title: VIP36 localisation to the early secretory pathway.
abstract: VIP36, an integral membrane protein previously isolated from epithelial MDCK cells, is an intracellular lectin of the secretory pathway. Overexpressed VIP36 had been localised to the Golgi complex, plasma membrane and endocytic structures suggesting post-Golgi trafficking of this molecule (Fiedler et al., 1994). Here we provide evidence that endogenous VIP36 is localised to the Golgi apparatus and the early secretory pathway of MDCK and Vero cells and propose that retention is easily saturated. High resolution confocal microscopy shows partial overlap of VIP36 with Golgi marker proteins. Punctate cytoplasmic structures colocalise with coatomer and ERGIC-53, labeling ER-Golgi intermediate membrane structures. Cycling of VIP36 is suggested by colocalisation with anterograde cargo trapped in pre-Golgi structures and modification of its N-linked carbohydrate by glycosylation enzymes of medial Golgi cisternae. Furthermore, after brefeldin A treatment VIP36 is segregated from resident Golgi proteins and codistributes with ER-Golgi recycling proteins.
authors.affiliation: Cell Biology, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, D-69117 Heidelberg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Füllekrug
authors.forename: P
authors.initials: P
authors.lastname: Scheiffele
authors.forename: K
authors.initials: K
authors.lastname: Simons
mesh_terms: D017485:1-Deoxynojirimycin / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport; D015415:Biomarkers; D020126:Brefeldin A / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D002522:Chlorocebus aethiops; D020756:Coatomer Protein / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D004285:Dogs; D018871:Endoplasmic Reticulum, Smooth / Q000378:metabolism*; D006017:Glycolipids / Q000378:metabolism; D006023:Glycoproteins; D006031:Glycosylation / Q000187:drug effects; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D006825:Hybridomas / Q000166:cytology; D007668:Kidney / Q000166:cytology; D037241:Mannose-Binding Lectins; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012995:Solubility; D014162:Transfection; D014709:Vero Cells / Q000378:metabolism; D014721:Vesicular stomatitis Indiana virus / Q000502:physiology; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D015415:Biomarkers; D002352:Carrier Proteins; D020756:Coatomer Protein; D003902:Detergents; C028391:G protein, vesicular stomatitis virus; D006017:Glycolipids; D006023:Glycoproteins; C084004:LMAN1 protein, human; C086797:LMAN2 protein, human; D037241:Mannose-Binding Lectins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D011993:Recombinant Fusion Proteins; C072237:TGOLN2 protein, human; C490134:VIP36 protein, Canis familiaris; D014759:Viral Envelope Proteins; D017485:1-Deoxynojirimycin; D020126:Brefeldin A; D017351:N-Acetylglucosaminyltransferases; C024850:alpha-1,3-mannosyl-glycoprotein beta-1,2-N-acetylglucosaminyltransferase I