The human Tim-Tipin complex interacts directly with DNA polymerase epsilon and stimulates its synthetic activity

J Biol Chem. 2013 May 3;288(18):12742-52. doi: 10.1074/jbc.M112.398073. Epub 2013 Mar 19.


The Tim-Tipin complex plays an important role in the S phase checkpoint and replication fork stability in metazoans, but the molecular mechanism underlying its biological function is poorly understood. Here, we present evidence that the recombinant human Tim-Tipin complex (and Tim alone) markedly enhances the synthetic activity of DNA polymerase ε. In contrast, no significant effect on the synthetic ability of human DNA polymerase α and δ by Tim-Tipin was observed. Surface plasmon resonance measurements and co-immunoprecipitation experiments revealed that recombinant DNA polymerase ε directly interacts with either Tim or Tipin. In addition, the results of DNA band shift assays suggest that the Tim-Tipin complex (or Tim alone) is able to associate with DNA polymerase ε bound to a 40-/80-mer DNA ligand. Our results are discussed in view of the molecular dynamics at the human DNA replication fork.

Keywords: DNA Damage; DNA Enzymes; DNA Polymerase; DNA Repair; DNA Replication; DNA-Protein Interaction; Fork Protection Complex; Tim-Tipin Complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier Proteins* / chemistry
  • Carrier Proteins* / genetics
  • Carrier Proteins* / metabolism
  • Cell Cycle Proteins
  • Cell Line
  • DNA Polymerase II* / chemistry
  • DNA Polymerase II* / genetics
  • DNA Polymerase II* / metabolism
  • DNA* / biosynthesis
  • DNA* / chemistry
  • DNA* / genetics
  • DNA-Binding Proteins
  • Humans
  • Multiprotein Complexes* / chemistry
  • Multiprotein Complexes* / genetics
  • Multiprotein Complexes* / metabolism
  • Nuclear Proteins* / chemistry
  • Nuclear Proteins* / genetics
  • Nuclear Proteins* / metabolism
  • Surface Plasmon Resonance / methods


  • Carrier Proteins
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • Multiprotein Complexes
  • Nuclear Proteins
  • Tipin protein, human
  • DNA
  • DNA Polymerase II