Mechanosensitive Self-Assembly of Myosin II Minifilaments

Abstract

Self-assembly and force generation are two central processes in biological systems that usually are considered in separation. However, the signals that activate non-muscle myosin II molecular motors simultaneously lead to self-assembly into myosin II minifilaments as well as progression of the motor heads through the crossbridge cycle. Here we investigate theoretically the possible effects of coupling these two processes. Our assembly model, which builds upon a consensus architecture of the minifilament, predicts a critical aggregation concentration at which the assembly kinetics slows down dramatically. The combined model predicts that increasing actin filament concentration and force both lead to a decrease in the critical aggregation concentration. We suggest that due to these effects, myosin II minifilaments in a filamentous context might be in a critical state that reacts faster to varying conditions than in solution. We finally compare our model to experiments by simulating fluorescence recovery after photobleaching.

15 pages, 6 figures, 4 supplemental figures

References in corpus (4)

• Minimal coarse-grained models for molecular self-organisation in biology
• Role of dynamic capsomere supply for viral capsid self-assembly
• Sensitivity of small myosin II ensembles from different isoforms to mechanical load and ATP concentration
• Stochastic dynamics and mechanosensitivity of myosin II minifilaments

Cited by in corpus (1)

• Enhancement and Suppression of Active Particle Movement Due to Membrane Deformations