Rab1b regulates vesicular transport between the endoplasmic reticulum and successive Golgi compartments.
We report an essential role for the ras-related small GTP-binding protein rab1b in vesicular transport in mammalian cells. mAbs detect rab1b in both the ER and Golgi compartments. Using an assay which reconstitutes transport between the ER and the cis-Golgi compartment, we find that rab1b is required during an initial step in export of protein from the ER. In addition, it is also required for transport of protein between successive cis- and medial-Golgi compartments. We suggest that rab1b may provide a common link between upstream and downstream components of the vesicular fission and fusion machinery functioning in early compartments of the secretory pathway.
Department of Molecular and Cellular Biology, Scripps Research Institute, La Jolla, California 92037.
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H
Plutner
A D
AD
Cox
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S
Pind
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Khosravi-Far
J R
JR
Bourne
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Schwaninger
C J
CJ
Der
W E
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Balch
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001692:Biological Transport; D015153:Blotting, Western; D002451:Cell Compartmentation; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D019204:GTP-Binding Proteins / Q000276:immunology / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D007425:Intracellular Membranes / Q000378:metabolism; D008099:Liver / Q000648:ultrastructure; D051381:Rats; D020761:rab1 GTP-Binding Proteins; D020693:rab2 GTP-Binding Protein
D000911:Antibodies, Monoclonal; D019204:GTP-Binding Proteins; C061569:RAB1B protein, rat; D020761:rab1 GTP-Binding Proteins; D020693:rab2 GTP-Binding Protein