Differential secretion of alpha 1-acid glycoprotein occurs in the Golgi complex of isolated rat hepatocytes. Evidence of partial retention in the Golgi.
Using weakly basic amines, we investigated the step at which the secretion kinetics of concanavalin-A-retained and nonretained alpha 1-acid glycoprotein glycoforms diverge in isolated rat hepatocytes. Both chloroquine and primaquine, whose action on protein secretion is targeted to terminal domains of the Golgi apparatus, cancelled the kinetic difference without influencing carbohydrate chain sialylation. To test for a possible interaction of alpha 1-acid glycoprotein with Golgi membranes, we also permeabilized control and primaquine-treated hepatocytes, as well as purified Golgi preparations, with saponin. In each case, we found that alpha 1-acid glycoprotein was associated with Golgi membranes, the association being more marked in primaquine-treated cells than in control cells. Membrane-bound alpha 1-acid glycoprotein appeared to be preferentially retained on concanavalin A. Such retention could account for the divergent secretion kinetics of alpha 1-acid glycoprotein glycoforms.
Poüs
C
C
Laboratoire de Biochimie Générale, Unité de Formation et de Recherche des Sciences Pharmaceutiques et Biologiques, Châtenay-Malabry, France.
Guibourdenche
J
J
Drechou
A
A
Durand
G
G
D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D002738:Chloroquine / Q000494:pharmacology; D003208:Concanavalin A / Q000494:pharmacology; D006031:Glycosylation; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D008099:Liver / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009961:Orosomucoid / Q000378:metabolism*; D011233:Precipitin Tests; D011319:Primaquine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012503:Saponins / Q000494:pharmacology
D009961:Orosomucoid; D012503:Saponins; D003208:Concanavalin A; D002738:Chloroquine; D011319:Primaquine