Trimeric G-proteins of the trans-Golgi network are involved in the formation of constitutive secretory vesicles and immature secretory granules

• Published in: FEBS letters 1991-12, Vol.294 (3), p.239-243
• Main Authors: Barr, Francis A., Leyte, Anja, Mollner, Stefan, Pfeuffer, Thomas, Tooze, Sharon A., Huttner, Wieland B.
• Format: Article
• Language: English
• Subjects: Adenosine Diphosphate Ribose - metabolism; ADP-ribosylation; Adrenal Gland Neoplasms; Aluminum - pharmacology; Aluminum Compounds; Biological and medical sciences; Cell physiology; Cell-Free System; Cell-free vesicle formation; Cytoplasmic Granules - physiology; Fluoride; Fluorides - pharmacology; Fundamental and applied biological sciences. Psychology; Golgi Apparatus - chemistry; Golgi Apparatus - ultrastructure; granules; GTP-Binding Proteins - antagonists & inhibitors; GTP-Binding Proteins - chemistry; GTP-Binding Proteins - physiology; guanine nucleotide-binding protein; Guanosine nucleotides; Macromolecular Substances; Molecular and cellular biology; Pertussis Toxin; Pheochromocytoma; Secretion. Exocytosis; Trimeric G-protein; Tumor Cells, Cultured; Virulence Factors, Bordetella - pharmacology; βγ Subunits
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(91)81438-E

Non-hydrolysable analogues of GTP, such as GTPγS and GMP-PNP, have previously been shown to inhibit the formation of constitutive secretory vesicles (CSVs) and immature secretory granules (ISGs) from the trans-Golgi network (TGN). Using a cell-free system, we show here that the formation of these vesicles is also inhibited by [AIF 4], a compound known to act on trimeric G-proteins. Addition of highly purified G-protein βγ subunits stimulated, in a differential manner, the cell-free formation of both CSVs and ISGs. ADP-ribosylation experiments revealed the presence of a pertussis toxin-sensitive G-protein α subunit in the TGN. We conclude that trimeric G-proteins regulate the formation of secretory vesicles from the TGN.