Charge-dependent interactions of monomeric and filamentous actin with lipid bilayers

Carsten F E Schroer, Lucia Baldauf, Lennard van Buren, Tsjerk A Wassenaar, Manuel N Melo, Gijsje H Koenderink, Siewert J Marrink*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

28 Citations (Scopus)
127 Downloads (Pure)


The cytoskeletal protein actin polymerizes into filaments that are essential for the mechanical stability of mammalian cells. In vitro experiments showed that direct interactions between actin filaments and lipid bilayers are possible and that the net charge of the bilayer as well as the presence of divalent ions in the buffer play an important role. In vivo, colocalization of actin filaments and divalent ions are suppressed, and cells rely on linker proteins to connect the plasma membrane to the actin network. Little is known, however, about why this is the case and what microscopic interactions are important. A deeper understanding is highly beneficial, first, to obtain understanding in the biological design of cells and, second, as a possible basis for the building of artificial cortices for the stabilization of synthetic cells. Here, we report the results of coarse-grained molecular dynamics simulations of monomeric and filamentous actin in the vicinity of differently charged lipid bilayers. We observe that charges on the lipid head groups strongly determine the ability of actin to adsorb to the bilayer. The inclusion of divalent ions leads to a reversal of the binding affinity. Our in silico results are validated experimentally by reconstitution assays with actin on lipid bilayer membranes and provide a molecular-level understanding of the actin-membrane interaction.

Original languageEnglish
Article numberpnas.1914884117
Pages (from-to)5861-5872
Number of pages12
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number11
Early online date2020
Publication statusPublished - 17-Mar-2020


  • actin cytoskeleton
  • protein-lipid interactions
  • coarse-grained molecular dynamics
  • biological soft matter
  • artificial cell cortex

Cite this