1. Division of Biochemistry, Aichi Cancer Center Research Institute, Chikusa-ku, Nagoya 464-8681, Japan
2. Department of Cellular Oncology, Graduate School of Medicine, Nagoya University, Showa-ku, Nagoya 466-8550, Japan
3. Department of Biochemistry, Shimane University School of Medicine, Izumo 693-8501, Japan
4. RIKEN Center for Developmental Biology, Chuo-ku, Kobe 650-0047, Japan
5. Division of Virology, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan