The talin–integrin interface under mechanical stress

The major mechanical function of talin is to couple the β-integrin cytoplasmic tails to actin filaments. A variety of β-integrin tails contain conserved binding motifs for talin, and recent research shows that β-integrins differ both in affinity to talin and preferences for other cytoplasmic adaptor proteins. While talin predominantly links β3 integrins to actin filaments within the peripheral cell adhesion sites, talin can become replaced by other integrin adaptor proteins through their overlapping binding sites on integrin tails. Although the NPxY motif in the β-integrin tail is important for talin recognition, our simulations suggest considerably smaller contribution of the NPxY motif in the force resistance of the talin–integrin complex than for the residues upstream of the NPxY. It might thus be possible for the NPxY motif to detach from talin and interact with other integrin binding proteins while the β-integrin still remains bound to talin. The epithelial integrin β6 reportedly activates latent TGFβ1, and we propose that its function may involve direct interaction with talin.