A nucleator arms race: cellular control of actin assembly

Nat Rev Mol Cell Biol. 2010 Apr;11(4):237-51. doi: 10.1038/nrm2867. Epub 2010 Mar 18.


For over a decade, the actin-related protein 2/3 (ARP2/3) complex, a handful of nucleation-promoting factors and formins were the only molecules known to directly nucleate actin filament formation de novo. However, the past several years have seen a surge in the discovery of mammalian proteins with roles in actin nucleation and dynamics. Newly recognized nucleation-promoting factors, such as WASP and SCAR homologue (WASH), WASP homologue associated with actin, membranes and microtubules (WHAMM), and junction-mediating regulatory protein (JMY), stimulate ARP2/3 activity at distinct cellular locations. Formin nucleators with additional biochemical and cellular activities have also been uncovered. Finally, the Spire, cordon-bleu and leiomodin nucleators have revealed new ways of overcoming the kinetic barriers to actin polymerization.

Publication types

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

MeSH terms

  • Actin Cytoskeleton / metabolism*
  • Actin-Related Protein 2-3 Complex / metabolism
  • Actins / metabolism*
  • Animals
  • Humans
  • Nuclear Proteins / physiology
  • Trans-Activators / physiology
  • Wiskott-Aldrich Syndrome Protein Family / physiology


  • Actin-Related Protein 2-3 Complex
  • Actins
  • JMY protein, human
  • Nuclear Proteins
  • Trans-Activators
  • Wiskott-Aldrich Syndrome Protein Family