Characterization of the human antizyme gene.

Antizyme is a polyamine-inducible protein involved in feedback regulation of cellular polyamine levels. Recently, we isolated genomic clones for the human antizyme gene and determined its chromosomal location (Matsufuji et al., Genomics 38 (1996) 112-114). In the present study, we report complete nucleotide sequence and organization of the human antizyme gene. The organizations of human and rat genes are very similar, but their introns show divergency in terms of the length and nucleotide sequence. Luciferase reporter assay revealed that the 5'-flanking region of the human gene had a strong transcriptional activity in NIH-3T3 with and without addition of spermidine. The promoter was also effective in transfected COS7 and HeLa cells. A 223-bp region at the proximity of the transcriptional start points carries several regulatory sequence motifs including a TATA box, CAAT boxes and GC boxes, and was shown to be important for the strong transcriptional activity.