Format

Send to

Choose Destination
J Cell Biol. 2019 Oct 7;218(10):3397-3414. doi: 10.1083/jcb.201807106. Epub 2019 Aug 13.

Apical polarity proteins recruit the RhoGEF Cysts to promote junctional myosin assembly.

Author information

1
Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada.
2
Department of Genetics, Harvard Medical School, Boston, MA.
3
RIKEN Center for Biosystems Dynamics Research, Minatojima-minamimachi, Kobe, Japan.
4
Department of Genetics, Harvard Medical School, Boston, MA perrimon@receptor.med.harvard.edu.
5
Howard Hughes Medical Institute, Harvard Medical School, Boston, MA.
6
Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada u.tepass@utoronto.ca.
#
Contributed equally

Abstract

The spatio-temporal regulation of small Rho GTPases is crucial for the dynamic stability of epithelial tissues. However, how RhoGTPase activity is controlled during development remains largely unknown. To explore the regulation of Rho GTPases in vivo, we analyzed the Rho GTPase guanine nucleotide exchange factor (RhoGEF) Cysts, the Drosophila orthologue of mammalian p114RhoGEF, GEF-H1, p190RhoGEF, and AKAP-13. Loss of Cysts causes a phenotype that closely resembles the mutant phenotype of the apical polarity regulator Crumbs. This phenotype can be suppressed by the loss of basolateral polarity proteins, suggesting that Cysts is an integral component of the apical polarity protein network. We demonstrate that Cysts is recruited to the apico-lateral membrane through interactions with the Crumbs complex and Bazooka/Par3. Cysts activates Rho1 at adherens junctions and stabilizes junctional myosin. Junctional myosin depletion is similar in Cysts- and Crumbs-compromised embryos. Together, our findings indicate that Cysts is a downstream effector of the Crumbs complex and links apical polarity proteins to Rho1 and myosin activation at adherens junctions, supporting junctional integrity and epithelial polarity.

PMID:
31409654
PMCID:
PMC6781438
[Available on 2020-04-07]
DOI:
10.1083/jcb.201807106

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center