Stanishneva-Konovalova Tatiana B, Kelley Charlotte F, Eskin Tania L, Messelaar Emily M, Wasserman Steven A, Sokolova Olga S, Rodal Avital A
Department of Bioengineering, Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia;
Rosenstiel Basic Medical Sciences Research Center, Department of Biology, Brandeis University, Waltham, MA 02453.
Proc Natl Acad Sci U S A. 2016 Sep 20;113(38):E5552-61. doi: 10.1073/pnas.1524412113. Epub 2016 Sep 6.
Membrane remodeling by Fes/Cip4 homology-Bin/Amphiphysin/Rvs167 (F-BAR) proteins is regulated by autoinhibitory interactions between their SRC homology 3 (SH3) and F-BAR domains. The structural basis of autoregulation, and whether it affects interactions of SH3 domains with other cellular ligands, remain unclear. Here we used single-particle electron microscopy to determine the structure of the F-BAR protein Nervous Wreck (Nwk) in both soluble and membrane-bound states. On membrane binding, Nwk SH3 domains do not completely dissociate from the F-BAR dimer, but instead shift from its concave surface to positions on either side of the dimer. Unexpectedly, along with controlling membrane binding, these autoregulatory interactions inhibit the ability of Nwk-SH3a to activate Wiskott-Aldrich syndrome protein (WASp)/actin related protein (Arp) 2/3-dependent actin filament assembly. In Drosophila neurons, Nwk autoregulation restricts SH3a domain-dependent synaptopod formation, synaptic growth, and actin organization. Our results define structural rearrangements in Nwk that control F-BAR-membrane interactions as well as SH3 domain activities, and suggest that these two functions are tightly coordinated in vitro and in vivo.
Fes/Cip4同源结构域-Bin/Amphiphysin/Rvs167（F-BAR）蛋白介导的膜重塑受其Src同源结构域3（SH3）和F-BAR结构域之间的自抑制相互作用调控。这种自调控的结构基础以及它是否影响SH3结构域与其他细胞配体的相互作用仍不清楚。在这里，我们使用单颗粒电子显微镜来确定F-BAR蛋白神经破坏蛋白（Nwk）在可溶性和膜结合状态下的结构。在膜结合时，Nwk的SH3结构域不会完全从F-BAR二聚体上解离，而是从其凹面转移到二聚体两侧的位置。出乎意料的是，除了控制膜结合外，这些自调控相互作用还抑制了Nwk-SH3a激活威斯科特-奥尔德里奇综合征蛋白（WASp）/肌动蛋白相关蛋白（Arp）2/3依赖性肌动蛋白丝组装的能力。在果蝇神经元中，Nwk的自调控限制了SH3a结构域依赖性突触足形成、突触生长和肌动蛋白组织。我们的结果确定了Nwk中的结构重排，这些重排控制F-BAR与膜的相互作用以及SH3结构域的活性，并表明这两种功能在体外和体内都紧密协调。
