2003 - Ph.D. Bioengineering, Soka Univ., Tokyo, Japan
1996 - M. Eng. Bioengineering, Soka Univ., Tokyo, Japan
Function and regulation of cell motility and intracellular trafficking in particular, focusing on the control of the motor proteins in various aspects of cell motility activities.
- Characterization of unconventional myosins (IIIA, VIIA, X, etc.)
Motor proteins represent the fundamental source of motive force in living systems. The malfunction of these myosins causes various diseases, such as cardiomyopathy, human deafness and blindness, neurodegenerative diseases such as Alzheimer's, Griscelli disease, cancer invasion and metastasis, etc. Our research focuses on the physiological function and regulation of motor proteins to uncover the mechanism of various important human diseases.
Recent progress of myosin research has raised a hypothesis that each myosin has unique motor characteristics, specific docking partners and has a specific cellular function. The motor activity can be regulated by various mechanisms such as cargo-induced conformational changes, dimerization, phosphorylation, calcium signaling, etc. Our interest is to clarify the regulation mechanism of each myosin-based motility event using biochemical, molecular biological, and cell biological methods.
Byung Chull An, Tsuyoshi Sakai, Shigeru Komaba, Hiroko Kishi, Sei Kobayashi, Jin Young Kim, Reiko Ikebe, and Mistuo Ikebe (2014) Phosphorylation of the kinase domain regulates autophosphorylation of myosin IIIA and its translocation in microvilli. Biochemistry, 53 7835-7845.
Umeki N, Jung HS, Sakai T, Sato O, Ikebe R, Ikebe M (2011) Phospholipid-dependent regulation of the motor activity of myosin X. Nat Struct Mol Biol 18: 783-788.
Sakai T, Umeki N, Ikebe R, Ikebe M (2011) Cargo binding activates myosin VIIA motor function in cells. Proc Natl Acad Sci U S A, 108: 7028-7033.
Engel, B.D., Lechtreck, K.F., Sakai, T., Ikebe, M., Witman, G.B. and Marshall, W.F. (2009) Total internal reflection fluorescence (TIRF) microscopy of Chlamydomonas flagella. Methods Cell Biol, 93, 157-177.
Umeki, N., Jung, H.S., Watanabe, S., Sakai, T., Li, X.D., Ikebe, R., Craig,R. and Ikebe, M. (2009) The tail binds to the head-neck domain, inhibiting ATPase activity of myosin VIIA. Proc Natl Acad Sci U S A, 106, 8483-8488.
Lechtreck, K.F., Johnson, E.C., Sakai, T., Cochran, D., Ballif, B.A., Rush, J., Pazour, G.J., Ikebe, M. and Witman, G.B. (2009) The Chlamydomonas reinhardtii BBSome is an IFT cargo required for export of specific signaling proteins from flagella. J Cell Biol, 187, 1117-1132.