Talin (protein)

Talin is a high-molecular-weight cytoskeletal protein concentrated at regions of cell–substratum contact^[1] and, in lymphocytes, at cell–cell contacts.^[2][3] Discovered in 1983 by Keith Burridge and colleagues,^[1] talin is a ubiquitous cytosolic protein that is found in high concentrations in focal adhesions. It is capable of linking integrins to the actin cytoskeleton either directly or indirectly by interacting with vinculin and α-actinin.^[4]

Also, talin-1 drives extravasation mechanism through engineered human microvasculature in microfluidic systems. Talin-1 is involved in each part of extravasation affecting adhesion, trans-endothelial migration and the invasion stages.^[5]

Integrin receptors are involved in the attachment of adherent cells to the extracellular matrix^[6][7] and of lymphocytes to other cells. In these situations, talin codistributes with concentrations of integrins in the plasma membrane.^[8][9] Furthermore, in vitro binding studies suggest that integrins bind to talin, although with low affinity.^[10] Talin also binds with high affinity to vinculin,^[11] another cytoskeletal protein concentrated at points of cell adhesion.^[12] Finally, talin is a substrate for the calcium-ion activated protease, calpain II,^[13] which is also concentrated at points of cell–substratum contact.^[14]

Talin is a mechanosensitive protein. Its mechanical vulnerability^[15] and cellular position bridging integrin receptors and the actin cytoskeleton make it a fundamental protein in mechanotransduction. Mechanical stretching of talin promotes vinculin binding.^[16]