Movie
Controller
Structure viewers
About Yorodumi Papers
+Search query
-Structure paper
| Title | Arp2/3-mediated bidirectional actin assembly by SPIN90 dimers. |
|---|---|
| Journal, issue, pages | Nat Struct Mol Biol, Vol. 32, Issue 11, Page 2262-2271, Year 2025 |
| Publish date | Sep 15, 2025 |
 Authors | Tianyang Liu / Luyan Cao / Miroslav Mladenov / Guillaume Romet-Lemonne / Michael Way / Carolyn A Moores /   |
| PubMed Abstract | Branched actin networks nucleated by the Arp2/3 complex have critical roles in various cellular processes, from cell migration to intracellular transport. However, when activated by WISH/DIP/SPIN90- ...Branched actin networks nucleated by the Arp2/3 complex have critical roles in various cellular processes, from cell migration to intracellular transport. However, when activated by WISH/DIP/SPIN90-family proteins, Arp2/3 nucleates linear actin filaments. Here we found that human SPIN90 is a dimer that can nucleate bidirectional actin filaments. To understand the basis for this, we determined a 3-Å-resolution structure of human SPIN90-Arp2/3 complex nucleating actin filaments. Our structure shows that SPIN90 dimerizes through a three-helix bundle and interacts with two Arp2/3 complexes. Each SPIN90 molecule binds both Arp2/3 complexes to promote their activation. Our analysis demonstrates that single-filament nucleation by Arp2/3 is mechanistically more like branch formation than previously appreciated. The dimerization domain in SPIN90 orthologs is conserved in metazoans, suggesting that this mode of bidirectional nucleation is a common strategy to generate antiparallel actin filaments. |
 External links | Nat Struct Mol Biol / PubMed:40954369 / PubMed Central |
| Methods | EM (single particle) |
| Resolution | 3.0 Å |
| Structure data | EMDB-52580, PDB-9i2b: |
| Chemicals |  ChemComp-ADP:  ChemComp-MG: |
| Source |
|
 Keywords | CYTOSOLIC PROTEIN / Cytoskeleton / Branched actin network |
homo sapiens (human)
sus scrofa (pig)
amanita phalloides (death cap)