RT Journal Article
SR Electronic
T1 Elasticity of dense actin networks produces nanonewton protrusive forces
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.04.13.439622
DO 10.1101/2021.04.13.439622
A1 Marion Jasnin
A1 Jordan Hervy
A1 Stéphanie Balor
A1 Anais Bouissou
A1 Amsha Proag
A1 Raphaël Voituriez
A1 Isabelle Maridonneau-Parini
A1 Wolfgang Baumeister
A1 Serge Dmitrieff
A1 Renaud Poincloux
YR 2021
UL http://biorxiv.org/content/early/2021/04/14/2021.04.13.439622.abstract
AB Actin filaments assemble into force-generating systems involved in diverse cellular functions, including cell motility, adhesion, contractility and division. It remains unclear how networks of actin filaments, which individually generate piconewton forces, can produce forces reaching tens of nanonewtons. Here we use in situ cryo-electron tomography to unveil how the nanoscale architecture of macrophage podosomes enables basal membrane protrusion. We show that the sum of the actin polymerization forces at the membrane is not sufficient to explain podosome protrusive forces. Quantitative analysis of podosome organization demonstrates that the core is composed of a dense network of bent actin filaments storing elastic energy. Theoretical modelling of the network as a spring-loaded elastic material reveals that it exerts forces of up to tens of nanonewtons, similar to those evaluated experimentally. Thus, taking into account not only the interface with the membrane but also the bulk of the network, is crucial to understand force generation by actin machineries. Our integrative approach sheds light on the elastic behavior of dense actin networks and opens new avenues to understand force production inside cells.Competing Interest StatementThe authors have declared no competing interest.