Abstract
Non-hydrolysable analogues of GTP, such as GTP gamma S 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 [A1F4]-, a compound known to act on trimeric G-proteins. Addition of highly purified G-protein beta gamma 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 alpha subunit in the TGN. We conclude that trimeric G-proteins regulate the formation of secretory vesicles from the TGN.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenosine Diphosphate Ribose / metabolism
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Adrenal Gland Neoplasms
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Aluminum / pharmacology
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Aluminum Compounds*
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Cell-Free System
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Cytoplasmic Granules / physiology*
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Fluorides / pharmacology
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GTP-Binding Proteins / antagonists & inhibitors
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GTP-Binding Proteins / chemistry
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GTP-Binding Proteins / physiology*
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Golgi Apparatus / chemistry*
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Golgi Apparatus / ultrastructure
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Macromolecular Substances
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Pertussis Toxin
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Pheochromocytoma
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Tumor Cells, Cultured
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Virulence Factors, Bordetella / pharmacology
Substances
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Aluminum Compounds
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Macromolecular Substances
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Virulence Factors, Bordetella
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Adenosine Diphosphate Ribose
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Aluminum
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Pertussis Toxin
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GTP-Binding Proteins
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Fluorides
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aluminum fluoride