Shin'ya Kimura

GAK: a cyclin G associated kinase contains a tensin/auxilin-like domain.

We have cloned a cDNA encoding a novel association partner of cyclin G by West‐Western blotting. The cDNA encodes a protein that harbors a Ser/Thr protein kinase‐like catalytic domain at the N‐terminal. Hence, we named it GAK (cyclin ‐ ssociated inase). The long C‐terminal extension shares homology with tensin and auxilin, and contains a leucine zipper region. Co‐immunoprecipitation and Western blotting showed that GAK and cyclin G associate together in vivo. GAK also co‐precipitated with CDK5, and CDK5 was found to be associated with cyclin G. We also showed by BIAcore analysis that the GAK‐cyclin G interaction was direct.

Cyclin G1 associates with MDM2 and regulates accumulation and degradation of p53 protein

Background: Cyclin G1 is a transcriptional target of p53 and is induced by DNA damage in a p53 dependent manner. Analysis of cyclin G1 disrupted mice demonstrated that cyclin G1 is involved in many of the functions regulated by p53 such as apoptosis, growth control and check point regulation in response to DNA damage. The results suggest that the main role of cyclin G1 is to mediate or regulate the function of p53.

DEVELOPMENT OF HIGH-PERFORMANCE MR ACTUATOR AND ITS APPLICATION TO 2-D FORCE DISPLAY

Force display systems are a kind of robot systems, which share the space with people while they are working, and which directly touch and display force-senses to their users. For such a robot system, it is important to estimate safety quantitatively and to assure mechanically safety. The safety can be assured by using MR actuator because MR actuator is one of clutch type actuators. And, the features of MR actuator are very preferable to those of ER actuator and other clutch type actuators, to improve the performance of force display systems. In this study, we developed an MR actuator with low inertia, high torque/inertia ratio and high responsibility. Then, a 2-D force display system using the MR actuator was developed. The characteristics of the MR actuator that are low inertia, high torque/inertia ratio and high responsibility contribute to improve the performance of force display systems.

High-performance 2-D force display system using MR actuators

A force display system is a kind of human-coexistent robot systems, which share the space with people while they are working, and which directly touch and display force-senses to their users. For such a robot system, it is important to estimate safety quantitatively and to ensure mechanical safety. In this paper, it is described that using MR (magneto-rheological) actuators, which is one clutch type actuators, can ensure safety. Moreover, the characteristics of MR actuators that are low inertia, high torque/inertia ratio and high responsibility contribute to improve the performance of force display systems. In this study, we developed an MR actuator with low inertia (2.6/spl times/10/sup -5/[kg/spl middot/ m/sup 2/]), high torque/inertia ratio (3.8/spl times/10/sup 5/[1/s/sup 2/]) and high responsibility. Torque/inertia ratio of this MR actuator is highest among MR actuators developed so far and much higher than those of conventional servo actuators. Then, a high-performance 2-D force display system using the MR actuator was developed. Maximum force displayed is 190 [N] and rigidity of the system is 5.9 [N/mm]. Moreover, backdrivability, dynamic range and collision sense are improved by using MR actuators in comparison with a system using ER actuators.