Centers & Labs

RIKEN Quantitative Biology Center

Laboratory for Cell Polarity Regulation

Team Leader: Yasushi Okada (M.D., Ph.D.)
Yasushi  Okada(M.D., Ph.D.)

Our work has focused on in vitro studies of the single molecule motors. We have combined single molecule imaging, gene manipulation, and structural biology techniques to study the mechanisms responsible for such function. Currently we are attempting to extend our methods to observe such function intracellularly to confirm the regulating mechanism(s). Motor proteins transport a variety of elements inside the cell. In fact, so important is this transport that it is not an exaggeration to describe it as the lifeline of a cell. When a motor malfunctions, the cell's internal navigation system becomes disabled so that transport is compromised. We are studying the navigation system by directly observing transportation using new imaging techniques and the motor protein kinesin KIF5, a key regulator for axonal development, as our model. Despite neurons extending a large number of projections, only one becomes an axon. Recently, we have discovered that the structures of the microtubules on which kinesins travel in dendrites and the axon are different. KIF5 can recognize the structural difference between these microtubules and therefore be used to determine which neural projections become the axon and which become dendrites.

Keywords

  • Live cell imaging
  • molecular motor
  • Cytoskeleton
  • Superresolution microscopy
  • single molecule measurement

Selected Publications

Papers with an asterisk(*) are based on research conducted outside of RIKEN.
  1. Takai, A., Nakano, M., Saito, K., Haruno, R., Watanabe, T. M., et al.:
    "Expanded palette of Nano-lanterns for real-time multicolor luminescence imaging"
    Proc. Natl. Acad. Sci. U.S.A. 112, 4352-4356 (2015)
  2. Hayashi, S. & Okada, Y.:
    "Ultrafast superresolution fluorescence imaging with spinning disk confocal microscope optics "
    Mol. Biol. Cell 26, 1743-1751 (2015)
  3. Okada, Y. & Nakagawa, S.:
    "Super-resolution imaging of nuclear bodies by STED microscopy"
    Methods Mol. Biol. 1262, 21-35 (2015)
  4. Uno, S., Kamiya, M., Yoshihara, T., Sugawara, K., Okabe, K., et al.:
    "A spontaneously blinking fluorophore based on intramolecular spirocyclization for live-cell super-resolution imaging"
    Nat. Chem. 6, 681-689 (2014)
  5. *Yajima, H., Ogura, T., Nitta, R., Okada, Y., Sato, C. & Hirokawa, N.:
    "Conformational changes in tubulin in GMPCPP and GDP-taxol microtubules observed by cryoelectron microscopy "
    J. Cell Biol. 198, 315-322 (2012)
  6. *Hirokawa, N., Tanaka, Y. & Okada, Y.:
    "Cilia, KIF3 molecular motor and nodal flow "
    Curr. Opin. Cell Biol. 24, 31-39 (2012)
  7. *Nakata, T., Niwa, S., Okada, Y., Perez, F. & Hirokawa, N.:
    "Preferential binding of a kinesin-1 motor to GTP-tubulin-rich microtubules underlies polarized vesicle transport "
    J. Cell Biol. 194, 245-255 (2011)
  8. *Hirokawa, N., Nitta, R. & Okada, Y.:
    "The mechanisms of kinesin motor motility: lessons from the monomeric motor KIF1A "
    Nat. Rev. Mol. Cell Biol. 10, 877-884 (2009)

Lab Members

Principal Investigator

Yasushi Okada
Team Leader

Core Members

Kazuho Ikeda
Research Scientist
Taketoshi Kambara
Research Scientist
Hideyuki Yaginuma
Research Scientist
Akira Takai
Special Postdoctoral Researcher
Kazunari Mouri
Special Postdoctoral Researcher
Yoko Terahara
Postdoctoral Researcher
Daisuke Ino
Postdoctoral Researcher
Takumi Chinen
Postdoctoral Researcher
Tetsuro Ariyoshi
Postdoctoral Researcher
Shang Xu Dan
Technical Staff I
Junko Asada
Technical Staff I
Nozomi Furutani
Technical Staff II