DEPARTAMENTO DE CIÊNCIAS DA VIDA ... - Estudo Geral

14
Figure 3 - The Rigidity Sensing Cycle. In this rigidity sensing cycle scheme it is shown the correlation
between mechanosensory events as integrin/ECM catch bond formation, stretching of talin (that
recruits vinculin and therefore reinforces the adhesion) and stretching of FAK, leading to the
disassembly and recycling of the adhesion, by the activation of its kinase domain. Adapted from; Moore
et al., 2010
This transient and multiple steps active process of rigidity sensing is sensitive to
the matrix rigidity (Figure 3) and so the cell retraction speed (loading rate) felt on the
integrin-ECM catch bond is determined by the substrate rigidity. Just as catch bonds
have a force providing maximum lifetime in a scenario of constant force application,
they will have a corresponding optimal loading rate in scenarios where force is loaded
progressively. But the loading rate, at the optimal rigidity, will maximize bond lifetime,
triggering subsequent mechanotransduction events when a force is applied. Coupling
between rearward flowing actin and the substrate is the key for rigidity sensing
(Moore et al., 2010).