Revolving movement of a dynamic cluster of actin filaments during mitosis

Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, Japan.
The Journal of Cell Biology (Impact Factor: 9.83). 10/2010; 191(3):453-62. DOI: 10.1083/jcb.201007136
Source: PubMed


The actin cytoskeleton undergoes rapid changes in its architecture during mitosis. Here, we demonstrate novel actin assembly dynamics in M phase. An amorphous cluster of actin filaments appears during prometaphase, revolves horizontally along the cell cortex at a constant angular speed, and fuses into the contractile ring after three to four revolutions. Cdk1 activity is required for the formation of this mitotic actin cluster and its revolving movement. Rapid turnover of actin in the filaments takes place everywhere in the cluster and is also required for its cluster rotation during mitosis. Knockdown of Arp3, a component of the actin filament-nucleating Arp2/3 complex, inhibits the formation of the mitotic actin cluster without affecting other actin structures. These results identify Arp2/3 complex as a key factor in the generation of the dynamic actin cluster during mitosis.

Download full-text


Available from: Kazuhiro Aoki, Oct 03, 2015
20 Reads
  • Source
    • "Myosin 2 is enriched at the spindle poles and repositions the spindle to the cortex by physically pulling on the intracellular actin network (Schuh and Ellenberg 2008). Dynamic, Arp2/3 nucleated cytoplasmic actin structures have also been observed during symmetric divisions of cultured cells (Mitsushima et al. 2010) where they may also influence the orientation of the spindle (Fink et al. 2011). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Many cell types undergo dramatic changes in shape throughout the cell cycle. For individual cells, a tight control of cell shape is crucial during cell division, but also in interphase, for example during cell migration. Moreover, cell cycle-related cell shape changes have been shown to be important for tissue morphogenesis in a number of developmental contexts. Cell shape is the physical result of cellular mechanical properties and of the forces exerted on the cell. An understanding of the causes and repercussions of cell shape changes thus requires knowledge of both the molecular regulation of cellular mechanics and how specific changes in cell mechanics in turn effect global shape changes. In this chapter, we provide an overview of the current knowledge on the control of cell morphology, both in terms of general cell mechanics and specifically during the cell cycle.
    Results and problems in cell differentiation 01/2011; 53:31-73. DOI:10.1007/978-3-642-19065-0_3
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The response of cells to forces is essential for tissue morphogenesis and homeostasis. This response has been extensively investigated in interphase cells, but it remains unclear how forces affect dividing cells. We used a combination of micro-manipulation tools on human dividing cells to address the role of physical parameters of the micro-environment in controlling the cell division axis, a key element of tissue morphogenesis. We found that forces applied on the cell body direct spindle orientation during mitosis. We further show that external constraints induce a polarization of dynamic subcortical actin structures that correlate with spindle movements. We propose that cells divide according to cues provided by their mechanical micro-environment, aligning daughter cells with the external force field.
    Nature Cell Biology 06/2011; 13(7):771-8. DOI:10.1038/ncb2269 · 19.68 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Both symmetric and asymmetric divisions rely on alignment of the mitotic spindle with cues from the environment. A study now shows that mitotic spindles find their position by reading the map of forces that load-bearing retraction fibres exert on the cell body.
    Nature Cell Biology 07/2011; 13(7):736-8. DOI:10.1038/ncb0711-736 · 19.68 Impact Factor
Show more