Discrimination between constitutive secretion and basal secretion from the regulated secretory pathway in GH3 cells.
The present experiments were undertaken to characterize basal release from vesicles of the regulated secretory pathway. In transfected GH3 cells, progastrin was released by the constitutive route, and mature, bioactive, amidated gastrin by the regulated secretory pathway. Studies using brefeldin A and bafilomycin A1 which inhibit progression through the Golgi complex suggested that both basal and stimulated release of amidated gastrin originated from mature secretory granules. Basal, but not stimulated, secretion of amidated gastrin was strongly inhibited at 22 degrees C. Mature secretory vesicles therefore support both basal and evoked secretion although the mechanisms underlying the two processes differ in their temperature sensitivity.
Varro
A
A
Physiological Laboratory, University of Liverpool, UK.
Nemeth
J
J
Dickinson
C J
CJ
Yamada
T
T
Dockray
G J
GJ
D000577:Amides; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D020126:Brefeldin A; D002478:Cells, Cultured; D003517:Cyclopentanes / Q000494:pharmacology; D003594:Cytoplasmic Granules / Q000378:metabolism; D018870:Endoplasmic Reticulum, Rough / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005755:Gastrins / Q000737:chemistry / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D018942:Macrolides; D010902:Pituitary Gland / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D011498:Protein Precursors / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors; D051381:Rats; D011994:Recombinant Proteins; D012636:Secretory Rate / Q000187:drug effects; D013696:Temperature; D014162:Transfection; D014407:Tumor Cells, Cultured; D025262:Vacuolar Proton-Translocating ATPases
D000577:Amides; D000900:Anti-Bacterial Agents; D003517:Cyclopentanes; D004791:Enzyme Inhibitors; D005755:Gastrins; D018942:Macrolides; D011498:Protein Precursors; D011994:Recombinant Proteins; D020126:Brefeldin A; C013706:big gastrin; D011189:Potassium Chloride; C040929:bafilomycin A1; D025262:Vacuolar Proton-Translocating ATPases; D006180:Proton-Translocating ATPases