National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R01 GM073791
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
F31 GM148048
米国
引用
ジャーナル: Nat Commun / 年: 2023 タイトル: Mechanism of synergistic activation of Arp2/3 complex by cortactin and WASP-family proteins. 著者: Fred E Fregoso / Malgorzata Boczkowska / Grzegorz Rebowski / Peter J Carman / Trevor van Eeuwen / Roberto Dominguez / 要旨: Cortactin coactivates Arp2/3 complex synergistically with WASP-family nucleation-promoting factors (NPFs) and stabilizes branched networks by linking Arp2/3 complex to F-actin. It is poorly ...Cortactin coactivates Arp2/3 complex synergistically with WASP-family nucleation-promoting factors (NPFs) and stabilizes branched networks by linking Arp2/3 complex to F-actin. It is poorly understood how cortactin performs these functions. We describe the 2.89 Å resolution cryo-EM structure of cortactin's N-terminal domain (Cort) bound to Arp2/3 complex. Cortactin binds Arp2/3 complex through an inverted Acidic domain (D20-V29), which targets the same site on Arp3 as the Acidic domain of NPFs but with opposite polarity. Sequences N- and C-terminal to cortactin's Acidic domain do not increase its affinity for Arp2/3 complex but contribute toward coactivation with NPFs. Coactivation further increases with NPF dimerization and for longer cortactin constructs with stronger binding to F-actin. The results suggest that cortactin contributes to Arp2/3 complex coactivation with NPFs in two ways, by helping recruit the complex to F-actin and by stabilizing the short-pitch (active) conformation, which are both byproducts of cortactin's core function in branch stabilization.
詳細: The crystal structure of Arp2/3 complex at 2 angstrom resolution (PDB code: 1K8K) was used as the starting model for refinement of the Cort(1-76)-Arp2/3 complex structure. Multiple rounds of ...詳細: The crystal structure of Arp2/3 complex at 2 angstrom resolution (PDB code: 1K8K) was used as the starting model for refinement of the Cort(1-76)-Arp2/3 complex structure. Multiple rounds of refinement using the program Phenix 49 and model building in Coot led to a final model with excellent stereochemical parameters, good map-to-model correlation, and a map-to-model FSC of 3.35 angstroms.
最終 再構成
解像度のタイプ: BY AUTHOR / 解像度: 2.89 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 使用した粒子像数: 241506
初期 角度割当
タイプ: MAXIMUM LIKELIHOOD / ソフトウェア - 名称: cryoSPARC (ver. 4.0.0)