Spatial coordination of kindlin-2 with talin head domain in interaction with integrin β cytoplasmic tails

J Biol Chem. 2012 Jul 13;287(29):24585-94. doi: 10.1074/jbc.M111.336743. Epub 2012 May 30.

Abstract

Both talin head domain and kindlin-2 interact with integrin β cytoplasmic tails, and they function in concert to induce integrin activation. Binding of talin head domain to β cytoplasmic tails has been characterized extensively, but information on the interaction of kindin-2 with this integrin segment is limited. In this study, we systematically examine the interactions of kindlin-2 with integrin β tails. Kindlin-2 interacted well with β(1) and β(3) tails but poorly with the β(2) cytoplasmic tail. This binding selectivity was determined by the non-conserved residues, primarily the three amino acids at the extreme C terminus of the β(3) tail, and the sequence in β(2) was non-permissive. The region at the C termini of integrin β(1) and β(3) tails recognized by kindlin-2 was a binding core of 12 amino acids. Kindlin-2 and talin head do not interact with one another but can bind simultaneously to the integrin β(3) tail without enhancing or inhibiting the interaction of the other binding partner. Kindlin-2 itself failed to directly unclasp integrin α/β tail complex, indicating that kindlin-2 must cooperate with talin to support the integrin activation mechanism.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • CHO Cells
  • Calorimetry
  • Chromatography, High Pressure Liquid
  • Cricetinae
  • Cytoplasm / metabolism*
  • Integrin beta Chains / chemistry*
  • Integrin beta Chains / metabolism*
  • Magnetic Resonance Spectroscopy
  • Membrane Proteins / chemistry*
  • Membrane Proteins / metabolism*
  • Neoplasm Proteins / chemistry*
  • Neoplasm Proteins / metabolism*
  • Protein Structure, Tertiary
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Surface Plasmon Resonance
  • Talin / chemistry*
  • Talin / metabolism*

Substances

  • FERMT3 protein, human
  • Integrin beta Chains
  • Membrane Proteins
  • Neoplasm Proteins
  • Talin