title: Ablation of PRC1 by small interfering RNA demonstrates that cytokinetic abscission requires a central spindle bundle in mammalian cells, whereas completion of furrowing does not.
abstract: The temporal and spatial regulation of cytokinesis requires an interaction between the anaphase mitotic spindle and the cell cortex. However, the relative roles of the spindle asters or the central spindle bundle are not clear in mammalian cells. The central spindle normally serves as a platform to localize key regulators of cell cleavage, including passenger proteins. Using time-lapse and immunofluorescence analysis, we have addressed the consequences of eliminating the central spindle by ablation of PRC1, a microtubule bundling protein that is critical to the formation of the central spindle. Without a central spindle, the asters guide the equatorial cortical accumulation of anillin and actin, and of the passenger proteins, which organize into a subcortical ring in anaphase. Furrowing goes to completion, but abscission to create two daughter cells fails. We conclude the central spindle bundle is required for abscission but not for furrowing in mammalian cells.
authors.affiliation: Institut de Biologie Structurale J-P Ebel (Commissariat à l'Energie Atomique-Centre National de la Recherche Scientifique-Université Joseph Fournier), 38027 Grenoble Cedex 1, France.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Mollinari
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Kleman
authors.forename: Yasmina
authors.initials: Y
authors.lastname: Saoudi
authors.forename: Sandra A
authors.initials: SA
authors.lastname: Jablonski
authors.forename: Julien
authors.initials: J
authors.lastname: Perard
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Yen
authors.forename: Robert L
authors.initials: RL
authors.lastname: Margolis
mesh_terms: D000199:Actins / Q000235:genetics; D000705:Anaphase; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000235:genetics / Q000502:physiology*; D003285:Contractile Proteins / Q000235:genetics; D048749:Cytokinesis; D003599:Cytoskeleton / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D018715:Microscopy, Video; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism; D008941:Spindle Apparatus; D013997:Time Factors
chemical_list: D000199:Actins; D018797:Cell Cycle Proteins; D003285:Contractile Proteins; C116662:PRC1 protein, human; D034741:RNA, Small Interfering; C095886:anillin