Interaction of human AP endonuclease 1 with flap endonuclease 1 and proliferating cell nuclear antigen involved in long-patch base excision repair

Biochemistry. 2001 Oct 23;40(42):12639-44. doi: 10.1021/bi011117i.

Abstract

To understand the mechanism involved in the coordination of the sequential repair reactions that lead to long-patch BER, we have investigated interactions between proteins involved in this pathway. We find that human AP endonuclease 1 (APE1) physically interacts with flap endonuclease 1 (FEN1) and with proliferating cell nuclear antigen. An oligonucleotide substrate containing a reduced abasic site, which was pre-incised with APE1, was employed to reconstitute the excision step of long-patch BER with purified human DNA polymerase beta and FEN1. We demonstrate that addition of APE1 to the excision reaction mixture slightly (1.5-2-fold) stimulates the removal of the displaced flap by FEN1. These results suggest the possibility that long-patch BER is coordinated and directed by protein-protein interactions.

MeSH terms

  • Carbon-Oxygen Lyases / immunology
  • Carbon-Oxygen Lyases / isolation & purification
  • Carbon-Oxygen Lyases / metabolism*
  • Cells, Cultured
  • DNA Polymerase beta / metabolism
  • DNA Repair*
  • DNA Replication
  • DNA-(Apurinic or Apyrimidinic Site) Lyase
  • Deoxyribonuclease IV (Phage T4-Induced)
  • Endodeoxyribonucleases / immunology
  • Endodeoxyribonucleases / metabolism*
  • Flap Endonucleases
  • Humans
  • Precipitin Tests
  • Proliferating Cell Nuclear Antigen / metabolism*

Substances

  • Proliferating Cell Nuclear Antigen
  • DNA Polymerase beta
  • Endodeoxyribonucleases
  • Flap Endonucleases
  • FEN1 protein, human
  • Deoxyribonuclease IV (Phage T4-Induced)
  • Carbon-Oxygen Lyases
  • APEX1 protein, human
  • DNA-(Apurinic or Apyrimidinic Site) Lyase