The overexpression of GMAP-210 blocks anterograde and retrograde transport between the ER and the Golgi apparatus.
Golgi Microtubule-Associated Protein (GMAP)-210 is a peripheral coiled-coil protein associated with the cis-Golgi network that interacts with microtubule minus ends. GMAP-210 overexpression has previously been shown to perturb the microtubule network and to induce a dramatic enlargement and fragmentation of the Golgi apparatus (Infante C, Ramos-Morales F, Fedriani C, Bornens M, Rios RM. J Cell Biol 1999; 145: 83-98). We now report that overexpressing GMAP-210 blocks the anterograde transport of both a soluble form of alkaline phosphatase and the hemagglutinin protein of influenza virus, an integral membrane protein, between the endoplasmic reticulum and the cis/medial (mannosidase II-positive) Golgi compartment. Retrograde transport of the Shiga toxin B-subunit is also blocked between the Golgi apparatus and the endoplasmic reticulum. As a consequence, the B-subunit accumulates in compartments positive for GMAP-210. Ultrastructural analysis revealed that, under these conditions, the Golgi complex is totally disassembled and Golgi proteins as well as proteins of the intermediate compartment are found in vesicle clusters distributed throughout the cell. The role of GMAP-210 on membrane processes at the interface between the endoplasmic reticulum and the Golgi apparatus is discussed in the light of the property of this protein to bind CGN membranes and microtubules.
Pernet-Gallay
Karin
K
CNRS UMR 144, Institut Curie Section de Recherche, 26, rue d'Ulm, 75248 Paris Cedex 05, France.
Antony
Claude
C
Johannes
Ludger
L
Bornens
Michel
M
Goud
Bruno
B
Rios
Rosa M
RM
D000469:Alkaline Phosphatase / Q000378:metabolism; D022162:Cytoplasmic Vesicles / Q000378:metabolism / Q000648:ultrastructure; D003598:Cytoskeletal Proteins; D004351:Drug Resistance; D010450:Endopeptidases / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D006367:HeLa Cells; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009687:Nuclear Proteins; D021122:Protein Subunits / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D022621:Shiga Toxin / Q000737:chemistry / Q000378:metabolism; D014407:Tumor Cells, Cultured
D003598:Cytoskeletal Proteins; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D021122:Protein Subunits; C109331:TRIP11 protein, human; D022621:Shiga Toxin; D000469:Alkaline Phosphatase; D010450:Endopeptidases