:metabolism*; D010587:Phagocytosis; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D014617:Vacuoles / Q000378:metabolism*; D014747:Vinblastine / Q000494:pharmacology
D008074:Lipoproteins; D011506:Proteins; D014747:Vinblastine; D000135:Acid Phosphatase