Polarization of the C. elegans embryo by RhoGAP-mediated exclusion of PAR-6 from cell contacts

Science. 2008 Jun 27;320(5884):1771-4. doi: 10.1126/science.1156063.


Early embryos of some metazoans polarize radially to facilitate critical patterning events such as gastrulation and asymmetric cell division; however, little is known about how radial polarity is established. Early embryos of Caenorhabditis elegans polarize radially when cell contacts restrict the polarity protein PAR-6 to contact-free cell surfaces, where PAR-6 regulates gastrulation movements. We have identified a Rho guanosine triphosphatase activating protein (RhoGAP), PAC-1, which mediates C. elegans radial polarity and gastrulation by excluding PAR-6 from contacted cell surfaces. We show that PAC-1 is recruited to cell contacts, and we suggest that PAC-1 controls radial polarity by restricting active CDC-42 to contact-free surfaces, where CDC-42 binds and recruits PAR-6. Thus, PAC-1 provides a dynamic molecular link between cell contacts and PAR proteins that polarizes embryos radially.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Patterning
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Cell Communication*
  • Cell Membrane / metabolism*
  • Cell Polarity*
  • Cytoplasm / metabolism
  • Embryo, Nonmammalian / cytology*
  • Embryo, Nonmammalian / metabolism
  • Embryonic Development
  • GTPase-Activating Proteins / metabolism*
  • Gastrulation
  • Molecular Sequence Data
  • Protein Serine-Threonine Kinases
  • Protein Structure, Tertiary
  • Recombinant Fusion Proteins / metabolism
  • cdc42 GTP-Binding Protein / metabolism


  • Caenorhabditis elegans Proteins
  • GTPase-Activating Proteins
  • PAC-1 protein, C elegans
  • Recombinant Fusion Proteins
  • par-6 protein, C elegans
  • rho GTPase-activating protein
  • PAR-3 protein, C elegans
  • Protein Serine-Threonine Kinases
  • cdc42 GTP-Binding Protein

Associated data

  • GENBANK/EU752496