Mapmodulin, cytoplasmic dynein, and microtubules enhance the transport of mannose 6-phosphate receptors from endosomes to the trans-golgi network.
Late endosomes and the Golgi complex maintain their cellular localizations by virtue of interactions with the microtubule-based cytoskeleton. We study the transport of mannose 6-phosphate receptors from late endosomes to the trans-Golgi network in vitro. We show here that this process is facilitated by microtubules and the microtubule-based motor cytoplasmic dynein; transport is inhibited by excess recombinant dynamitin or purified microtubule-associated proteins. Mapmodulin, a protein that interacts with the microtubule-associated proteins MAP2, MAP4, and tau, stimulates the microtubule- and dynein-dependent localization of Golgi complexes in semi-intact Chinese hamster ovary cells. The present study shows that mapmodulin also stimulates the initial rate with which mannose 6-phosphate receptors are transported from late endosomes to the trans-Golgi network in vitro. These findings represent the first indication that mapmodulin can stimulate a vesicle transport process, and they support a model in which the microtubule-based cytoskeleton enhances the efficiency of vesicle transport between membrane-bound compartments in mammalian cells.
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Department of Biochemistry, Stanford University School of Medicine, Stanford, California 94305-5307, USA.
Ulitzur
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Mühlbauer
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Pfeffer
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SR
D000818:Animals; D001692:Biological Transport; D016466:CHO Cells / Q000187:drug effects / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D002417:Cattle; D006224:Cricetinae; D003593:Cytoplasm / Q000378:metabolism; D000072159:Dynactin Complex; D004398:Dyneins / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism*; D015739:Nocodazole / Q000494:pharmacology; D009687:Nuclear Proteins; D017239:Paclitaxel / Q000494:pharmacology; D011506:Proteins / Q000378:metabolism*; D016601:RNA-Binding Proteins; D017527:Receptor, IGF Type 2 / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D033921:Vesicular Transport Proteins; D016875:tau Proteins / Q000235:genetics / Q000378:metabolism
C087425:ANP32A protein, human; D002352:Carrier Proteins; C000606361:DCTN2 protein, human; D000072159:Dynactin Complex; D047908:Intracellular Signaling Peptides and Proteins; C489788:MAP2 protein, human; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D011506:Proteins; D016601:RNA-Binding Proteins; D017527:Receptor, IGF Type 2; D011994:Recombinant Proteins; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D033921:Vesicular Transport Proteins; D016875:tau Proteins; D004398:Dyneins; D017239:Paclitaxel; D015739:Nocodazole