Biochemical analysis of the human ENA/VASP-family proteins, MENA, VASP and EVL, in homologous recombination

J Biochem. 2011 Jun;149(6):721-9. doi: 10.1093/jb/mvr029. Epub 2011 Mar 11.

Abstract

MENA, VASP and EVL are members of the ENA/VASP family of proteins and are involved in cytoplasmic actin remodeling. Previously, we found that EVL directly interacts with RAD51, an essential protein in the homologous recombinational repair of double-strand breaks (DSBs) and stimulates the RAD51-mediated recombination reactions in vitro. The EVL-knockdown MCF7 cells exhibited a clear reduction in RAD51-foci formation, suggesting that EVL may function in the DSB repair pathway through RAD51-mediated homologous recombination. However, the DSB repair defects were less significant in the EVL-knockdown cells, implying that two EVL paralogues, MENA and VASP, may complement the EVL function in human cells. Therefore, in the present study, we purified human MENA, VASP and EVL as recombinant proteins, and compared their biochemical activities in vitro. We found that all three proteins commonly exhibited the RAD51 binding, DNA binding and DNA-annealing activities. Stimulation of the RAD51-mediated homologous pairing was also observed with all three proteins. In addition, surface plasmon resonance analyses revealed that MENA, VASP and EVL mutually interacted. These results support the ideas that the ENA/VASP-family proteins are functionally redundant in homologous recombination, and that all three may be involved in the DSB repair pathway in humans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Adhesion Molecules / genetics
  • Cell Adhesion Molecules / metabolism*
  • DNA / chemistry
  • DNA / metabolism
  • Homologous Recombination*
  • Humans
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism*
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Rad51 Recombinase / chemistry
  • Rad51 Recombinase / metabolism
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Surface Plasmon Resonance

Substances

  • Cell Adhesion Molecules
  • EVL protein, human
  • Enah protein, human
  • Microfilament Proteins
  • Phosphoproteins
  • Recombinant Proteins
  • vasodilator-stimulated phosphoprotein
  • DNA
  • Rad51 Recombinase