1202.5114 (Daniel Gordon et al.)

Hierarchical self-organization of cytoskeletal active networks    [PDF]

Daniel Gordon, Anne Bernheim-Groswasser, Chen Keasar, Oded Farago

The structural reorganization of the actin cytoskeleton is facilitated
through the action of motor proteins that crosslink the actin filaments and
transport them relative to each other. Here, we present a combined
experimental-computational study that probes the dynamic evolution of mixtures
of actin filaments and clusters of myosin motors. While on small spatial and
temporal scales the system behaves in a very noisy manner, on larger scales it
evolves into several well distinct patterns such as bundles, asters, and
networks. These patterns are characterized by junctions with high connectivity,
whose formation is possible due to the organization of the motors in
"oligoclusters" (intermediate-size aggregates). The simulations reveal that the
self-organization process proceeds through a series of hierarchical steps,
starting from local microscopic moves and ranging up to the macroscopic large
scales where the steady-state structures are formed. Our results shed light
into the mechanisms involved in processes like cytokinesis and cellular
contractility, where myosin motors organized in clusters operate cooperatively
to induce structural organization of cytoskeletal networks.

View original: http://arxiv.org/abs/1202.5114