1. Institute for Protein Research, Osaka University, and CREST, Japan Science and Technology Agency, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan, Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, Andhra Pradesh, India, and Department of Molecular Physiology, Faculty of Medical Science, University of Fukui, and CREST, Japan Science and Technology Agency, Matsuoka, Fukui 910-1193, Japan