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Updated: Jul 8, 2026
10:52
Reconstitution of Basic Mitotic Spindles in Spherical Emulsion Droplets
Published on: August 13, 2016
Moesin controls cortical rigidity, cell rounding, and spindle morphogenesis during mitosis
Patricia Kunda1, Andrew E Pelling, Tao Liu
1MRC Laboratory of Molecular Cell Biology, UCL, Gower Street, London WC1E 6BT, United Kingdom.
Current Biology : CB
|January 22, 2008
Summary
Moesin protein activation drives cell rounding and cortical rigidity during mitosis. This process is essential for proper spindle morphogenesis and chromosome alignment in animal cells.
Area of Science:
- Cell Biology
- Molecular Biology
- Biophysics
Background:
- Animal cells undergo significant morphological changes during mitosis.
- The molecular mechanisms and functional importance of early mitotic cell shape changes are not fully understood.
- Moesin, a Drosophila ERM protein, links actin filaments to plasma membrane proteins upon activation.
Purpose of the Study:
- To identify the molecular mechanisms regulating early mitotic cell shape changes.
- To elucidate the role of Moesin in mitotic cell morphology and progression.
Main Methods:
- Investigated Moesin activation and its effects on cortical rigidity and cell rounding.
- Utilized RNA interference (RNAi) to assess Moesin's necessity in vivo.
- Experimentally activated Moesin in interphase cells to test sufficiency.
Main Results:
- Moesin activation upon mitotic entry is necessary for increased cortical rigidity and cell rounding.
- Artificial Moesin activation induced cell rounding and rigidity independently of Myosin II.
- Moesin depletion (RNAi) impaired spindle morphogenesis and chromosome alignment.
- Spindle defects in Moesin-depleted cells were rescued by external cortical tension restoration.
Conclusions:
- Moesin activity changes during mitosis establish a stiff, rounded cortex at metaphase and promote polar relaxation at anaphase.
- Moesin-induced cortical rigidity is crucial for spindle morphogenesis and accurate chromosome segregation.
- Dynamic changes in cortical architecture, mediated by Moesin, are vital for mitosis in animal cells.
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