title: Coronin 1B antagonizes cortactin and remodels Arp2/3-containing actin branches in lamellipodia.
abstract: The dendritic actin network generated by the Arp2/3 complex in lamellipodia underlies formation of protrusions, directional sensing, and migration. While the generation of this network is well studied, the mechanisms regulating network disassembly are poorly understood. We report that Coronin 1B disassembles Arp2/3-containing actin filament branches by inducing Arp2/3 dissociation. This activity is antagonized by Cortactin, a filament branch stabilizer. Consistent with this biochemical competition, depletion of both proteins partially rescues defects in lamellipodial dynamics observed upon depletion of either protein alone. Coronin 1B targets actin branches in a manner that is mutually exclusive with the Arp2/3 complex and alters the branch angle. We conclude that Coronin 1B replaces the Arp2/3 complex at actin filament branches as the dendritic network matures and drives the turnover of branched actin networks.
authors.affiliation: Department of Cell and Developmental Biology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7295, USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Cai
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Makhov
authors.forename: Dorothy A
authors.initials: DA
authors.lastname: Schafer
authors.forename: James E
authors.initials: JE
authors.lastname: Bear
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000378:metabolism; D051377:Actin-Related Protein 2 / Q000378:metabolism*; D051378:Actin-Related Protein 3 / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D051356:Cortactin / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology; D005347:Fibroblasts; D006801:Humans; D051379:Mice; D011554:Pseudopodia; D051381:Rats; D054378:Acetogenins
chemical_list: D015107:4-Butyrolactone; D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D000199:Actins; D051356:Cortactin; C438920:coronin acetogenin; D054378:Acetogenins
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