Cell Structure and Function
Online ISSN : 1347-3700
Print ISSN : 0386-7196
ISSN-L : 0386-7196
Folimycin (Concanamycin A), a Specific Inhibitor of V-ATPase, Blocks Intracellular Translocation of the Glycoprotein of Vesicular Stomatitis Virus before Arrival to the Golgi Apparatus
Makoto MuroiNobue ShiragamiKenji NagaoMakari YamasakiAkira Takatsuki
Author information

1993 Volume 18 Issue 3 Pages 139-149


Folimycin (concanamycin A) specifically inhibited vacuolar-type ATPase as far as examined. Folimycin blocked excretion of the glycoprotein (G protein) of vesicular stomatitis virus into the medium and, instead, G protein was accumulated intracellularly. The intracellularly accumulated G protein electrophoresed a little faster than mature one. The N-glycan of the G protein was endoglycosidase H-sensitive, and terminal galactose and N-acetylglucosamine were not detected essentially on sequential digestion with exoglycosidases, indicating that processings known to occur in the Golgi apparatus do not take place in the presence of folimycin. The oligosaccharide chain of the G protein was determined to have a composition of Man8GlcNAc2 as analyzed by Bio-Gel P-4 column chromatography and high-performance liquid chromatography following digestion with α- and then with β-mannosidase. Activities of mannosidase I and glycosyltransferases prepared from baby hamster kidney cells were not inhibited as far as examined, indicating that the incompleteness of the N-glycosidic chain in folimycin-treated cells is not caused by inhibition of processing enzymes. Taken together these observations suggest that folimycin blocks the intracellular translocation of G protein before the step of trimming by mannosidase I which is confined to the cis compartment of the Golgi. The intracellular localization of G protein as revealed by fluorescence microscopy was in good accordance with this assumption.

Information related to the author
© Japan Society for Cell Biology
Previous article Next article