Abstract
GTP gamma S irreversibly inhibits protein transport between successive compartments of the Golgi stack in a cell-free system. Fluoride, potentiated by the addition of aluminum ion, also causes a strong inhibition. These are hallmarks of the involvement of a guanine nucleotide-binding or regulatory "G" protein. Inhibition by GTP gamma S requires a cytosolic inhibitory factor that binds to Golgi membranes during inhibition. Preincubation experiments reveal that GTP gamma S blocks the function of acceptor Golgi but not donor Golgi membranes. More specifically, a processing step in between vesicle attachment and the actual fusion event seems to be affected. Electron microscopy demonstrates a corresponding 5-fold accumulation of non-clathrin-coated buds and vesicles associated with the Golgi cisternae during inhibition by GTP gamma S.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Aluminum / pharmacology
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Aluminum Compounds*
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Animals
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Biological Transport / drug effects
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Cell Line
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Cell-Free System
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Fluorides / pharmacology
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GTP-Binding Proteins / metabolism*
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Golgi Apparatus / metabolism*
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Golgi Apparatus / ultrastructure
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Guanosine 5'-O-(3-Thiotriphosphate)
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Guanosine Triphosphate / analogs & derivatives
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Guanosine Triphosphate / pharmacology
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Intracellular Membranes / metabolism
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Membrane Glycoproteins*
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Microscopy, Electron
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Thionucleotides / pharmacology
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Vesicular stomatitis Indiana virus
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Viral Envelope Proteins*
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Viral Matrix Proteins / metabolism*
Substances
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Aluminum Compounds
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G protein, vesicular stomatitis virus
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Membrane Glycoproteins
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Thionucleotides
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Viral Envelope Proteins
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Viral Matrix Proteins
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Guanosine 5'-O-(3-Thiotriphosphate)
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Guanosine Triphosphate
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Aluminum
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GTP-Binding Proteins
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Fluorides
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aluminum fluoride