| Autor: |
Chen A; Department of Biochemistry, University of Toronto, Toronto, ON, Canada., Ulloa Severino L; Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, Toronto, ON, Canada., Panagiotou TC; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada., Moraes TF; Department of Biochemistry, University of Toronto, Toronto, ON, Canada., Yuen DA; Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, Toronto, ON, Canada., Lavoie BD; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada., Wilde A; Department of Biochemistry, University of Toronto, Toronto, ON, Canada. andrew.wilde@utoronto.ca.; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada. andrew.wilde@utoronto.ca. |
| Abstrakt: |
During cytokinesis, the actin cytoskeleton is partitioned into two spatially distinct actin isoform specific networks: a β-actin network that generates the equatorial contractile ring, and a γ-actin network that localizes to the cell cortex. Here we demonstrate that the opposing regulation of the β- and γ-actin networks is required for successful cytokinesis. While activation of the formin DIAPH3 at the cytokinetic furrow underlies β-actin filament production, we show that the γ-actin network is specifically depleted at the cell poles through the localized deactivation of the formin DIAPH1. During anaphase, CLIP170 is delivered by astral microtubules and displaces IQGAP1 from DIAPH1, leading to formin autoinhibition, a decrease in cortical stiffness and localized membrane blebbing. The contemporaneous production of a β-actin contractile ring at the cell equator and loss of γ-actin from the poles is required to generate a stable cytokinetic furrow and for the completion of cell division. |
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