Abstract
Exocytic transport from the endoplasmic reticulum (ER) to the Golgi complex has been visualized in living cells using a chimera of the temperature-sensitive glycoprotein of vesicular stomatitis virus and green fluorescent protein (ts-G-GFP[ct]). Upon shifting to permissive temperature, ts-G-GFP(ct) concentrates into COPII-positive structures close to the ER, which then build up to form an intermediate compartment or transport complex, containing ERGIC-53 and the KDEL receptor, where COPII is replaced by COPI. These structures appear heterogenous and move in a microtubule-dependent manner toward the Golgi complex. Our results suggest a sequential mode of COPII and COPI action and indicate that the transport complexes are ER-to-Golgi transport intermediates from which COPI may be involved in recycling material to the ER.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Biological Transport / physiology
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Carrier Proteins / metabolism*
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Cell Compartmentation / physiology
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Cell Membrane / metabolism
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Chlorocebus aethiops
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Coatomer Protein
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Endoplasmic Reticulum / metabolism*
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Exocytosis / physiology
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Golgi Apparatus / metabolism*
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Green Fluorescent Proteins
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Luminescent Proteins
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Membrane Glycoproteins*
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Membrane Proteins / metabolism*
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Microtubules / metabolism
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Phosphoproteins / metabolism*
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Recombinant Fusion Proteins / metabolism
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Saccharomyces cerevisiae Proteins*
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Temperature
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Vero Cells
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Vesicular Transport Proteins
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Viral Envelope Proteins
Substances
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Carrier Proteins
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Coatomer Protein
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G protein, vesicular stomatitis virus
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Luminescent Proteins
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Membrane Glycoproteins
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Membrane Proteins
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Phosphoproteins
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Recombinant Fusion Proteins
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SEC31 protein, S cerevisiae
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Saccharomyces cerevisiae Proteins
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Vesicular Transport Proteins
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Viral Envelope Proteins
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Green Fluorescent Proteins