Talin is one of the major cytoskeletal proteins involved in integrin activation and linking the resulting focal adhesion (FA) with cytoskeleton. Talin comprises an N-ter head region and a flexible rod domain. The head region has the FERM domain (subdivided into F1, F2 and F3 subdomains), which has the binding sites for beta integrin cytoplasmic regions and actin binding sites close to the C-terminal rod domain.
Talin exists in closed inactive conformation, where the head region interacts with the rod domain masking the integrin binding sites. At the plasma membrane the RIAM bound to active Rap1 recruits talin to form the integrin activation complex. This interaction exposes the integrin-binding site in talin F3 domain leading to integrin activation.