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-Structure paper
Title | Cortactin stabilizes actin branches by bridging activated Arp2/3 to its nucleated actin filament. |
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Journal, issue, pages | Nat Struct Mol Biol, Vol. 31, Issue 5, Page 801-809, Year 2024 |
Publish date | Jan 24, 2024 |
Authors | Tianyang Liu / Luyan Cao / Miroslav Mladenov / Antoine Jegou / Michael Way / Carolyn A Moores / |
PubMed Abstract | Regulation of the assembly and turnover of branched actin filament networks nucleated by the Arp2/3 complex is essential during many cellular processes, including cell migration and membrane ...Regulation of the assembly and turnover of branched actin filament networks nucleated by the Arp2/3 complex is essential during many cellular processes, including cell migration and membrane trafficking. Cortactin is important for actin branch stabilization, but the mechanism by which this occurs is unclear. Given this, we determined the structure of vertebrate cortactin-stabilized Arp2/3 actin branches using cryogenic electron microscopy. We find that cortactin interacts with the new daughter filament nucleated by the Arp2/3 complex at the branch site, rather than the initial mother actin filament. Cortactin preferentially binds activated Arp3. It also stabilizes the F-actin-like interface of activated Arp3 with the first actin subunit of the new filament, and its central repeats extend along successive daughter-filament subunits. The preference of cortactin for activated Arp3 explains its retention at the actin branch and accounts for its synergy with other nucleation-promoting factors in regulating branched actin network dynamics. |
External links | Nat Struct Mol Biol / PubMed:38267598 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.2 - 3.8 Å |
Structure data | EMDB-17553: Cryo-EM structure of cortactin-stabilized Arp2/3 complex nucleated actin branches-Daughter filament consensus map EMDB-17554: Cryo-EM structure of cortactin-stabilized Arp2/3 nucleated actin branches-Local refined map on Arp2/3 complex EMDB-17555: Cryo-EM structure of cortactin-stabilized Arp2/3-complex nucleated actin branches-Local refined map on the daughter filament and cortactin density EMDB-17556: Cryo-EM structure of cortactin-stabilized Arp2/3-complex nucleated actin branches-Local refined map on capping protein EMDB-17557: Cryo-EM structure of cortactin-stabilized Arp2/3-complex nucleated actin branches-Local refined map on mother filament EMDB-17558, PDB-8p94: |
Chemicals | ChemComp-ADP: ChemComp-MG: |
Source |
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Keywords | CONTRACTILE PROTEIN / Complex |