1. Department of Tumor Virology, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
2. Core Research for Evolutional Science and Technology, Japan Science and Technology Cooperation, Fukuoka 816-8580, Japan
3. Department of Structural Analysis, National Cardiovascular Center Research Institute, Osaka 565-8565, Japan
4. Laboratory of Molecular and Cellular Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan