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Chief Scientist Laboratories Cellular Informatics Laboratory

Chief Scientist: Yasushi Sako (D.Sci.)

Research Summary

Yasushi  Sako(D.Sci.)

Complex and flexible behaviors of living cells are outputs of intracellular signaling molecule systems. Unitary reactions in molecular systems are stochastic events, use energy as low as thermal fluctuation, and the average number of molecules involved is sometimes less than 100 suggesting significant number fluctuation in individual cells. Thus, molecular systems are suffering large fluctuations even though cells look like to be acting purposively searching both internal and external environments. Cells seem to have special mechanisms to suppress fluctuations but it is also possible that cells have evolved to use fluctuations positively. How fluctuating molecular systems determine complex and flexible cellular behaviors? We are developing single-molecule analysis technologies in living cells and trying to find the answer "goes down with" everyone.

Main Research Fields

  • Biology

Related Research Fields

  • Complex Systems
  • Biological Sciences
  • Biophysics


  • Intracellular Signal Transduction
  • Bioimaging

Selected Publications

Papers with an asterisk(*) are based on research conducted outside of RIKEN.

  • 1.Arata, Y., Hiroshima, M., Pack, C.-G., Ramanujam, R., Motegi, F., Nakazato, K., Wiseman, P. W., Sawa, H., Kobayashi, T. J., Brandão, H. B., Shibata, T., and *Sako, Y.:
    “Cortical polarity of the RING protein PAR-2 is maintained by exchange rate kinetics at the cortical-cytoplasm boundary”
    Cell Rep. 16, 2156-2168 (2016)
  • 2.Takanezawa, S., Morita, S.-i., Ozaki, Y., and Sako, Y.:
    “Raman spectral dynamics of single cells in the early stages of growth factor stimulation” Biophys. J. 108, 2148-2157 (2015)
  • 3.Mouri, K. and Sako, Y.:
    “Optimality conditions for cell-fate heterogeneity that maximize the effects of growth factors in PC12 cells”
    PLoS Comp. Biol. 9, e1003320 (2013).
  • 4.Hiroshima, M., Saeki, Y., Okada-Hatakeyama, M., and Sako, Y.:
    “Dynamically varying interactions between heregulin and ErbB proteins detected by single-molecule analysis in living cells”
    Proc. Natl. Acad. Sci. USA. 109, 13984-13989 (2012)
  • 5.Okamoto, K. and Sako, Y.:
    “Variational Bayes analysis of a photon-based hidden Markov model for single-molecule FRET trajectories”
    Biophys. J. 103, 1315-1324 (2012)
  • 6.Hibino, K., Shibata, T., Yanagida, T., and Sako, Y.:
    “Single-molecule kinetic analysis of RAF activation in the ternary complex among RAF, RasGTP, and the kinases on the plasma membrane of living cells”
    J. Biol. Chem. 286, 36460-36468 (2011)
  • 7.Morimatsu, M., Takagi, H., Ota, K. G., Iwamoto, R., Yanagida, T., Sako, Y.:
    “Multiple-state reactions between the epidermal growth factor receptor and Grb2 as observed using single-molecule analysis”
    Proc. Natl. Acad. Sci. USA, 104, 18013-18018 (2007)
  • 8.Teramura, Y., Ichinose, J., Takagi, H., Nishida, K., Yanagida, T., Sako, Y.:
    “Single-molecule analysis of epidermal growth factor binding on the surface of living cells”
    EMBO J., 25, 4215-4222 (2006)
  • 9.*Sako, Y., Yanagida, T.:
    “Single-molecule visualization in cell biology”
    Nature Rev. Mol. Cell Biol., 4, SS1-5 (2003)
  • 10.*Sako, Y., Minoguchi, S., Yanagida, T.:
    “Single molecule imaging of EGFR signal trasnduction on the living cell surface”
    Nature Cell Biol., 2, 168-172 (2000)

Recent Research Results

Annual research report

Related Links

Lab Members

Principal investigator

Yasushi Sako
Chief Scientist

Core members

Mitsuhiro Abe
Senior Research Scientist
Yukinobu Arata
Research Scientist
Takehiko Inaba
Research Scientist
Nobuhisa Umeki
Research Scientist
Kenji Okamoto
Senior Research Scientist
Nario Tomishige
Contract Researcher
Toshihiro Nagamine
Senior Research Scientist
Michio Hirosnima
Research Scientist
Ryo Maeda
Postdoctoral Researcher
Asami Makino
Contract Researcher
Motohide Murate
Research Scientist
Masataka Yanagawa
Research Scientist
Akihiro Yamamoto
Senior Technical Scientist
Toshihide Kobayashi
Senior Visiting Scientist
Changi Back
Visiting Scientist
Ryo Yoshizawa
Student Trainee
Hiromi Sato
Technical Staff II
Hiraku Miyagi
Technical Staff II
Toshiko Sawai

Contact Information

2-1 Hirosawa, Wako, Saitama 351-0198, Japan

Email: sako-lab [at] riken.jp