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リエゾンラボ研究会
発表内容

Title:
Roles of Dynamin GTPase in membrane dynamics and actin dynamics

Kohji Takei
Department of Neuroscience, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences

Abstract:
 Cellular activity requires unceasing membrane deformations that include not only alterations of cell shape in the mitotic phase but also diverse intracellular membrane traffic in the interphase. Such membrane dynamics often implicates dynamin GTPases. Dynamins are large GTPases present not only in eukaryotes from yeast to mammals but also in plants, and they compose a protein superfamily. Dynamin functions in variety of membrane scission reactions, incding fission process of endocytic pit in endocytosis, fission of mitochondria, and late stage of cytokinesis. In membrane fission, dynamin polymerizes into a ring structure on the membrane, and conformational change of the polymerized dynamin upon GTP hydrolysis is thought to generate mechanical force to drive membrane scission. Furthermore, dynamin is implicated in the regulation of cytoskeletons including microtubules and actin. While dynamin is implicated in the regulation of microtubule dynamic instability, it plays a role in the formation and/or stabilization of actin bundles together with actin binding protein cortactin. Interestingly, the property of dynamin as a mechanochemical enzyme is essential also for the regulation of actin dynamics. In this seminar, I will discuss molecular mechanisms of dynamin in membrane dynamics and actin dynamics, focusing on dynamin 1, neuronal isoform of dynamin.

References:
Yamada, H., Abe, T., Satoh, A., Okazaki, N., Tago, S., Kobayashi, K., Yoshida, Y., Oda, Y., Watanabe, M., Tomizawa, K., Matsui, H., and Takei, K. (2013). Stabilization of actin bundles by a dynamin 1/cortactin ring complex is necessary for growth cone filopodia. The Journal of Neuroscience 33: 4514-4526.