LIM Domain Proteins link molecular and global tension by recognizing strained actin in adhesions

Mechanotransduction is fundamental to cell signaling and depends on force-sensitive adhesion proteins. How these proteins differentiate and integrate their responses to tension remains an open question. We show mechanosensitive LIM domain proteins like zyxin detect global adhesion tension by recognizing strained actin within these structures. In sharp contrast, vinculin localization and intramolecular tension remain unchanged, despite vinculin's well-documented role in mechanotransduction. This reveals a stark disconnect between molecular tension and global tension in adhesions. We further show tension-dependent localization is specific to LIM domain proteins that recognize strained actin and extends to LIM proteins at cell-cell junctions, suggesting a common mechanotransduction mechanism. Finally, we show zyxin's tension-dependent adhesion localization stabilizes actin and recruits VASP to promote stress fiber polymerization, identical to its role in stress fiber repair. Our findings reveal a fundamental role for LIM domain protein force-sensing in adhesions and highlight the non-linear connection between molecular and global tension.