Regulation of actin filament dynamics by actin depolymerizing factor/cofilin and actin-interacting protein 1: new blades for twisted filaments.
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.
Ono
Shoichiro
S
Department of Pathology, Emory University, Atlanta, Georgia 30322, USA. sono@emory.edu
D008841:Actin Cytoskeleton / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D051339:Actin Depolymerizing Factors; D000818:Animals; D001665:Binding Sites; D017124:Conserved Sequence; D051345:Destrin; D006801:Humans; D008840:Microfilament Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D011487:Protein Conformation
D051339:Actin Depolymerizing Factors; C495824:DSTN protein, human; D051345:Destrin; D008840:Microfilament Proteins; C115237:actin interacting protein 1