title: Endocytic membrane fusion and buckling-induced microtubule severing mediate cell abscission.
abstract: Cytokinesis and abscission are complicated events that involve changes in membrane transport and cytoskeleton organization. We have used the combination of time-lapse microscopy and correlative high-resolution 3D tomography to analyze the regulation and spatio-temporal remodeling of endosomes and microtubules during abscission. We show that abscission is driven by the formation of a secondary ingression within the intracellular bridge connecting two daughter cells. The initiation and expansion of this secondary ingression requires recycling endosome fusion with the furrow plasma membrane and nested central spindle microtubule severing. These changes in endosome fusion and microtubule reorganization result in increased intracellular bridge plasma membrane dynamics and abscission. Finally, we show that central spindle microtubule reorganization is driven by localized microtubule buckling and breaking, rather than by spastin-dependent severing. Our results provide a new mechanism for mediation and regulation of the abscission step of cytokinesis.
authors.affiliation: Department of Cell and Developmental Biology, University of Colorado Denver, Aurora, CO 80045, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Schiel
authors.forename: Kristin
authors.initials: K
authors.lastname: Park
authors.forename: Mary K
authors.initials: MK
authors.lastname: Morphew
authors.forename: Evan
authors.initials: E
authors.lastname: Reid
authors.forename: Andreas
authors.initials: A
authors.lastname: Hoenger
authors.forename: Rytis
authors.initials: R
authors.lastname: Prekeris
mesh_terms: D048749:Cytokinesis / Q000235:genetics / Q000502:physiology*; D011992:Endosomes / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism; D008561:Membrane Fusion / Q000235:genetics / Q000502:physiology*; D016253:Microscopy, Immunoelectron; D008870:Microtubules / Q000378:metabolism*; D050683:R-SNARE Proteins / Q000378:metabolism; D034622:RNA Interference
chemical_list: C491731:IKBKG protein, human; D050683:R-SNARE Proteins; C112938:VAMP8 protein, human; D051550:I-kappa B Kinase