1. Department of Cell Biology, Department of Dermatology, and Department of Anatomy, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606, Japan; Laboratory of Cell Biology, KAN Research Institute Inc., Minami-Kaneda, Suita, Osaka 564, Japan; and Department of Molecular Cell Biology, Institute of DNA Medicine, Jikei University School of Medicine, Nishi-Shinbashi, Minato-ku, Tokyo 105, Japan