article published yes Florian Fäßler author 404F5528-F248-11E8-B48F-1D18A9856A870000-0001-7149-769X Georgi A Dimchev author 38C393BE-F248-11E8-B48F-1D18A9856A870000-0001-8370-6161 Victor-Valentin Hodirnau author 3661B498-F248-11E8-B48F-1D18A9856A870000-0003-3904-947X William Wan author Florian KM Schur author 48AD8942-F248-11E8-B48F-1D18A9856A870000-0003-4790-8078 FlSc department EM-Fac department Structure and isoform diversity of the Arp2/3 complex project Protein structure and function in filopodia across scales project The actin-related protein (Arp)2/3 complex nucleates branched actin filament networks pivotal for cell migration, endocytosis and pathogen infection. Its activation is tightly regulated and involves complex structural rearrangements and actin filament binding, which are yet to be understood. Here, we report a 9.0 Å resolution structure of the actin filament Arp2/3 complex branch junction in cells using cryo-electron tomography and subtomogram averaging. This allows us to generate an accurate model of the active Arp2/3 complex in the branch junction and its interaction with actin filaments. Notably, our model reveals a previously undescribed set of interactions of the Arp2/3 complex with the mother filament, significantly different to the previous branch junction model. Our structure also indicates a central role for the ArpC3 subunit in stabilizing the active conformation. https://research-explorer.ista.ac.at/download/8971/8975/2020_NatureComm_Faessler.pdf application/pdfno Springer Nature2020 eng General BiochemistryGenetics and Molecular BiologyGeneral Physics and AstronomyGeneral Chemistry 2041-1723 00060307800000310.1038/s41467-020-20286-x 11 https://ist.ac.at/en/news/cutting-edge-technology-reveals-structures-within-cells/ Fäßler F, Dimchev GA, Hodirnau V-V, Wan W, Schur FK. 2020. Cryo-electron tomography structure of Arp2/3 complex in cells reveals new insights into the branch junction. Nature Communications. 11, 6437. F. Fäßler, G.A. Dimchev, V.-V. Hodirnau, W. Wan, F.K. Schur, Nature Communications 11 (2020). Fäßler, F., Dimchev, G. A., Hodirnau, V.-V., Wan, W., &#38; Schur, F. K. (2020). Cryo-electron tomography structure of Arp2/3 complex in cells reveals new insights into the branch junction. <i>Nature Communications</i>. Springer Nature. <a href="https://doi.org/10.1038/s41467-020-20286-x">https://doi.org/10.1038/s41467-020-20286-x</a> Fäßler F, Dimchev GA, Hodirnau V-V, Wan W, Schur FK. Cryo-electron tomography structure of Arp2/3 complex in cells reveals new insights into the branch junction. <i>Nature Communications</i>. 2020;11. doi:<a href="https://doi.org/10.1038/s41467-020-20286-x">10.1038/s41467-020-20286-x</a> Fäßler, Florian, Georgi A Dimchev, Victor-Valentin Hodirnau, William Wan, and Florian KM Schur. “Cryo-Electron Tomography Structure of Arp2/3 Complex in Cells Reveals New Insights into the Branch Junction.” <i>Nature Communications</i>. Springer Nature, 2020. <a href="https://doi.org/10.1038/s41467-020-20286-x">https://doi.org/10.1038/s41467-020-20286-x</a>. Fäßler, Florian, et al. “Cryo-Electron Tomography Structure of Arp2/3 Complex in Cells Reveals New Insights into the Branch Junction.” <i>Nature Communications</i>, vol. 11, 6437, Springer Nature, 2020, doi:<a href="https://doi.org/10.1038/s41467-020-20286-x">10.1038/s41467-020-20286-x</a>. F. Fäßler, G. A. Dimchev, V.-V. Hodirnau, W. Wan, and F. K. Schur, “Cryo-electron tomography structure of Arp2/3 complex in cells reveals new insights into the branch junction,” <i>Nature Communications</i>, vol. 11. Springer Nature, 2020. 89712020-12-23T08:25:45Z2025-04-15T07:52:12Z