title: Bidirectional transport by distinct populations of COPI-coated vesicles.
abstract: Electron microscope immunocytochemistry reveals that both anterograde-directed (proinsulin and VSV G protein) and retrograde-directed (the KDEL receptor) cargo are present in COPI-coated vesicles budding from every level of the Golgi stack in whole cells; however, they comprise two distinct populations that together can account for at least 80% of the vesicles budding from Golgi cisternae. Segregation of anterograde- from retrograde-directed cargo into distinct sets of COPI-coated vesicles is faithfully reproduced in the cell-free Golgi transport system, in which VSV G protein and KDEL receptor are packaged into separable vesicles, even when budding is driven by highly purified coatomer and a recombinant ARF protein.
authors.affiliation: Department of Morphology, Faculty of Medicine, University of Geneva Medical Center, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Orci
authors.forename: M
authors.initials: M
authors.lastname: Stamnes
authors.forename: M
authors.initials: M
authors.lastname: Ravazzola
authors.forename: M
authors.initials: M
authors.lastname: Amherdt
authors.forename: A
authors.initials: A
authors.lastname: Perrelet
authors.forename: T H
authors.initials: TH
authors.lastname: Söllner
authors.forename: J E
authors.initials: JE
authors.lastname: Rothman
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001692:Biological Transport / Q000502:physiology; D002474:Cell-Free System; D002478:Cells, Cultured; D018699:Coated Vesicles / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D020756:Coatomer Protein; D006056:Golgi Apparatus / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism*; D016253:Microscopy, Immunoelectron; D010179:Pancreas / Q000166:cytology; D051381:Rats; D018000:Receptors, Peptide / Q000032:analysis
chemical_list: D020756:Coatomer Protein; C064459:KDEL receptor; D008565:Membrane Proteins; D018000:Receptors, Peptide