Tomohiko Sugiyama

Assistant Professor

Department of Biological Sciences,

Ohio University

Life Science Research Facility - Rm. 211

Athens, OH 45701

TEL: 740-597-1927

E-Mail: sugiyama@ohio.edu

Research interest

DNA recombination is a major mechanism to repair DNA double-strand breaks.

I am interested in biochemical mechanisms of DNA recombination.

DNA Double-Strand Break Repair in Growing Cells

DNA is constantly exposed to natural and artificial damaging agents such as irradiation and chemicals. Without prompt repair of such damages, cells will die or develop cancer. One of the most devastating damage is DNA double-strand breaks (DSBs). DSBs are repaired by a specialized pathway that utilizes homologous recombination machinery, called DSB repair. I am interested in studying this DSB repair pathway at molecular level.

(see more... under construction)

Meiotic DNA Recombination

DNA recombination is crucial for meiosis. In most organisms, including humans, DNA recombination is essential to divide homologous chromosome into germ cells. The failure of meiotic DNA recombination results in chromosomal disorders such as Down’s syndrome in humans. Meiotic DNA recombination uses many of the recombination proteins for DSB repair, plus several additional proteins. Therefore, studying meiotic recombination is connected to the study of DSB repair.

(What is meiosis? ... under construction)

The goal of our study is to understand the mechanism of meiotic recombination. Currently, we focus on two important steps,

1) How DNA recombination is initiated?

(see more... under construction)

2) How homologous DNA molecules exchange their DNA strand?

(see more... under construction)

Research Methods

We use purified proteins to analyze their activities in various reactions of DNA recombination. We are mainly using yeast Saccharomyces cerevisiae as a model organism. However, our research is motivated by the interest in biological events, not in specific organism.

Courses Teaching

Bios225 (Genetics of Human Society)

Bios 320 (Fundamentals of Animal Cell Biology)

Bios 489 (Microbial Physiology Lecture and Lab.)

Graduate Programs

Molecular and Cellular Biology Graduate Program

Lab member

Noriko Kantake (Post-doc)

Publications

Wu, Y., Sugiyama, T., Siino, J., and Kowalczykowski, S. C. (2006)

The DNA binding preference of Rad52 and Rad59 proteins: Implications for their function in homologous recombination

J. Biol. Chem. 281, 40001-40009

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

Wu, Y., Sugiyama, T., and Kowalczykowski, S. C. (2006)

DNA annealing mediated by Rad52 and Rad59 proteins

J. Biol. Chem. 281, 15441–15449

Kantake, N., Sugiyama, T., Kolodner, R. D., and Kowalczykowski, S. C. (2003)

The Recombination-deficient Mutant RPA (rfa1-t11) Is Displaced Slowly From Single-stranded DNA by Rad51 Protein

J. Biol. Chem. 278, 23410-23417

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., and Kowalczykowski, S. C. (2002)

Rad52 protein associates with RPA-ssDNA to accelerate Rad51-mediated displacement of RPA and presynaptic complex formation.

J. Biol. Chem. 277, 31663-31672

Solinger, J. A., Lutz, G., Sugiyama, T., Kowalczykowski, S. C., Heyer, W. (2001)

Rad54 Protein Stimulates Heteroduplex DNA Formation in the Synaptic Phase of DNA Strand Exchange via Specific Interactions with the Presynaptic Rad51 Nucleoprotein Filament

Journal of Molecular Biology 307, 1207-1221.

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.

New, J. H., Sugiyama, T., Zaitseva, E., and Kowalczykoswki, S. C. (1998)

Rad52 protein stimulates DNA strand exchange by Rad51 and replication protein A

Nature (London) 391, 407-410.

Sugiyama, T., Zaitseva, E. M., and Kowalczykowski, S. C. (1997)

A single-stranded DNA-binding protein is needed for efficient presynaptic complex formation by the Saccharomyces cerevisiae Rad51 protein.

J. Biol. Chem. 272, 7940-7945.

Sugiyama, T., Suzue, K., Okamoto, M., Inselburg, J., Tai, K., and Horii, T. (1996)

Production of recombinant SERA proteins of Plasmodium falciparum in E. coli by using synthetic genes.

Vaccine 14, 1069-1076.

Yasueda, H., Takechi, S., Sugiyama, T., and Itoh T. (1994)

Control of ColE2 plasmid replication: Negative regulation of the expression of the plasmid-specific initiator protein, Rep, at a posttranscriptional step.

Mol. Gen. Genet. 244, 41-48.

Hiraga, S., Sugiyama, T., and Itoh, T. (1994)

Comparative analysis of the replicon regions of ColE2-related plasmids.

J. Bacteriol. 176, 7233-7243

Sugiyama, T. and Itoh, T. (1993)

Control of ColE2 DNA replication: in vitro binding of the antisense RNA to the Rep mRNA.

Nucl. Acid Res. 21, 5972-5977