1. Department of Physiology, Keimyung University School of Medicine, Daegu 704-701, Republic of Korea
2. Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea
3. School of Life Sciences, UNIST, Ulsan 689-798, Republic of Korea
4. Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea