Talin as a mechanosensitive signaling hub

Cell adhesion to the extracellular matrix (ECM), mediated by transmembrane
receptors of the integrin family, is exquisitely sensitive to biochemical,
structural, and mechanical features of the ECM. Talin is a cytoplasmic protein
consisting of a globular head domain and a series of α-helical bundles that form
its long rod domain. Talin binds to the cytoplasmic domain of integrin
β-subunits, activates integrins, couples them to the actin cytoskeleton, and
regulates integrin signaling. Recent evidence suggests switch-like behavior of
the helix bundles that make up the talin rod domains, where individual domains
open at different tension levels, exerting positive or negative effects on
different protein interactions. These results lead us to propose that talin
functions as a mechanosensitive signaling hub that integrates multiple
extracellular and intracellular inputs to define a major axis of adhesion
signaling.