1. Laboratories for Biomolecular Networks, Graduate School of Frontier Biosciences, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan, Radioisotope Research Center, Osaka University, 2-4 Yamada-oka, Suita, Osaka 565-0871, Japan, and Nippon Medical School, Kanagawa, Japan