title: Electron tomography reveals a flared morphology on growing microtubule ends.
abstract: Microtubules (MTs) exhibit dynamic instability, alternating between phases of growth and shortening, mostly at their uncapped plus ends. Based on results from cryo-electron microscopy it was proposed that growing MTs display mainly curved sheets and blunt ends; during depolymerisation curled 'ramshorns' predominate. Observations of MTs in mitotic cells have suggested that the situation in vivo differs from that in vitro, but so far, a clear comparison between in vivo and in vitro results has not been possible because MT end structures could not be correlated directly with the dynamic state of that particular MT. Here we combine light microscopy and electron tomography (ET) to show that growing MT plus ends in the fission yeast Schizosaccharomyces pombe display predominantly a flared morphology. This indicates that MT polymerisation in vivo and in vitro can follow different paths.
authors.affiliation: European Molecular Biology Laboratories, Cell Biology and Biophysics Program, D-69117 Heidelberg, Germany. johanna.hoog@path.ox.ac.uk
authors.forename: Johanna L
authors.initials: JL
authors.lastname: Höög
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Huisman
authors.forename: Zsofia
authors.initials: Z
authors.lastname: Sebö-Lemke
authors.forename: Linda
authors.initials: L
authors.lastname: Sandblad
authors.forename: J Richard
authors.initials: JR
authors.lastname: McIntosh
authors.forename: Claude
authors.initials: C
authors.lastname: Antony
authors.forename: Damian
authors.initials: D
authors.lastname: Brunner
mesh_terms: D020285:Cryoelectron Microscopy; D055032:Electron Microscope Tomography / Q000379:methods*; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000737:chemistry / Q000166:cytology; D014404:Tubulin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D011993:Recombinant Fusion Proteins; D014404:Tubulin