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

Commun Biol. 2021 Mar 29;4(1):380. doi: 10.1038/s42003-021-01886-9.


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 of each LIM domain of paxillin and reveal multiple paxillin interactions in adhesion-complexes. Mutation of β3 integrin at a putative paxillin binding site (β3VE/YA) leads to rapidly inward-sliding FAs, correlating with actin retrograde flow and enhanced paxillin dissociation kinetics. Induced mechanical coupling of paxillin to β3VE/YA integrin arrests the FA-sliding, thereby disclosing an essential structural function of paxillin for the maturation of β3 integrin/talin clusters. Moreover, bimolecular fluorescence complementation unveils the spatial orientation of the paxillin LIM-array, juxtaposing the positive LIM4 to the plasma membrane and the β3 integrin-tail, while in vitro binding assays point to LIM1 and/or LIM2 interaction with talin-head domain. These data provide structural insights into the molecular organization of β3 integrin-FAs.

Publication types

  • Research Support, Non-U.S. Gov't
  • Video-Audio Media

MeSH terms

  • Animals
  • Binding Sites
  • Fibroblasts / metabolism*
  • Fluorescence Recovery After Photobleaching
  • Focal Adhesions / genetics
  • Focal Adhesions / metabolism*
  • Integrin alphaVbeta3 / genetics
  • Integrin alphaVbeta3 / metabolism*
  • Kinetics
  • Mice
  • Microscopy, Confocal
  • Microscopy, Fluorescence
  • NIH 3T3 Cells
  • Paxillin / genetics
  • Paxillin / metabolism*
  • Phenotype
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Protein Stability
  • Structure-Activity Relationship


  • Integrin alphaVbeta3
  • Paxillin
  • Pxn protein, mouse