Fig. 6.

Model of kindlin-mediated integrin activation and clustering. The three states of integrin activation are shown. The binding of talins to the cytoplasmic tails of β-integrins promotes the extension of the extracellular domains of integrins. The activated integrins are further clustered and fully activated via multivalent ECM ligand binding as well as the interaction network mediated by talins and dimeric kindlins. The monomer–dimer transition of kindlins in vivo may require regulators (e.g., membrane environment through either increasing local concentration or altering the conformation of kindlins).