Regulation of actin filament dynamics by actin depolymerizing factor/cofilin and actin-interacting protein 1: new blades for twisted filaments

Biochemistry. 2003 Nov 25;42(46):13363-70. doi: 10.1021/bi034600x.


Actin depolymerizing factor (ADF)/cofilin enhances turnover of actin filaments by severing and depolymerizing filaments. A number of proteins functionally interact with ADF/cofilin to modulate the dynamics of actin filaments. Actin-interacting protein 1 (AIP1) has emerged as a conserved WD-repeat protein that specifically enhances ADF/cofilin-induced actin dynamics. Interaction of AIP1 with actin was originally characterized by a yeast two-hybrid system. However, biochemical studies revealed its unique activity on ADF/cofilin-bound actin filaments. AIP1 alone has negligible effects on actin filament dynamics, whereas in the presence of ADF/cofilin, AIP1 enhances filament fragmentation by capping ends of severed filaments. Studies in model organisms demonstrated that AIP1 genetically interacts with ADF/cofilin and participates in several actin-dependent cellular events. The crystal structure of AIP1 revealed its unique structure with two seven-bladed beta-propeller domains. Thus, AIP1 is a new class of actin regulatory proteins that selectively enhances ADF/cofilin-dependent actin filament dynamics.

Publication types

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

MeSH terms

  • Actin Cytoskeleton / chemistry*
  • Actin Cytoskeleton / metabolism*
  • Actin Cytoskeleton / ultrastructure
  • Actin Depolymerizing Factors
  • Animals
  • Binding Sites
  • Conserved Sequence
  • Destrin
  • Humans
  • Microfilament Proteins / chemistry
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism*
  • Models, Molecular
  • Protein Conformation


  • Actin Depolymerizing Factors
  • DSTN protein, human
  • Destrin
  • Microfilament Proteins
  • actin interacting protein 1