---
_id: '14782'
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.
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.
article_processing_charge: Yes (in subscription journal)
article_type: original
author:
- first_name: Lucia
  full_name: Baldauf, Lucia
  last_name: Baldauf
- first_name: Felix F
  full_name: Frey, Felix F
  id: a0270b37-8f1a-11ec-95c7-8e710c59a4f3
  last_name: Frey
- first_name: Marcos
  full_name: Arribas Perez, Marcos
  last_name: Arribas Perez
- first_name: Timon
  full_name: Idema, Timon
  last_name: Idema
- first_name: Gijsje H.
  full_name: Koenderink, Gijsje H.
  last_name: Koenderink
citation:
  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>
  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>
  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.
  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.
  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>.
  short: L. Baldauf, F.F. Frey, M. Arribas Perez, T. Idema, G.H. Koenderink, Biophysical
    Journal 122 (2023) 2311–2324.
date_created: 2024-01-10T09:45:48Z
date_published: 2023-06-06T00:00:00Z
date_updated: 2024-01-16T09:20:03Z
day: '06'
ddc:
- '570'
department:
- _id: AnSa
doi: 10.1016/j.bpj.2023.02.018
external_id:
  isi:
  - '001016792600001'
  pmid:
  - '36806830'
file:
- access_level: open_access
  checksum: 70566e54cd95ea6df340909ad44c5cd5
  content_type: application/pdf
  creator: dernst
  date_created: 2024-01-16T09:09:29Z
  date_updated: 2024-01-16T09:09:29Z
  file_id: '14807'
  file_name: 2023_BiophysicalJournal_Baldauf.pdf
  file_size: 3285810
  relation: main_file
  success: 1
file_date_updated: 2024-01-16T09:09:29Z
has_accepted_license: '1'
intvolume: '       122'
isi: 1
issue: '11'
keyword:
- Biophysics
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
page: 2311-2324
pmid: 1
publication: Biophysical Journal
publication_identifier:
  issn:
  - 0006-3495
publication_status: published
publisher: Elsevier
quality_controlled: '1'
related_material:
  link:
  - relation: software
    url: https://github.com/BioSoftMatterGroup/actin-curvature-sensing
status: public
title: Branched actin cortices reconstituted in vesicles sense membrane curvature
tmp:
  image: /images/cc_by_nc_nd.png
  legal_code_url: https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode
  name: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
    (CC BY-NC-ND 4.0)
  short: CC BY-NC-ND (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 122
year: '2023'
...