Abstract
Membrane trafficking from the endoplasmic reticulum (ER) to the Golgi complex is mediated by pleiomorphic carrier vesicles that are driven along microtubule tracks by the action of motor proteins. Here we describe how NSP4, a rotavirus membrane glycoprotein, binds to microtubules and blocks ER-to-Golgi trafficking in vivo. NSP4 accumulates in a post-ER, microtubule-associated membrane compartment and prevents targeting of vesicular stomatitis virus glycoprotein (VSV-G) at a pre-Golgi step. NSP4 also redistributes beta-COP and ERGIC53, markers of a vesicular compartment that dynamically cycles between the ER and Golgi, to structures aligned along linear tracks radiating throughout the cytoplasm. This block in membrane trafficking is released when microtubules are depolymerized with nocodazole, indicating that vesicles containing NSP4 are tethered to the microtubule cytoskeleton. Disruption of microtubule-mediated membrane transport by a viral glycoprotein may represent a novel pathogenic mechanism and provides a new experimental tool for the dissection of early steps in exocytic transport.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Antineoplastic Agents / pharmacology
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Antineoplastic Agents, Phytogenic / pharmacology
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COS Cells
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Cell Line
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Cell Membrane / metabolism
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Coatomer Protein / metabolism
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Cytoplasm / metabolism
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Cytoskeleton / metabolism
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DNA-Directed RNA Polymerases*
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Dose-Response Relationship, Drug
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Electrophoresis, Polyacrylamide Gel
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Endoplasmic Reticulum / metabolism
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Exocytosis
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Fluorescent Antibody Technique
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Glutathione Transferase / metabolism
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Glycoproteins / metabolism*
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Glycoside Hydrolases / pharmacology
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Golgi Apparatus / metabolism
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Macaca mulatta
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Mannose-Binding Lectins*
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Membrane Glycoproteins*
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Membrane Proteins / metabolism
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Microscopy, Confocal
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Microtubules / metabolism*
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Models, Biological
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Nocodazole / pharmacology
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Paclitaxel / pharmacology
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Plasmids / metabolism
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Precipitin Tests
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Protein Structure, Tertiary
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Protein Transport
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Recombinant Fusion Proteins / metabolism
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Rotavirus / metabolism*
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Time Factors
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Transfection
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Tubulin / metabolism
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Viral Envelope Proteins / metabolism
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Viral Nonstructural Proteins / metabolism*
Substances
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Antineoplastic Agents
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Antineoplastic Agents, Phytogenic
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Coatomer Protein
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G protein, vesicular stomatitis virus
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Glycoproteins
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Mannose-Binding Lectins
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Membrane Glycoproteins
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Membrane Proteins
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Recombinant Fusion Proteins
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Tubulin
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Viral Envelope Proteins
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Viral Nonstructural Proteins
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Glutathione Transferase
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DNA-Directed RNA Polymerases
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Glycoside Hydrolases
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Paclitaxel
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Nocodazole