title: Single-molecule imaging of a three-component ordered actin disassembly mechanism.
abstract: The mechanisms by which cells destabilize and rapidly disassemble filamentous actin networks have remained elusive; however, Coronin, Cofilin and AIP1 have been implicated in this process. Here using multi-wavelength single-molecule fluorescence imaging, we show that mammalian Cor1B, Cof1 and AIP1 work in concert through a temporally ordered pathway to induce highly efficient severing and disassembly of actin filaments. Cor1B binds to filaments first, and dramatically accelerates the subsequent binding of Cof1, leading to heavily decorated, stabilized filaments. Cof1 in turn recruits AIP1, which rapidly triggers severing and remains bound to the newly generated barbed ends. New growth at barbed ends generated by severing was blocked specifically in the presence of all three proteins. This activity enabled us to reconstitute and directly visualize single actin filaments being rapidly polymerized by formins at their barbed ends while simultanteously being stochastically severed and capped along their lengths, and disassembled from their pointed ends.
authors.affiliation: Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South street, Waltham, Massachusetts 02454, USA.
authors.forename: Silvia
authors.initials: S
authors.lastname: Jansen
authors.affiliation: Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South street, Waltham, Massachusetts 02454, USA.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Collins
authors.affiliation: Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South street, Waltham, Massachusetts 02454, USA.
authors.forename: Samantha M
authors.initials: SM
authors.lastname: Chin
authors.affiliation: Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South street, Waltham, Massachusetts 02454, USA.
authors.forename: Casey A
authors.initials: CA
authors.lastname: Ydenberg
authors.affiliation: Department of Biochemistry, Brandeis University, 415 South street, Waltham, Massachusetts 02454, USA.
authors.forename: Jeff
authors.identifier: 0000000179103421
authors.initials: J
authors.lastname: Gelles
authors.affiliation: Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South street, Waltham, Massachusetts 02454, USA.
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Goode
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000818:Animals; D051338:Cofilin 1 / Q000378:metabolism*; D004926:Escherichia coli; D006801:Humans; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism*; D008856:Microscopy, Fluorescence / Q000379:methods; D011817:Rabbits; D020703:ras GTPase-Activating Proteins / Q000378:metabolism*
chemical_list: D051338:Cofilin 1; C561450:Dab2ip protein, mouse; D008840:Microfilament Proteins; D020703:ras GTPase-Activating Proteins; C072061:coronin proteins