Laboratory for Molecular Biophysics

In neuronal axons, transport of vesicles is mediated by motor proteins such as kinesin and dynein. Our recent results have revealed that microtubules, which have been previously considered as merely a passive track for kinesin, are not actually passive: during the movement of kinesin, microtubules dynamically change their structure over a long range of microns in length. The result implicates a possibility that the state transition of microtubules may play an important role in the mechanism of motility. Our research goal is to understand the molecular mechanism underlying the state transition of microtubules, and elucidate how it is involved in the motility of motor proteins.

Research Subjects

• Molecular analysis of tubulin structure
• Electrodynamic properties of microtubules
• Analysis of the stochastic motion of molecules using single molecule imaging technique

Publications

1. Uchimura, S., Oguchi, Y., Hachikubo, Y., Ishiwata, S., and Muto, E.:
   "Key residues on microtubule responsible for activation of kinesin ATPase."
   EMBO. J., 29, 1167-1175, (2010).
2. Minoura, I., Katayama, E., Sekimoto, K., and Muto, E.:
   "One-dimensional Brownian motion of charged nanoparticles along microtubules: A model system for weak binding interactions."
   Biophys J., 98, 1589-1597, (2010).
3. Uchimura, S., Oguchi, Y., Katsuki, M., Usui, T., Osada, H., Nikawa, J-I., Ishiwata, S., and Muto, E.:
   "Identification of a strong binding site for kinesin on the microtubule using mutant analysis of tubulin."
   EMBO. J., 25, 5932-5941 (2006).
4. Minoura, I., and Muto, E.:
   "Dielectric measurement of individual microtubules using the electroorientation method."
   Biophys J., 90, 3739-3748 (2006).
5. Muto, E., Sakai, H., and Kaseda, K.:
   "Long range cooperative binding of kinesin to a microtubule in the presence of ATP"
   J. Cell Biol., 168, 691-696 (2005).