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Prophase-Specific Perinuclear Actin Coordinates Centrosome Separation and Positioning to Ensure Accurate Chromosome
Tom Stiff1, Fabio R Echegaray-Iturra1, Harry J Pink1
1Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN19RQ, UK.
Cell Reports
|May 28, 2020
Summary
Centrosome positioning relies on microtubule and actin dynamics, guided by the nucleus. Disrupting the linker of nucleoskeleton and cytoskeleton (LINC) complex interactions with actin causes chromosome segregation errors.
Area of Science:
- Cell Biology
- Molecular Biology
- Cytoskeleton Dynamics
Background:
- Centrosome separation is crucial for cell division and requires balanced forces.
- The kinesin Eg5 is a known driver of separation, but opposing forces are less understood.
Purpose of the Study:
- To investigate the forces antagonizing centrosome separation and the mechanism of centrosome positioning.
- To identify the role of nuclear-actin interactions in coordinating centrosome orientation.
Main Methods:
- Experimental manipulation of candidate proteins involved in centrosome separation.
- Microscopy to observe microtubule and actin polymerization dynamics.
- Analysis of the linker of nucleoskeleton and cytoskeleton (LINC) complex interactions.
Main Results:
- Centrosome separation is reversible and involves congress toward the nucleus.
- Both microtubule and actin polymerization are essential for centrosome positioning.
- Perinuclear actin structures interact with centrosomal microtubules.
- Disruption of LINC complex-actin interactions impairs positioning and increases chromosome segregation errors.
Conclusions:
- The cell nucleus provides geometrical cues for spindle pole orientation before nuclear envelope breakdown.
- Actin and microtubule cytoskeletons, coordinated by the LINC complex, play a critical role in centrosome positioning and accurate chromosome segregation.
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