title: Membrane fission is promoted by insertion of amphipathic helices and is restricted by crescent BAR domains.
abstract: Shallow hydrophobic insertions and crescent-shaped BAR scaffolds promote membrane curvature. Here, we investigate membrane fission by shallow hydrophobic insertions quantitatively and mechanistically. We provide evidence that membrane insertion of the ENTH domain of epsin leads to liposome vesiculation, and that epsin is required for clathrin-coated vesicle budding in cells. We also show that BAR-domain scaffolds from endophilin, amphiphysin, GRAF, and β2-centaurin limit membrane fission driven by hydrophobic insertions. A quantitative assay for vesiculation reveals an antagonistic relationship between amphipathic helices and scaffolds of N-BAR domains in fission. The extent of vesiculation by these proteins and vesicle size depend on the number and length of amphipathic helices per BAR domain, in accord with theoretical considerations. This fission mechanism gives a new framework for understanding membrane scission in the absence of mechanoenzymes such as dynamin and suggests how Arf and Sar proteins work in vesicle scission.
authors.affiliation: MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Boucrot
authors.forename: Adi
authors.initials: A
authors.lastname: Pick
authors.forename: Gamze
authors.initials: G
authors.lastname: Çamdere
authors.forename: Nicole
authors.initials: N
authors.lastname: Liska
authors.forename: Emma
authors.initials: E
authors.lastname: Evergren
authors.forename: Harvey T
authors.initials: HT
authors.lastname: McMahon
authors.forename: Michael M
authors.initials: MM
authors.lastname: Kozlov
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007425:Intracellular Membranes / Q000737:chemistry* / Q000378:metabolism*; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D017434:Protein Structure, Tertiary
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D008081:Liposomes; D008565:Membrane Proteins