PT  - JOURNAL ARTICLE
AU  - Lea Feld
AU  - Lior Kellerman
AU  - Abhishek Mukherjee
AU  - Ariel Livne
AU  - Eran Bouchbinder
AU  - Haguy Wolfenson
TI  - Cellular contractile forces emerge from time and F-actin dependent non-mechanosensitive displacements
AID  - 10.1101/733303
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 733303
4099  - http://biorxiv.org/content/early/2019/08/13/733303.short
4100  - http://biorxiv.org/content/early/2019/08/13/733303.full
AB  - The ability to actively apply contractile forces to their environment and to sense its mechanical properties are fundamental features of cells. The widespread view is that contractile forces are mechanosensitive, i.e. that cells regulate these forces through sensing the rigidity of the environment. Here we use theory and extensive experiments to study the time evolution of cellular contractile forces. We show that they are generated by an intrinsic, time-dependent contractile displacement that is independent of the environment’s rigidity. Consequently, whereas contractile forces indeed depend on the environment’s rigidity and in fact linearly scale with it, they do so through a purely mechanistic linear force-rigidity relation, i.e. in a non-mechanosensitive manner. Furthermore, we show that the force-generating contractile displacement is directly related to the evolution of the actomyosin network, most notably to the time-dependent concentration of F-actin. The emerging picture of force generation and mechanosensitivity unifies various existing observations on cellular contractility.