Effects of brefeldin A on autophagy in cultured rat fibroblasts.
Effects of brefeldin A on cellular autophagy were studied in cultured rat fibroblasts. Brefeldin A inhibits the activation and membrane-binding properties of most ADP-ribosylation factors and causes the redistribution of Golgi proteins into the endoplasmic reticulum. Immunofluorescence and enzyme cytochemical methods revealed the disappearance of the Golgi apparatus and trans-Golgi network during the brefeldin A incubation. The volume fractions of autophagic vacuoles increased about threefold in cells treated with brefeldin A for 4 h and about sixfold in serum-deprived cells as compared with controls. When cells were first treated with brefeldin A for 1 h and were then deprived of serum and treated with brefeldin A for 3 h, the volume fraction of autophagic vacuoles increased about 4.5-fold as compared with untreated cells. The results showed that brefeldin A is unable to prevent serum deprivation-induced accumulation of autophagic vacuoles and that brefeldin A even when acting alone increases the volume fraction of autophagic vacuoles. It was concluded that an intact Golgi apparatus and trans-Golgi network are not essential for the formation of autophagic vacuoles. It seems also probable that ADP-ribosylation factors are not needed when vacuoles are formed.
Purhonen
P
P
Department of Cell Biology, University of Jyväskylä, Finland.
Pursiainen
K
K
Reunanen
H
H
D000135:Acid Phosphatase / Q000032:analysis; D000818:Animals; D001343:Autophagy / Q000187:drug effects*; D020126:Brefeldin A; D002478:Cells, Cultured; D003517:Cyclopentanes / Q000494:pharmacology*; D005347:Fibroblasts / Q000166:cytology*; D006056:Golgi Apparatus / Q000187:drug effects; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D051381:Rats; D013834:Thiamine Pyrophosphatase / Q000032:analysis; D014617:Vacuoles / Q000187:drug effects*
D003517:Cyclopentanes; D011500:Protein Synthesis Inhibitors; D020126:Brefeldin A; D000135:Acid Phosphatase; D013834:Thiamine Pyrophosphatase