Structure of human ornithine decarboxylase antizyme 2 gene.

Ornithine decarboxylase antizyme 1, a negative regulator of polyamine levels, acts by destabilizing the first enzyme in the polyamine biosynthetic pathway (ODC) and by inhibiting uptake of polyamines. Recently, a second mammalian antizyme was discovered. Here, we report the genomic organization and chromosomal position of the new human gene, HuAZ2, and make a comparison with its antizyme 1 homologue. Fluorescence in-situ hybridization (FISH) localized the sequences from a bacterial artificial chromosomal (BAC) clone containing HuAZ2 at band 22 of the long arm of chromosome 15. This gene spans at least 15kb and contains five exons. No CAAT or TATA sequences could be identified within 800bp upstream of the translation initiation codon, but the 5'-flanking region contains several putative binding sites for other transcription factors. Transcription initiation of this gene appears to be heterogeneous.