THE BOVINE GUANYLATE-CYCLASE GC-E GENE AND 5'-FLANKING REGION

The gene encoding the bovine guanylate cyclase isoform E (GC-E) was is olated as a single 18 kb genomic clone and shown to have 20 exons and 19 introns. Comparison of the structure of the GC-E gene with structur es of other membrane guanylate cyclase genes indicates that the GC-E i s most closely related to the subfamily of sensory guanylate cyclases. Comparison of the GC-E structure with that of the more distantly rela ted guanylate cyclase isoform A (GCA) gene shows the most divergence i n the extracellular and C-terminal regions, but general conservation o f introns and exons in the intracellular kinase-like and catalytic dom ains. RT-PCR from several bovine tissues shows that GC-E is expressed only in the retina. Consistent with this pattern of expression, elemen ts for the retinal-specific transcription factors RET-1, RET-2 and T a lpha-1 are located in the 5' flanking promoter region. (C) 1997 Elsevi er Science B.V.