title: Curvature-induced expulsion of actomyosin bundles during cytokinetic ring contraction.
abstract: Many eukaryotes assemble a ring-shaped actomyosin network that contracts to drive cytokinesis. Unlike actomyosin in sarcomeres, which cycles through contraction and relaxation, the cytokinetic ring disassembles during contraction through an unknown mechanism. Here we find inSchizosaccharomyces japonicusandSchizosaccharomyces pombethat, during actomyosin ring contraction, actin filaments associated with actomyosin rings are expelled as micron-scale bundles containing multiple actomyosin ring proteins. Using functional isolated actomyosin rings we show that expulsion of actin bundles does not require continuous presence of cytoplasm. Strikingly, mechanical compression of actomyosin rings results in expulsion of bundles predominantly at regions of high curvature. Our work unprecedentedly reveals that the increased curvature of the ring itself promotes its disassembly. It is likely that such a curvature-induced mechanism may operate in disassembly of other contractile networks.
authors.affiliation: Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom.
authors.forename: Junqi
authors.initials: J
authors.lastname: Huang
authors.affiliation: Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom.
authors.forename: Ting Gang
authors.initials: TG
authors.lastname: Chew
authors.affiliation: Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom.
authors.forename: Ying
authors.initials: Y
authors.lastname: Gu
authors.affiliation: Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom.
authors.forename: Saravanan
authors.initials: S
authors.lastname: Palani
authors.affiliation: Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom.
authors.forename: Anton
authors.initials: A
authors.lastname: Kamnev
authors.affiliation: Department of Physics, Lawrence University, Appleton, United States.
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Martin
authors.affiliation: Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Carter
authors.affiliation: Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom.
authors.forename: Robert Anthony
authors.identifier: 0000-0002-0004-7832
authors.initials: RA
authors.lastname: Cross
authors.affiliation: Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom.
authors.forename: Snezhana
authors.initials: S
authors.lastname: Oliferenko
authors.affiliation: Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom.
authors.forename: Mohan K
authors.identifier: 0000-0002-1292-8602
authors.initials: MK
authors.lastname: Balasubramanian
mesh_terms: D008841:Actin Cytoskeleton / Q000235:genetics* / Q000378:metabolism; D000199:Actins / Q000235:genetics; D000205:Actomyosin / Q000737:chemistry / Q000378:metabolism*; D048749:Cytokinesis / Q000235:genetics*; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D009119:Muscle Contraction / Q000235:genetics* / Q000502:physiology; D012518:Sarcomeres / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics / Q000502:physiology
chemical_list: D000199:Actins; D000205:Actomyosin
keywords: S. pombe; Schizosaccharomyces japonicus; Schizosaccharomyces pombe; actomyosin ring; cell biology; curvature; cytokinesis