1. Department of Biochemistry and Molecular BiologyKyoto Pharmaceutical UniversityKyoto607‐8414Japan
2. Department of Molecular Cell BiologyGraduate School of Pharmaceutical SciencesChiba UniversityChiba260‐8675Japan
3. Department of AnatomyAnthropology and Cell BiologyGraduate School of MedicineTohoku UniversitySendaiMiyagi980‐8575Japan