Three C. elegans Rac proteins and several alternative Rac regulators control axon guidance, cell migration and apoptotic cell phagocytosis

Development. 2001 Nov;128(22):4475-88.


The Caenorhabditis elegans genome contains three rac-like genes, ced-10, mig-2, and rac-2. We report that ced-10, mig-2 and rac-2 act redundantly in axon pathfinding: inactivating one gene had little effect, but inactivating two or more genes perturbed both axon outgrowth and guidance. mig-2 and ced-10 also have redundant functions in some cell migrations. By contrast, ced-10 is uniquely required for cell-corpse phagocytosis, and mig-2 and rac-2 have only subtle roles in this process. Rac activators are also used differentially. The UNC-73 Trio Rac GTP exchange factor affected all Rac pathways in axon pathfinding and cell migration but did not affect cell-corpse phagocytosis. CED-5 DOCK180, which acts with CED-10 Rac in cell-corpse phagocytosis, acted with MIG-2 but not CED-10 in axon pathfinding. Thus, distinct regulatory proteins modulate Rac activation and function in different developmental processes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apoptosis
  • Axons / physiology*
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Cell Differentiation
  • Cell Movement*
  • GTP-Binding Proteins / genetics
  • GTP-Binding Proteins / metabolism
  • Helminth Proteins / genetics
  • Helminth Proteins / metabolism
  • Models, Biological
  • Molecular Sequence Data
  • Multigene Family
  • Nerve Tissue Proteins / metabolism
  • Nervous System / embryology
  • Phagocytosis*
  • Sequence Homology, Amino Acid
  • rac GTP-Binding Proteins / genetics
  • rac GTP-Binding Proteins / metabolism*


  • CED-10 protein, C elegans
  • Caenorhabditis elegans Proteins
  • Helminth Proteins
  • Nerve Tissue Proteins
  • UNC-73 protein, C elegans
  • GTP-Binding Proteins
  • Mig-2 protein, C elegans
  • rac2 GTP-binding protein
  • rac GTP-Binding Proteins