An actin nucleation mechanism mediated by Bni1 and profilin

Nat Cell Biol. 2002 Aug;4(8):626-31. doi: 10.1038/ncb834.

Abstract

Formins are required for cell polarization and cytokinesis, but do not have a defined biochemical activity. In Saccharomyces cerevisiae, formins and the actin-monomer-binding protein profilin are specifically required to assemble linear actin structures called 'actin cables'. These structures seem to be assembled independently of the Arp2/3 complex, the only well characterized cellular mediator of actin nucleation. Here, an activated yeast formin was purified and found to promote the nucleation of actin filaments in vitro. Formin-dependent actin nucleation was stimulated by profilin. Thus, formin and profilin mediate actin nucleation by an Arp2/3-independent mechanism. These findings suggest that distinct actin nucleation mechanisms may underlie the assembly of different actin cytoskeletal structures.

Publication types

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

MeSH terms

  • Actin-Related Protein 2
  • Actin-Related Protein 3
  • Actins / chemistry
  • Actins / genetics
  • Actins / metabolism*
  • Biopolymers / chemistry
  • Biopolymers / genetics
  • Biopolymers / metabolism
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cytoskeletal Proteins*
  • Cytoskeleton / metabolism
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • Microfilament Proteins*
  • Profilins
  • Protein Binding
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • ARP3 protein, S cerevisiae
  • Actin-Related Protein 2
  • Actin-Related Protein 3
  • Actins
  • Biopolymers
  • Bni1 protein, S cerevisiae
  • CDC3 protein, S cerevisiae
  • Cell Cycle Proteins
  • Cytoskeletal Proteins
  • Fungal Proteins
  • Microfilament Proteins
  • Profilins
  • Saccharomyces cerevisiae Proteins