Abstract
The role of rab33b, a Golgi-specific rab protein, was investigated. Microinjection of rab33b mutants stabilised in the GTP-specific state resulted in a marked inhibition of anterograde transport within the Golgi and in the recycling of glycosyltransferases from the Golgi to the ER, respectively. A GST-rab33b fusion protein stabilised in its GTP form was found to interact by Western blotting or mass spectroscopy with Golgi protein GM130 and rabaptin-5 and rabex-5, two rab effector molecules thought to function exclusively in the endocytic pathway. A similar binding was seen to rab1 but not to rab6, both Golgi rabs. In contrast, rab5 was as expected, shown to bind rabaptin-5 and rabex-5 as well as the endosomal effector protein EEA1 but not GM130. No binding of EEA1 was seen to any of the Golgi rabs.
Publication types
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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Animals
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Autoantigens
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Biological Transport, Active
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Blotting, Western
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Brain
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Cattle
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Cytosol / metabolism
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Endoplasmic Reticulum / metabolism*
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Golgi Apparatus / metabolism*
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Guanine Nucleotide Exchange Factors / metabolism*
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Guanosine Triphosphate / metabolism
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HeLa Cells
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Humans
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Intracellular Fluid / metabolism
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Liver
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Mass Spectrometry
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Membrane Glycoproteins*
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Membrane Proteins / metabolism*
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Mutation
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Precipitin Tests
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Protein Binding
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Protein Transport
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Rats
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Recombinant Fusion Proteins / metabolism
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Vesicular Transport Proteins*
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Viral Envelope Proteins / metabolism
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rab GTP-Binding Proteins / genetics
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rab GTP-Binding Proteins / metabolism*
Substances
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Autoantigens
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G protein, vesicular stomatitis virus
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Golgin subfamily A member 2
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Guanine Nucleotide Exchange Factors
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Membrane Glycoproteins
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Membrane Proteins
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RABEP1 protein, human
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RABGEF1 protein, human
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Rabep1 protein, mouse
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Recombinant Fusion Proteins
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Vesicular Transport Proteins
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Viral Envelope Proteins
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Guanosine Triphosphate
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RAB33B protein, human
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rab GTP-Binding Proteins