title: Coatomer and dimeric ADP ribosylation factor 1 promote distinct steps in membrane scission.
abstract: Formation of coated vesicles requires two striking manipulations of the lipid bilayer. First, membrane curvature is induced to drive bud formation. Second, a scission reaction at the bud neck releases the vesicle. Using a reconstituted system for COPI vesicle formation from purified components, we find that a dimerization-deficient Arf1 mutant, which does not display the ability to modulate membrane curvature in vitro or to drive formation of coated vesicles, is able to recruit coatomer to allow formation of COPI-coated buds but does not support scission. Chemical cross-linking of this Arf1 mutant restores vesicle release. These experiments show that initial curvature of the bud is defined primarily by coatomer, whereas the membrane curvature modulating activity of dimeric Arf1 is required for membrane scission.
authors: Heidelberg University Biochemistry Center, Heidelberg University, 69120 Heidelberg, Germany.
authors: Rainer
authors: R
authors: Beck
authors: Simone
authors: S
authors: Prinz
authors: Petra
authors: P
authors: Diestelkötter-Bachert
authors: Simone
authors: S
authors: Röhling
authors: Frank
authors: F
authors: Adolf
authors: Kathrin
authors: K
authors: Hoehner
authors: Sonja
authors: S
authors: Welsch
authors: Paolo
authors: P
authors: Ronchi
authors: Britta
authors: B
authors: Brügger
authors: John A G
authors: JA
authors: Briggs
authors: Felix
authors: F
authors: Wieland
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000235:genetics / Q000378:metabolism*; D019943:Amino Acid Substitution / Q000502:physiology; D000818:Animals; D001324:Autoantigens / Q000378:metabolism; D022181:COP-Coated Vesicles / Q000502:physiology* / Q000648:ultrastructure; D020756:Coatomer Protein / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000378:metabolism / Q000528:radiation effects; D020285:Cryoelectron Microscopy; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D003598:Cytoskeletal Proteins; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism; D006056:Golgi Apparatus / Q000473:pathology / Q000502:physiology; D006160:Guanosine Triphosphate / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007425:Intracellular Membranes / Q000502:physiology; D008051:Lipid Bilayers / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D009154:Mutation / Q000502:physiology; D009237:N-Acetyllactosamine Synthase / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D055668:Photochemical Processes; D011485:Protein Binding / Q000502:physiology; D055503:Protein Multimerization / Q000502:physiology; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014162:Transfection; D053835:Unilamellar Liposomes / Q000378:metabolism; D043323:alpha-Mannosidase / Q000378:metabolism
chemical_list: D001324:Autoantigens; D020756:Coatomer Protein; D003432:Cross-Linking Reagents; D003598:Cytoskeletal Proteins; D020690:GTPase-Activating Proteins; C097741:Golgin subfamily A member 2; D008051:Lipid Bilayers; D008565:Membrane Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; C109331:TRIP11 protein, human; D053835:Unilamellar Liposomes; C102474:cytohesin-2; D006160:Guanosine Triphosphate; D009237:N-Acetyllactosamine Synthase; D043323:alpha-Mannosidase; D020823:ADP-Ribosylation Factor 1; D003545:Cysteine