1. Department of Molecular Biology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan.
2. Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Kawaguchi 332-0012, Japan.
3. Advanced Medical Research Center, Yokohama City University, Yokohama 236-0004, Japan.
4. Protein Research Network Co., Ltd., Yokohama 236-0004, Japan.
5. International Graduate School of Arts and Sciences, Yokohama City University, Yokohama 230-0045, Japan.
6. Department of Genetics, University of Wisconsin, Madison, WI 53706, USA.