1. Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan, Tsukuba Proteomics Research Center, SHIMADZU BIOTECH, 3-17-1 Azuma, Tsukuba 305-0031, Japan, Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan, and Radiation Biology Center, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan