Arp2/3 is a negative regulator of growth cone translocation

Neuron. 2004 Jul 8;43(1):81-94. doi: 10.1016/j.neuron.2004.05.015.


Arp2/3 is an actin binding complex that is enriched in the peripheral lamellipodia of fibroblasts, where it forms a network of short, branched actin filaments, generating the protrusive force that extends lamellipodia and drives fibroblast motility. Although it has been assumed that Arp2/3 would play a similar role in growth cones, our studies indicate that Arp2/3 is enriched in the central, not the peripheral, region of growth cones and that the growth cone periphery contains few branched actin filaments. Arp2/3 inhibition in fibroblasts severely disrupts actin organization and membrane protrusion. In contrast, Arp2/3 inhibition in growth cones minimally affects actin organization and does not inhibit lamellipodia protrusion or de novo filopodia formation. Surprisingly, Arp2/3 inhibition significantly enhances axon elongation and causes defects in growth cone guidance. These results indicate that Arp2/3 is a negative regulator of growth cone translocation.

Publication types

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

MeSH terms

  • Actin Cytoskeleton / metabolism*
  • Actin-Related Protein 2
  • Actin-Related Protein 3
  • Amino Acid Sequence / genetics
  • Animals
  • Animals, Newborn
  • Cell Differentiation / genetics
  • Cell Movement / genetics*
  • Cells, Cultured
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / physiology*
  • Feedback, Physiological / genetics
  • Fetus
  • Green Fluorescent Proteins
  • Growth Cones / metabolism*
  • Growth Cones / ultrastructure
  • Luminescent Proteins
  • Macromolecular Substances
  • Mice
  • Microtubules / metabolism
  • Nervous System / cytology
  • Nervous System / embryology*
  • Nervous System / metabolism
  • Protein Binding / genetics
  • Protein Structure, Tertiary / genetics
  • Pseudopodia / metabolism
  • Pseudopodia / ultrastructure


  • Actin-Related Protein 2
  • Actin-Related Protein 3
  • Actr2 protein, mouse
  • Actr3 protein, mouse
  • Cytoskeletal Proteins
  • Luminescent Proteins
  • Macromolecular Substances
  • Green Fluorescent Proteins