title: Actin filament elongation in Arp2/3-derived networks is controlled by three distinct mechanisms.
abstract: Spatial and temporal control of actin filament barbed end elongation is crucial for force generation by actin networks. In this study, genetics, cell biology, and biochemistry were used to reveal three complementary mechanisms that regulate actin filament barbed end elongation in Arp2/3-derived networks. Aip1 inhibits elongation of aged ADP-actin filaments decorated with cofilin and, together with capping protein (CP), maintains a high level of assembly-competent actin species. We identified Abp1 and Aim3 as two additional proteins that work together to inhibit barbed end elongation. Abp1/Aim3 collaborates with CP to control elongation of newly assembled ATP-actin filaments to organize filament polarity within actin networks. Thus, three distinct mechanisms control filament elongation in different regions of Arp2/3 networks, maintaining pools of assembly-competent actin species while ensuring proper filament polarity and facilitating force production.
authors: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA.
authors: Alphée
authors: A
authors: Michelot
authors: Alexandre
authors: A
authors: Grassart
authors: Voytek
authors: V
authors: Okreglak
authors: Michael
authors: M
authors: Costanzo
authors: Charles
authors: C
authors: Boone
authors: David G
authors: DG
authors: Drubin
mesh_terms: D051344:Actin Capping Proteins / Q000378:metabolism; D008841:Actin Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure; D051339:Actin Depolymerizing Factors / Q000378:metabolism; D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D008840:Microfilament Proteins / Q000378:metabolism; D048328:Potoroidae; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D020703:ras GTPase-Activating Proteins / Q000378:metabolism*
chemical_list: C062612:ABP1 protein, S cerevisiae; D051344:Actin Capping Proteins; D051339:Actin Depolymerizing Factors; D051376:Actin-Related Protein 2-3 Complex; D008840:Microfilament Proteins; D029701:Saccharomyces cerevisiae Proteins; D020703:ras GTPase-Activating Proteins