Core division
Masayuki Takahashi

PhD 1984, Toulouse University (France)
E-mail: takahashi.m.ay(at)
Office: Room304, M3 building, Ookayama campus

Areas of Research: Homologous recombination, anticancer drug development, protein/protein interaction, protein/DNA interaction

Keywords: DNA repair, RecA family proteins, protein dynamics, optical spectroscopy

Research interest:

Homologous recombination, exchange of DNA strands between two homologous DNA, is a universal process exiting from bacteria to human. It creates gene diversity and is involved in repair of DNA damages. Both defect and excess of the reaction promote cancer formation. The reaction is also exploited in biotechnology and biomedicine such as gene therapy for integrate the correctional DNA to the mutated gene.
The reaction is catalyzed by RecA family protein (RecA in prokaryotes, Rad51 in eukaryotes and RadA in archaea). For the reaction, many molecules of RecA protein (or its homolog) bind to a single-stranded part of DNA in a cooperative manner and form a long helical filament. This filament find out the part of double-stranded DNA which has the same sequence as the single-stranded DNA and promotes strand exchange with hydrolysis of ATP. We don't know yet how RecA finds out homologous double-stranded DNA and promotes the strand exchange between them and what the role of ATP hydrolysis. Since the reaction occurs in a small part of long filament, experimental analysis of the reaction is difficult and cannot be done by classical biochemical analysis.
We have determined the structure of single-stranded/RecA (and Rad51) complex filament by combining optical spectroscopy (linear dichroism), mutation analysis and molecular modelling. For further analysis, we use synthetic biology approach: we search possible reaction mechanisms from the structure of this complex by using molecular dynamics and modelling and then test the models by using mutated proteins and by using modified DNAs, which are predicted to discriminate the models. We also study the effect of regulatory proteins, which stimulates the reaction, on the structure of RecA (Rad51)/DNA complex and the kinetics of reaction.

Selected publications

  1. H. Fornander, A. Renodon-Corniere, N. Kuwabara, K. Ito, Y. Tsutsui, T. Shimizu, H. Iwasaki, B. Norden & M. Takahashi*, Swi5-Sfr1 protein stimulates Rad51-mediated DNA strand exchange reaction through organization of DNA bases in the presynaptic filament, Nucleic Acids Res. 42, 2358–2365 (2014)
  2. R. Berges, J. Balzeau, M. Takahashi*, C. Prevost & J. Eyer, Structure-function analysis of the anti-glioblastoma NFL-TBS.40-63 peptide corresponding to the tubulin-binding site on the light neurofilament subunit, PlosOne 7, e49436 (2012)
  3. L. H. Fornander, K. Frykholm A. Reymer, A. Renodon-Cornière, M. Takahashi* & B. Nordén, Ca2+ improves organization of single-stranded DNA bases in human Rad51 filament, explaining stimulatory effect on gene recombination, Nucleic Acids Res. 40, 4904-4913 (2012)
  4. J. Nomme, A Renodon-Cornière, Y. Asanomi, K. Sakaguchi, A. Z. Stasiak, A. Stasiak, B. Norden, V. Tran & M. Takahashi*, Design of potent inhibitors of human RAD51 recombinase based on BRC motifs of BRCA2 protein: modeling and experimental validation of a chimera peptide, J. Med. Chem. 53, 5782-5791 (2010)
  5. H. Arata, A. Dupont, J. Miné-Hattab, A. Renodon-Cornière, M. Takahashi*, J.-L. Viovy & G. Cappello, Direct observation of twisting steps during Rad51 polymerization on DNA, Proc. Natl. Acad. Sci. USA 106, 19239-1244 (2009)
  6. Structure of human Rad51 protein filament from molecular modeling and site-specific linear dichroism spectroscopy
    A. Reymer, K. Frykholm, K. Morimatsu, M. Takahashi* & B. Norden
    Proc. Natl. Acad. Sci. USA 106, 13248-13253 (2009))
  7. C. Prévost, M. Takahashi* & R. Lavery, Deforming DNA: from physics to biology, ChemPhysChem 10, 1399-1404 (2009))
  8. A. Renodon-Cornière, Y. Takizawa, S. Conilleau, H. Kurumizaka & M. Takahashi, Structural analysis of the human Rad51 protein-DNA complex filament by tryptophan fluorescence scanning analysis: transmission of allosteric effects between ATP binding and DNA binding, J. Mol. Biol. 383, 575-587 (2008))
  9. C. Esnault, A. Renodon-Cornière, M. Takahashi*, N. Casse, N. Delorme, G. Louarn, F. Fleury, J.-F. Pilard & B. Chénais, DNA binding of human Rad51 protein assessed by Quartz Crystal Microbalance and Atomic Force Microscopy: effect of ADP and BRC4-28 peptide inhibitor, ChemPhysChem (2014) in press
  10. A. LE CIGNE, V. MENIL-PHILIPPOT, F. FLEURY, M. TAKAHASHI* & C. THIRIET, A transient expression of RAD51 in the late G2-phase is required for cell cycle progression in synchronous Physarum cells, Genes to Cells (2014) in press

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