Roles of Talin2 in Traction Force Generation, Tumor Metastasis and Cardiovascular Integrity.

There are two vertebrate talin genes, TLN1 and TLN2, which encode talin1 and talin2. Talin1 governs integrin activation, thus regulating focal adhesion (FA) assembly, cell migration and invasion, but the biological function of talin2 remains to be elucidated and not too long ago talin2 was presumed to function redundantly with talin1. Recent studies have shown distinct differences between talin2 and talin1. The promoter of TLN2 is different from that of TLN1 in their size and binding to different transcription factors. Talin2 has a higher affinity to β -integrins than talin1. Talin2 regulates traction force generation, focal adhesion dynamics and invadopodium formation, thus controlling tumor cell migration, invasion and metastasis. Also, talin2 is enriched in the myotendinous junction (MTJ) in striated muscle, costameres and intercalated disks (ICDs) of cardiac myofibrils, and atherosclerotic plaques of blood vessels, thus regulating cardiovascular integrity. In this review, we discuss the differences between talin1 and talin2, in genome, protein expression pattern, affinity with integrins, traction force generation, and provide a glance at the roles of talin2 in cancer cell invasion and cardiovascular function.