Chief Scientist Laboratories Chromosome Dynamics Laboratory
Chief Scientist: Tatsuya Hirano (Ph.D.)
Research Summary

The duplication and segregation of the genome are two of the most fundamental events in cell reproduction. Our laboratory is interested in understanding the molecular mechanisms that regulate the faithful segregation of chromosomes during mitosis. By using a cell-free extract derived from Xenopus laevis (African toad) eggs, we have discovered two multiprotein complexes, condensin and cohesin, that play central roles in chromosome condensation and sister chromatid cohesion, respectively. At the heart of the two complexes lie members of a large family of chromosomal ATPases, the SMC (structural maintenance of chromosomes) family. Accumulating lines of evidence suggest that SMC proteins actively participate in many aspects of higher-order chromosome dynamics, including chromosome-wide gene regulation, DNA recombination /repair and meiotic chromosome segregation. The long-term goal in our laboratory is to understand how condensin and cohesin work at a mechanistic level in vitro, and how they interact with other proteins to execute their essential functions in vivo. We take multidisciplinary approaches toward this goal, including biochemistry, cell biology, structural biology and biophysics. Our research will contribute to a better understanding of human health because chromosome anomalies, such as aneuploidy and translocations, are tightly associated with tumor development and birth defects.
Main Research Fields
- Biology & Biochemistry
Related Research Fields
- Molecular Biology & Genetics
Research Subjects
- Chromosome architecture and segregation
- Molecular mechanisms of action of SMC protein complexes
- Chromosome dynamics and human disease
Selected Publications
- 1.
Hara, K., Kinoshita, K., Migita, T., Murakami, K., Shimizu, K., Takeuchi, K., Hirano, T., Hashimoto, H.:
"Structural basis of HEAT-kleisin interactions in the human condensin I subcomplex."
EMBO Rep. 20, e47183 (2019). - 2.
Sakai Y., Mochizuki, A., Kinoshita, K., Hirano, T., Tachikawa, M.:
"Modeling the functions of condensin in chromosome shaping and segregation."
PLoS Comp. Biol. 14(6), e1006152 (2018). - 3.Shintomi, K., and Hirano, T.:
“Mitotic chromosome assembly in vitro: functional cross talk between nucleosomes and condensins.”
Cold Spring Harbor Symp. Quant. Biol. doi:10.1101/sqb.2017.82.033639 (2017). - 4.Shintomi, K., Inoue, F., Watanabe, H., Ohsumi, K., Ohsugi, M., and Hirano, T.:
“Mitotic chromosome assembly despite nucleosome depletion in Xenopus egg extracts.”
Science 356, 1284-1287 (2017). - 5.Kamada, K., Su’etsugu, M., Takada, H., Miyata, M., and Hirano, T.:
“Overall shapes of the SMC-ScpB complex are determined by balance between constraint and relaxation of its structural parts.”
Structure 25, 603-616 (2017). - 6.Ono, T., Sakamoto, C., Nakao, M., Saitoh, N., and Hirano, T.:
“Condensin II plays an essential role in reversible assembly of mitotic chromosomes in situ.”
Mol. Biol. Cell. 28, 2875-2886 (2017). - 7.Kinoshita, K., and Hirano, T.:
“Dynamic organization of mitotic chromosomes.”
Curr. Opin. Cell Biol. 46, 46-53 (2017). - 8.Hirano, T.:
“Condensin-based chromosome organization from bacteria to vertebrates.”
Cell 164, 847-857 (2016). - 9.Shintomi, K., Takahashi, T. S., and Hirano, T.:
“Reconstitution of mitotic chromatids with a minimum set of purified factors.”
Nat. Cell Biol. 17, 1014-1023 (2015). - 10.Kinoshita, K., Kobayashi, T. J., and Hirano, T.:
“Balancing acts of two HEAT subunits of condensin I support dynamic assembly of chromosome axes.”
Dev. Cell 33, 94-106 (2015).
Recent Research Results
Jul. 21, 2017
Making do with less
Annual research report
Related Links
Lab Members
Principal investigator
- Tatsuya Hirano
- Chief Scientist
Core members
- Takao Ono
- Senior Research Scientist
- Kazuhisa Kinoshita
- Senior Research Scientist
- Keishi Shintomi
- Senior Research Scientist
- Shoji Tane
- Postdoctoral Researcher
- Makoto Kozai
- Postdoctoral Researcher
- Yuuki Aizawa
- Technical Staff II
Contact Information
2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Email: hiranot [at] riken.jp