Kyushu University Academic Staff Educational and Research Activities Database
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Eiji Ohashi Last modified date:2018.06.20

Assistant Professor / Integrative biology
Department of Biology
Faculty of Sciences

Graduate School
Undergraduate School

Homepage of Chromosome Function .
Academic Degree
Ph. D. (Dr. of Sci.)
Country of degree conferring institution (Overseas)
Field of Specialization
Molecular Biology
ORCID(Open Researcher and Contributor ID)
Total Priod of education and research career in the foreign country
Research Interests
  • Functional analysis of Rad9-Hus1-Rad1 (9-1-1) DNA damage response complex
    keyword : DNA damage response, checkpoint
    2008.10~2018.03Interaction between Rad9 and TopBP1 Phenotypic analysis of cells overexpressing mutant Rad9.
Academic Activities
1. Ohashi E, Multiple regulatory roles of Rad9 C-tail in DNA damage responses, Journal of Rare Disease Research and Treatment, 2017.04.
2. Ohashi E, Tsurimoto T, Functions of Multiple Clamp and Clamp-Loader Complexes in Eukaryotic DNA Replication, DNA Replication, Advances in Experimental Medicine and Biology, 2017.01.
3. Ohmori H, Hanafusa T, Ohashi E, Vaziri C., Separate roles of structured and unstructured regions of Y-family DNA polymerases., Adv Protein Chem Struct Biol., 2009.11.
1. Fujisawa R, Ohashi E, Hirota K, Tsurimoto T., Human CTF18-RFC clamp-loader complexed with non-synthesising DNA polymerase ε efficiently loads the PCNA sliding clamp., Nucleic Acids Research, 45: 4550-4563, 2017.05, The alternative proliferating-cell nuclear antigen (PCNA)-loader CTF18-RFC forms a stable complex with DNA polymerase ε (Polε). We observed that, under near-physiological conditions, CTF18-RFC alone loaded PCNA inefficiently, but loaded it efficiently when complexed with Polε. During efficient PCNA loading, CTF18-RFC and Polε assembled at a 3΄ primer-template junction cooperatively, and directed PCNA to the loading site. Site-specific photo-crosslinking of directly interacting proteins at the primer-template junction showed similar cooperative binding, in which the catalytic N-terminal portion of Polε acted as the major docking protein. In the PCNA-loading intermediate with ATPγS, binding of CTF18 to the DNA structures increased, suggesting transient access of CTF18-RFC to the primer terminus. Polε placed in DNA synthesis mode using a substrate DNA with a deoxidised 3΄ primer end did not stimulate PCNA loading, suggesting that DNA synthesis and PCNA loading are mutually exclusive at the 3΄ primer-template junction. Furthermore, PCNA and CTF18-RFC-Polε complex engaged in stable trimeric assembly on the template DNA and synthesised DNA efficiently. Thus, CTF18-RFC appears to be involved in leading-strand DNA synthesis through its interaction with Polε, and can load PCNA onto DNA when Polε is not in DNA synthesis mode to restore DNA synthesis..
2. Okimoto H, Tanaka S, Araki H, Ohashi E, Tsurimoto T., Conserved interaction of Ctf18-RFC with DNA polymerase ε is critical for maintenance of genome stability in Saccharomyces cerevisiae., Genes to Cells, 21: 482-491, 2016.05.
3. Takeishi Y, Iwaya-Omi R, Ohashi E, Tsurimoto T, Intramolecular binding of the Rad9 C terminus in the checkpoint clamp Rad9-Hus1-Rad1 is closely linked with its DNA binding., Journal of Biological Chemistry, 19923-19932, 290: 19923-19932, 2015.08.
4. Ohashi E, Takeishi Y, Ueda S, Tsurimoto T, Interaction between Rad9-Hus1-Rad1 and TopBP1 activates ATR-ATRIP and promotes TopBP1 recruitment to sites of UV-damage., DNA repair, 1-11, 21: 1-11, 2014.09.
5. Ueda S, Takeishi Y, Ohashi E, Tsurimoto T., Two serine phosphorylation sites in the C-terminus of Rad9 are critical for 9-1-1 binding to TopBP1 and activation of the DNA damage checkpoint response in HeLa cells., Genes to Cells, 807-816, 17: 807-816, 2012.10.
6. Takeishi Y, Ohashi E, Ogawa K, Masai H, Obuse C, Tsurimoto T., Casein kinase 2-dependent phosphorylation of human Rad9 mediates the interaction between human Rad9-Hus1-Rad1 complex and TopBP1., Genes to Cells, 15: 761-771, 2010.06.
7. Ohashi E, Hanafusa T, Kamei K, Song I, Tomida J, Hashimoto H, Vaziri C, Ohmori H., Identification of a novel REV1-interacting motif necessary for DNA polymerase kappa function., Genes to Cells, 14:101-11, 2009.02.
8. Ohashi E, Murakumo Y, Kanjo N, Akagi J, Masutani C, Hanaoka F, Ohmori H., Interaction of hREV1 with three human Y-family DNA polymerases., Genes to Cells, 523-531, 9: 523-531, 2004.06.
9. Ohashi E, Bebenek K, Matsuda T, Feaver WJ, Gerlach VL, Friedberg EC, Ohmori H, Kunkel TA., Fidelity and processivity of DNA synthesis by DNA polymerase kappa, the product of the human DINB1 gene., Journal of Biological Chemistry, 39678-39684, 275: 39678-39684, 2000.12.
10. Ohashi E, Ogi T, Kusumoto R, Iwai S, Masutani C, Hanaoka F, Ohmori H., Error-prone bypass of certain DNA lesions by the human DNA polymerase kappa., Genes and Development, 1589-1594, 14: 1589-1594, 2000.07.
1. Eiji Ohashi, Yukimasa Takeishi, Satoshi Ueda, and Toshiki Tsurimoto, Roles of the 9-1-1/TopBP1 interaction for DNA damage responses in human cells, 第34回日本分子生物学会, 2011.12.
2. Eiji Ohashi, Yukimasa Takeishi, Nao Mori, Tatsuya Kasugaya, and Toshiki Tsurimoto, CK2 phosphorylates Rad9 and facilitates the interaction between 9-1-1 and TopBP1, International Conference on Radiation and Cancer Biology 2010 at Nagasaki, 2010.02.
3. Eiji Ohashi, Yukimasa Takeishi, Tatsuya Kasugaya, Nao Mori, and Toshiki Tsurimoto, The phosphorylation of Rad9 at Ser-341 and Ser-387 by CK2 promotes the interaction between 9-1-1 and TopBP1, Cold Spring Harbor Laboratory Meeting on “Eukaryotic DNA replication and genome maintenance”, 2009.09.
Educational Activities
Practical courses for University students and Department of Biology, Faculty of Science.
Supervision of students in our lab.