Sorting and budding of constitutive secretory vesicles in hepatocytes and hepatoma cells.
We have isolated a population of post-TGN secretory vesicles from hepatocytes. These vesicles of 100-150 nm diameter carry heparan sulfate proteoglycans. Secretory proteins (albumin, apo-lipoprotein E, fibrinogen) are sorted into different post-TGN secretory vesicles. A member of the ARF family of small GTP-binding proteins is associated with these vesicles. A unique peripheral membrane protein of these vesicles (VAPP14) was shown to exist also on the TGN. Brefeldin A leads to a dissociation of VAPP14 from the TGN. Antibodies against VAPP14 inhibit budding of proteoglycan containing vesicles from the TGN in a cell-free system. Inhibition occurred also in the presence of GTP-gamma-S. The same type of vesicles exists in H35 Reuber hepatoma cells.
Barthel
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A
Department of Clinical Biochemistry, Universität Göttingen, Germany.
Nickel
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W
Tonko
C
C
Söling
H D
HD
D000818:Animals; D020126:Brefeldin A; D002352:Carrier Proteins / Q000502:physiology; D002460:Cell Line; D003517:Cyclopentanes / Q000494:pharmacology; D003594:Cytoplasmic Granules / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006023:Glycoproteins; D006056:Golgi Apparatus / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate / Q000378:metabolism*; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism* / Q000502:physiology; D011509:Proteoglycans / Q000378:metabolism*; D051381:Rats; D050600:SNARE Proteins; D014407:Tumor Cells, Cultured; D033921:Vesicular Transport Proteins
D020126:Brefeldin A; D002352:Carrier Proteins; D003517:Cyclopentanes; D019204:GTP-Binding Proteins; D006023:Glycoproteins; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011509:Proteoglycans; D050600:SNARE Proteins; D033921:Vesicular Transport Proteins; C513045:Tgoln2 protein, rat; C090229:VAPP14 protein, rat