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Tomohiko Sugiyama, Ph.D.

Associate Professor

Biological Sciences 
Life Sciences Building 223


Education: Ph.D., Osaka University, Osaka, Japan


Research Interest:  Molecular mechanism of recombinational repair


We are studying the DNA homologous recombination, which is a key mechanism to repair a DNA double-strand break (DSB). DNA recombination is crucial to maintain genome integrity, prevent cancer development, and to segregate chromosomes in meiosis.

Biochemical detail of DNA recombination in eukaryotes is very complex. Nearly 20 years of aggressive studies revealed the basic framework of whole process, including well-coordinated actions of more (probably a lot more) than 10 enzymes. In addition, regulation of DNA recombination, including the cellular signaling that modulates repair machinery and controlling repair pathways, is not well understood. We are studying these fundamental mechanisms by using a simple unicellular eukaryote, yeast Saccharomyces cerevisiae as a model organism.

We are analyzing the activities of enzymes that are involved in the DNA recombination. No single enzyme can do whole recombination process alone. Instead, individual enzyme has one simple function (but not always easy to study). Many different enzymes collaborate all together to achieve really complex reactions, by interacting with DNA and other enzymes. We are reproducing these enzymatic reactions step by step, hoping to draw complete picture of DNA recombination in molecular level. 


Representative Publications:

  • Sugiyama, T. and Kantake, N. (2009) Dynamic Regulatory Interactions of Rad51, Rad52, and Replication protein-A in recombination intermediates. J. Mol. Biol. 390, 45-55
  • Wu, Y., Kantake, N, Sugiyama, T and Kowalczykowski, S. C. (2008) RAD51 protein controls RAD52-mediated DNA annealing. J. Biol. Chem. 283, 14883-14892
  • Sugiyama, T., Kantake, T., Wu Y., and Kowalczykowski, S. C. (2006) Rad52-mediated DNA annealing after Rad51-mediated DNA strand exchange promotes second ssDNA capture.  EMBO J. 25, 5539-5548
  • Kantake, N., Madiraju, M. V. V. M., Sugiyama, T., and Kowalczykowski, S. C. (2002) Escherichia coli RecO protein anneals ssDNA complexed with its cognate ssDNA-binding protein: A common step in genetic recombination Proc. of the Natl. Acad. Sci. USA, 99, 15327-15332
  • Sugiyama, T., New, J. H., and Kowalczykowski, S. C. (1998) DNA annealing by RAD52 protein is stimulated by specific interaction with the complex of replication protein A and single-stranded DNA  Proc. of the Natl. Acad. Sci. USA 95, 6049-6054.