[{"abstract":[{"lang":"eng","text":"The actin cortex is a complex cytoskeletal machinery that drives and responds to changes in cell shape. It must generate or adapt to plasma membrane curvature to facilitate diverse functions such as cell division, migration, and phagocytosis. Due to the complex molecular makeup of the actin cortex, it remains unclear whether actin networks are inherently able to sense and generate membrane curvature, or whether they rely on their diverse binding partners to accomplish this. Here, we show that curvature sensing is an inherent capability of branched actin networks nucleated by Arp2/3 and VCA. We develop a robust method to encapsulate actin inside giant unilamellar vesicles (GUVs) and assemble an actin cortex at the inner surface of the GUV membrane. We show that actin forms a uniform and thin cortical layer when present at high concentration and distinct patches associated with negative membrane curvature at low concentration. Serendipitously, we find that the GUV production method also produces dumbbell-shaped GUVs, which we explain using mathematical modeling in terms of membrane hemifusion of nested GUVs. We find that branched actin networks preferentially assemble at the neck of the dumbbells, which possess a micrometer-range convex curvature comparable with the curvature of the actin patches found in spherical GUVs. Minimal branched actin networks can thus sense membrane curvature, which may help mammalian cells to robustly recruit actin to curved membranes to facilitate diverse cellular functions such as cytokinesis and migration."}],"day":"06","tmp":{"image":"/images/cc_by_nc_nd.png","short":"CC BY-NC-ND (4.0)","name":"Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)","legal_code_url":"https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode"},"oa_version":"Published Version","page":"2311-2324","publication_status":"published","license":"https://creativecommons.org/licenses/by-nc-nd/4.0/","status":"public","date_updated":"2024-01-16T09:20:03Z","file":[{"content_type":"application/pdf","relation":"main_file","access_level":"open_access","creator":"dernst","success":1,"date_updated":"2024-01-16T09:09:29Z","date_created":"2024-01-16T09:09:29Z","checksum":"70566e54cd95ea6df340909ad44c5cd5","file_id":"14807","file_size":3285810,"file_name":"2023_BiophysicalJournal_Baldauf.pdf"}],"title":"Branched actin cortices reconstituted in vesicles sense membrane curvature","external_id":{"isi":["001016792600001"],"pmid":["36806830"]},"related_material":{"link":[{"relation":"software","url":"https://github.com/BioSoftMatterGroup/actin-curvature-sensing"}]},"publication":"Biophysical Journal","has_accepted_license":"1","issue":"11","citation":{"chicago":"Baldauf, Lucia, Felix F Frey, Marcos Arribas Perez, Timon Idema, and Gijsje H. Koenderink. “Branched Actin Cortices Reconstituted in Vesicles Sense Membrane Curvature.” <i>Biophysical Journal</i>. Elsevier, 2023. <a href=\"https://doi.org/10.1016/j.bpj.2023.02.018\">https://doi.org/10.1016/j.bpj.2023.02.018</a>.","ieee":"L. Baldauf, F. F. Frey, M. Arribas Perez, T. Idema, and G. H. Koenderink, “Branched actin cortices reconstituted in vesicles sense membrane curvature,” <i>Biophysical Journal</i>, vol. 122, no. 11. Elsevier, pp. 2311–2324, 2023.","mla":"Baldauf, Lucia, et al. “Branched Actin Cortices Reconstituted in Vesicles Sense Membrane Curvature.” <i>Biophysical Journal</i>, vol. 122, no. 11, Elsevier, 2023, pp. 2311–24, doi:<a href=\"https://doi.org/10.1016/j.bpj.2023.02.018\">10.1016/j.bpj.2023.02.018</a>.","apa":"Baldauf, L., Frey, F. F., Arribas Perez, M., Idema, T., &#38; Koenderink, G. H. (2023). Branched actin cortices reconstituted in vesicles sense membrane curvature. <i>Biophysical Journal</i>. Elsevier. <a href=\"https://doi.org/10.1016/j.bpj.2023.02.018\">https://doi.org/10.1016/j.bpj.2023.02.018</a>","ista":"Baldauf L, Frey FF, Arribas Perez M, Idema T, Koenderink GH. 2023. Branched actin cortices reconstituted in vesicles sense membrane curvature. Biophysical Journal. 122(11), 2311–2324.","short":"L. Baldauf, F.F. Frey, M. Arribas Perez, T. Idema, G.H. Koenderink, Biophysical Journal 122 (2023) 2311–2324.","ama":"Baldauf L, Frey FF, Arribas Perez M, Idema T, Koenderink GH. Branched actin cortices reconstituted in vesicles sense membrane curvature. <i>Biophysical Journal</i>. 2023;122(11):2311-2324. doi:<a href=\"https://doi.org/10.1016/j.bpj.2023.02.018\">10.1016/j.bpj.2023.02.018</a>"},"date_published":"2023-06-06T00:00:00Z","_id":"14782","oa":1,"author":[{"first_name":"Lucia","full_name":"Baldauf, Lucia","last_name":"Baldauf"},{"first_name":"Felix F","full_name":"Frey, Felix F","last_name":"Frey","id":"a0270b37-8f1a-11ec-95c7-8e710c59a4f3"},{"first_name":"Marcos","full_name":"Arribas Perez, Marcos","last_name":"Arribas Perez"},{"first_name":"Timon","full_name":"Idema, Timon","last_name":"Idema"},{"last_name":"Koenderink","full_name":"Koenderink, Gijsje H.","first_name":"Gijsje H."}],"type":"journal_article","year":"2023","publisher":"Elsevier","doi":"10.1016/j.bpj.2023.02.018","language":[{"iso":"eng"}],"volume":122,"article_type":"original","isi":1,"publication_identifier":{"issn":["0006-3495"]},"quality_controlled":"1","month":"06","intvolume":"       122","keyword":["Biophysics"],"file_date_updated":"2024-01-16T09:09:29Z","article_processing_charge":"Yes (in subscription journal)","ddc":["570"],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","acknowledgement":"We thank Jeffrey den Haan for protein purification, Kristina Ganzinger (AMOLF) for providing the 10xHis VCA construct, David Kovar (University of Chicago) for the CP constructs, and Michael Way (Crick Institute) for providing purified human Arp2/3 proteins. We are grateful to Iris Lambert for early actin encapsulation experiments that formed the basis for establishing the eDICE method, to Federico Fanalista for acquiring images of dumbbell-shaped GUVs in samples produced by cDICE, and to Tom Aarts for images of dumbbell-shaped GUVs produced by gel-assisted swelling. Lennard van Buren is thanked for his help with image analysis to quantify actin concentrations in GUVs. We thank Kristina Ganzinger (AMOLF) for hosting us to perform pyrene assays in her lab, and Balász Antalicz (AMOLF) for technical assistance with the spectrophotometer. The authors also thank Matthieu Piel and Daniel Fletcher for insightful and inspiring discussions. We acknowledge financial support from The Netherlands Organization of Scientific Research (NWO/OCW) Gravitation program Building a Synthetic Cell (BaSyC) (024.003.019). F.F. gratefully acknowledges funding from the Kavli Synergy program of the Kavli Institute of Nanoscience Delft.","department":[{"_id":"AnSa"}],"pmid":1,"date_created":"2024-01-10T09:45:48Z"},{"isi":1,"volume":222,"article_type":"original","month":"02","quality_controlled":"1","publication_identifier":{"eissn":["1540-8140"],"issn":["0021-9525"]},"ddc":["570"],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_processing_charge":"No","file_date_updated":"2024-01-16T10:15:09Z","keyword":["Cell Biology"],"intvolume":"       222","date_created":"2024-01-10T10:45:55Z","article_number":"e202206038","pmid":1,"department":[{"_id":"AnSa"}],"acknowledgement":"We thank the entire Ries and Kaksonen labs for fruitful discussions and support. This work was supported by the European Research Council (ERC CoG-724489 to J. Ries), the National Institutes of Health Common Fund 4D Nucleome Program (Grant U01 to J. Ries), the Human Frontier Science Program (RGY0065/2017 to J. Ries), the EMBL Interdisciplinary Postdoc Programme (EIPOD) under Marie Curie Actions COFUND (Grant 229597 to O. Avinoam), the European Molecular Biology Laboratory (M. Mund, A. Tschanz, Y.-L. Wu and J. Ries), and the Swiss National Science Foundation (grant 310030B_182825 and NCCR Chemical Biology to M. Kaksonen). O. Avinoam is an incumbent of the Miriam Berman Presidential Development Chair.","date_published":"2023-02-03T00:00:00Z","author":[{"first_name":"Markus","full_name":"Mund, Markus","last_name":"Mund"},{"last_name":"Tschanz","first_name":"Aline","full_name":"Tschanz, Aline"},{"last_name":"Wu","full_name":"Wu, Yu-Le","first_name":"Yu-Le"},{"full_name":"Frey, Felix F","first_name":"Felix F","id":"a0270b37-8f1a-11ec-95c7-8e710c59a4f3","last_name":"Frey","orcid":"0000-0001-8501-6017"},{"last_name":"Mehl","first_name":"Johanna L.","full_name":"Mehl, Johanna L."},{"first_name":"Marko","full_name":"Kaksonen, Marko","last_name":"Kaksonen"},{"last_name":"Avinoam","first_name":"Ori","full_name":"Avinoam, Ori"},{"last_name":"Schwarz","first_name":"Ulrich S.","full_name":"Schwarz, Ulrich S."},{"full_name":"Ries, Jonas","first_name":"Jonas","last_name":"Ries"}],"oa":1,"_id":"14788","type":"journal_article","language":[{"iso":"eng"}],"doi":"10.1083/jcb.202206038","publisher":"Rockefeller University Press","year":"2023","publication":"Journal of Cell Biology","external_id":{"isi":["000978065000001"],"pmid":["36734980"]},"file":[{"creator":"dernst","access_level":"open_access","relation":"main_file","content_type":"application/pdf","file_name":"2023_JCB_Mund.pdf","file_size":5678069,"date_created":"2024-01-16T10:15:09Z","file_id":"14811","checksum":"505d5cac36c14b073b68c7fed1a92bd3","date_updated":"2024-01-16T10:15:09Z","success":1}],"title":"Clathrin coats partially preassemble and subsequently bend during endocytosis","issue":"3","has_accepted_license":"1","citation":{"chicago":"Mund, Markus, Aline Tschanz, Yu-Le Wu, Felix F Frey, Johanna L. Mehl, Marko Kaksonen, Ori Avinoam, Ulrich S. Schwarz, and Jonas Ries. “Clathrin Coats Partially Preassemble and Subsequently Bend during Endocytosis.” <i>Journal of Cell Biology</i>. Rockefeller University Press, 2023. <a href=\"https://doi.org/10.1083/jcb.202206038\">https://doi.org/10.1083/jcb.202206038</a>.","ieee":"M. Mund <i>et al.</i>, “Clathrin coats partially preassemble and subsequently bend during endocytosis,” <i>Journal of Cell Biology</i>, vol. 222, no. 3. Rockefeller University Press, 2023.","apa":"Mund, M., Tschanz, A., Wu, Y.-L., Frey, F. F., Mehl, J. L., Kaksonen, M., … Ries, J. (2023). Clathrin coats partially preassemble and subsequently bend during endocytosis. <i>Journal of Cell Biology</i>. Rockefeller University Press. <a href=\"https://doi.org/10.1083/jcb.202206038\">https://doi.org/10.1083/jcb.202206038</a>","short":"M. Mund, A. Tschanz, Y.-L. Wu, F.F. Frey, J.L. Mehl, M. Kaksonen, O. Avinoam, U.S. Schwarz, J. Ries, Journal of Cell Biology 222 (2023).","ista":"Mund M, Tschanz A, Wu Y-L, Frey FF, Mehl JL, Kaksonen M, Avinoam O, Schwarz US, Ries J. 2023. Clathrin coats partially preassemble and subsequently bend during endocytosis. Journal of Cell Biology. 222(3), e202206038.","mla":"Mund, Markus, et al. “Clathrin Coats Partially Preassemble and Subsequently Bend during Endocytosis.” <i>Journal of Cell Biology</i>, vol. 222, no. 3, e202206038, Rockefeller University Press, 2023, doi:<a href=\"https://doi.org/10.1083/jcb.202206038\">10.1083/jcb.202206038</a>.","ama":"Mund M, Tschanz A, Wu Y-L, et al. Clathrin coats partially preassemble and subsequently bend during endocytosis. <i>Journal of Cell Biology</i>. 2023;222(3). doi:<a href=\"https://doi.org/10.1083/jcb.202206038\">10.1083/jcb.202206038</a>"},"oa_version":"Published Version","publication_status":"published","day":"03","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"abstract":[{"text":"Eukaryotic cells use clathrin-mediated endocytosis to take up a large range of extracellular cargo. During endocytosis, a clathrin coat forms on the plasma membrane, but it remains controversial when and how it is remodeled into a spherical vesicle.\r\nHere, we use 3D superresolution microscopy to determine the precise geometry of the clathrin coat at large numbers of endocytic sites. Through pseudo-temporal sorting, we determine the average trajectory of clathrin remodeling during endocytosis. We find that clathrin coats assemble first on flat membranes to 50% of the coat area before they become rapidly and continuously bent, and this mechanism is confirmed in three cell lines. We introduce the cooperative curvature model, which is based on positive feedback for curvature generation. It accurately describes the measured shapes and dynamics of the clathrin coat and could represent a general mechanism for clathrin coat remodeling on the plasma membrane.","lang":"eng"}],"status":"public","license":"https://creativecommons.org/licenses/by/4.0/","date_updated":"2024-01-16T10:17:05Z"}]