Characterization of the rat carbonic anhydrase II gene structure: sequence analysis of the 5′ flanking region and 3′ UTR

The rat carbonic anhydrase II gene was characterized and found to be approximately 15.5 kb in length and to contain 7 exons and 6 introns. All intron/exon junction and branch point sequences conform to consensus sequences, and the overall rat CA II genomic structure appears to be conserved upon comparison with mouse, human, and chicken CA II genes. The putative cis-acting elements within the analyzed 1014 bp 5′ flanking region include: TATA box, 4 Sp1 binding sites, 2 AP2 sites and putative tissue-specific β-globin-like repeat elements. A CpG island of approximately 800 bp was identified that begins about 600 bp upstream of exon 1 and extends about 200 bp into intron 1. In the 3′ UTR, two polyadenylation signals (AATAAA) are present, the second of which is believed to be utilized. Northern blot analysis reveals that the 1.7 kb rat CA II mRNA is abundantly expressed in adult male brain and kidney, while negligible amounts are detected in heart and liver.