Format

Send to

Choose Destination
Dev Cell. 2015 Mar 9;32(5):604-16. doi: 10.1016/j.devcel.2015.01.012. Epub 2015 Feb 19.

Ect2/Pbl acts via Rho and polarity proteins to direct the assembly of an isotropic actomyosin cortex upon mitotic entry.

Author information

1
MRC Laboratory of Molecular Cell Biology, UCL, Gower Street, London WC1E 6BT, UK; Graduate Program in Areas of Basic and Applied Biology (GABBA), University of Porto, 4200-465 Porto, Portugal.
2
MRC Laboratory of Molecular Cell Biology, UCL, Gower Street, London WC1E 6BT, UK.
3
MRC Laboratory of Molecular Cell Biology, UCL, Gower Street, London WC1E 6BT, UK. Electronic address: b.baum@ucl.ac.uk.

Abstract

Entry into mitosis is accompanied by profound changes in cortical actomyosin organization. Here, we delineate a pathway downstream of the RhoGEF Pbl/Ect2 that directs this process in a model epithelium. Our data suggest that the release of Pbl/Ect2 from the nucleus at mitotic entry drives Rho-dependent activation of Myosin-II and, in parallel, induces a switch from Arp2/3 to Diaphanous-mediated cortical actin nucleation that depends on Cdc42, aPKC, and Par6. At the same time, the mitotic relocalization of these apical protein complexes to more lateral cell surfaces enables Cdc42/aPKC/Par6 to take on a mitosis-specific function-aiding the assembly of a relatively isotropic metaphase cortex. Together, these data reveal how the repolarization and remodeling of the actomyosin cortex are coordinated upon entry into mitosis to provide cells with the isotropic and rigid form they need to undergo faithful chromosome segregation and division in a crowded tissue environment.

PMID:
25703349
PMCID:
PMC4359025
DOI:
10.1016/j.devcel.2015.01.012
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center