Kank2 activates talin, reduces force transduction across integrins and induces central adhesion formation

Nat Cell Biol. 2016 Sep;18(9):941-53. doi: 10.1038/ncb3402. Epub 2016 Aug 22.

Abstract

Integrin-based adhesions play critical roles in cell migration. Talin activates integrins and flexibly connects integrins to the actomyosin cytoskeleton, thereby serving as a 'molecular clutch' that transmits forces to the extracellular matrix to drive cell migration. Here we identify the evolutionarily conserved Kank protein family as novel components of focal adhesions (FAs). Kank proteins accumulate at the lateral border of FAs, which we term the FA belt, and in central sliding adhesions, where they directly bind the talin rod domain through the Kank amino-terminal (KN) motif and induce talin and integrin activation. In addition, Kank proteins diminish the talin-actomyosin linkage, which curbs force transmission across integrins, leading to reduced integrin-ligand bond strength, slippage between integrin and ligand, central adhesion formation and sliding, and reduced cell migration speed. Our data identify Kank proteins as talin activators that decrease the grip between the integrin-talin complex and actomyosin to regulate cell migration velocity.

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Carrier Proteins / metabolism*
  • Cell Adhesion
  • Cell Membrane / metabolism
  • Cell Movement
  • Cells, Cultured
  • Cytoskeletal Proteins
  • Cytoskeleton / metabolism
  • Extracellular Matrix / metabolism
  • Focal Adhesions / metabolism*
  • Integrins / metabolism*
  • Mice
  • Talin / metabolism*
  • Vinculin / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Cytoskeletal Proteins
  • Integrins
  • Kank1 protein, mouse
  • Talin
  • Vinculin