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Revealing the Characteristics of "Brake" of Cell Movement (Press Release)

Release Date
07 Jul, 2010
  • BL26B1 (RIKEN Structural Genomics I)
A research group led by Shuichi Takeda, a scientist, and Yuichiro Maeda, a professor, of the Graduate School of Science, Nagoya University, succeeded in clarifying the mechanism of activity regulation of actin capping protein (CP), an important protein regulating cell movement, for the first time in the world.

Nagoya University
RIKEN
Tohoku University
Japan Science and Technology Agency

A research group led by Shuichi Takeda, a scientist, and Yuichiro Maeda, a professor, of the Graduate School of Science, Nagoya University, succeeded in clarifying the mechanism of activity regulation of actin capping protein (CP), an important protein regulating cell movement, for the first time in the world. This was achieved in cooperation with the research groups of Yasushi Nitanai, a senior research scientist at RIKEN SPring-8 Center, Motonori Ota, a professor of the Graduate School of Information Science, Nagoya University, and Toru Yamakuni, an associate professor of the Graduate School of Pharmaceutical Sciences, Tohoku University.

The cell movement of higher organisms is regulated by the polymerization and depolymerization of protein actin molecules. Actin serves as an "engine" that provides driving power and CP serves as a "brake" to regulate the movement. In this study, the mechanism of the "brake," which has scarcely been studied thus far, was clarified. The achievements of this research are very important in understanding the molecular movement of actin, a protein most abundant in cells, and are expected to contribute to research for the treatment of cancers and muscle disorders.

This study was carried out as part of Explanatory Research for Advanced Technology (ERATO), one of the Basic Research Programs of the Japan Science and Technology Agency (JST), with the title "Maeda Actin-Filament Dynamics" (Research Director: Professor Yuichiro Maeda). The results of this research were published online on 6 July 2010 in the American scientific journal PLoS Biology.

"Two Distinct Mechanisms for Actin Capping Protein Regulation - Steric and Allosteric Inhibition"
Shuichi Takeda, Shiho Minakata, Ryotaro Koike, Ichiro Kawahata, Akihiro Narita, Masashi Kitazawa, Motonori Ota, Tohru Yamakuni, Yuichiro Maéda, Yasushi Nitanai
PLoS Biology, 8 (7), e1000416 (2010), published online July 6, 2010.

<Figure>

Fig. 1
Fig. 1

(A) An actin filament is formed through the polymerization of actin molecules.
(B) Atomic structure of actin CP. The red area is the binding site of CP to the actin-filament end.
(C) CP inhibits the polymerization of actin by covering the actin-filament end.

Fig. 2
Fig. 2

(A) Atomic structure of CP/V-1 complex
(B) Atomic structure of CP/CARMIL complex

Fig. 3
Fig. 3

(A) It was found that CP is composed of two domains, shown in different colors.
(B) The two domains sway as they are twisted. This flexibility is considered to be important in the binding to the actin-filament end.

Fig. 4
Fig. 4

(A) CP strongly binds to the actin-filament end through the twisting motion between the two domains of CP.
(B) CARMIL removes CP from the actin-filament end by binding with CP to make CP incompatible with actin-filament end.
(C) Because V-1 directly covers the binding site of CP to actin, CP bound with V-1 cannot bind with the actin filament.


For more information, please contact:
Dr. Shuichi Takeda (Nagoya University)
E-mail: mail

Prof. Yuichiro Maeda (Nagoya University)
E-mail: mail

Prof. Tomonori Ohta (Nagoya University)
E-mail: mail

Associate Prof. Toru Yamakuni (Tohoku University)
E-mail: mail

Dr. Yasushi Nitanai (RIKEN)
E-mail: mail