1. Faculty of Pharmaceutical Sciences, Nagoya City University, Tanabedori, Mizuho-ku, Nagoya 467, Japan, Laboratory of Biochemistry, Aichi Cancer Center Research Institute, Kanokoden, Chikusa-ku, Nagoya 467, Japan, and Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, New York 11794-8651