Growing networks of actin fibers are able to organize into compact, stiff two-dimensional structures inside lamellipodia of crawling cells. We put forward the hypothesis that the growing actin network is a critically self-organized system, in which long-range mechanical stresses arising from the interaction with the plasma membrane provide the selective pressure leading to organization. We show that a simple model based only on this principle reproduces the stochastic nature of lamellipodia protrusion (growth periods alternating with fast retractions) and several of the features observed in experiments: a growth velocity initially insensitive to the external force; the capability of the network to organize its orientation; a load-history-dependent growth velocity. Our model predicts that the spectrum of the time series of the height of a growing lamellipodium decays with the inverse of the frequency. This behavior is a well-known signature of self-organized criticality and is confirmed by unique optical tweezer measurements performed in vivo on neuronal growth cones.
|Titolo:||Cytoskeletal actin networks in motile cells are critically self-organized systems synchronized by mechanical interactions|
|Autori:||Cardamone, L; Laio, Alessandro; Torre, Vincent; Shahapure, R; De Simone, Antonio|
|Data di pubblicazione:||2011|
|Digital Object Identifier (DOI):||10.1073/pnas.1100549108|
|Appare nelle tipologie:||1.1 Journal article|