2024/08/31 by Mehdi Bouzid, Cesar Valencia Gallardo, Bouzid, Mehdi +12 · 2 citations
Biochemistry, Genetics and Molecular Biology · Medicine · Physics and Astronomy · #Actin #Biological Physics (physics.bio-ph) #Biology #Cardiomyopathy and Myosin Studies #Cell biology #Cellular Mechanics and Interactions #Composite material #Computer science #Elasticity (physics) #FOS: Biological sciences #FOS: Physical sciences #Force Microscopy Techniques and Applications #Materials science #Mechanics #Physics #Soft Condensed Matter (cond-mat.soft) #Subcellular Processes (q-bio.SC) #Transient (computer programming)
paper · pdf · doi:10.48550/arxiv.2409.00549
published in arXiv (Cornell University) (Cornell University)
openalex publication_date 2024/08/31 · openalex created_date 2024/10/05 · openalex updated_date 2026/07/28
Branched actin networks exert pushing forces in eukaryotic cells, and adapt their stiffness to their environment. The physical basis for their mechanics and adaptability is however not understood. Indeed, here we show that their high density and low connectivity place them outside the scope of standard elastic network models for actin. We combine high-precision mechanical experiments, molecular dynamics simulations and a mean-field elastic theory to show that they are instead dominated by the proliferation of interfilament contacts under compression. This places branched actin in the same category as undercoordinated, fibrous materials such as sheep's wool. When the network is grown under force, filaments entangle as if knitted together and trap contacts in their structure. Trapped contacts play a similar role as crosslinkers in rigidifying the network, and are thus key to its active adaptive mechanics.