Structural and functional analysis of LIM domain-dependent recruitment of paxillin to αvβ3 integrin-positive focal adhesions

Abstract The LIM domain-dependent localization of the adapter protein paxillin to β3 integrin-positive focal adhesions (FAs) is not mechanistically understood. Here, by combining molecular biology, photoactivation and FA-isolation experiments, we demonstrate specific contributions each domain reveal multiple interactions in adhesion-complexes. Mutation integrin at a putative binding site (β3 VE/YA ) leads rapidly inward-sliding FAs, correlating with actin retrograde flow enhanced dissociation kinetics. Induced mechanical coupling arrests FA-sliding, thereby disclosing an essential structural function for maturation integrin/talin clusters. Moreover, bimolecular fluorescence complementation unveils spatial orientation LIM-array, juxtaposing positive LIM4 plasma membrane integrin-tail, while vitro assays point LIM1 and/or LIM2 interaction talin-head domain. These data provide insights into organization integrin-FAs.