Format

Send to

Choose Destination
Development. 2006 Sep;133(18):3507-16. Epub 2006 Aug 9.

CDC-42 and RHO-1 coordinate acto-myosin contractility and PAR protein localization during polarity establishment in C. elegans embryos.

Author information

1
Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany. schonegg@mpi-cbg.de

Abstract

In C. elegans one-cell embryos, polarity is conventionally defined along the anteroposterior axis by the segregation of partitioning-defective (PAR) proteins into anterior (PAR-3, PAR-6) and posterior (PAR-1, PAR-2) cortical domains. The establishment of PAR asymmetry is coupled with acto-myosin cytoskeleton rearrangements. The small GTPases RHO-1 and CDC-42 are key players in cytoskeletal remodeling and cell polarity in a number of different systems. We investigated the roles of these two GTPases and the RhoGEF ECT-2 in polarity establishment in C. elegans embryos. We show that CDC-42 is required to remove PAR-2 from the cortex at the end of meiosis and to localize PAR-6 to the cortex. By contrast, RHO-1 activity is required to facilitate the segregation of CDC-42 and PAR-6 to the anterior. Loss of RHO-1 activity causes defects in the early organization of the myosin cytoskeleton but does not inhibit segregation of myosin to the anterior. We therefore propose that RHO-1 couples the polarization of the acto-myosin cytoskeleton with the proper segregation of CDC-42, which, in turn, localizes PAR-6 to the anterior cortex.

PMID:
16899536
DOI:
10.1242/dev.02527
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center