1. Department of Pharmacology, Kyoto University Faculty of Medicine, Kyoto 606-8315, Japan.
2. Central Laboratories for Key Technology, Kirin Brewery, Yokohama 236-0004, Japan.
3. Department of Biology, Faculty of Science, Chiba University, Chiba 263-8522, Japan.
4. Biological Institute, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.