Genomic organization of alpha 1 and beta 1 subunits of the mammalian soluble guanylyl cyclase genes

The structures of the genes encoding the alpha(1) and beta(1) subunits of m urine soluble guanylyl cyclase (sGC) were determined. Full-length cDNAs iso lated from mouse lungs encoding the alpha(1) (2.5 kb) and beta(1) (3.3 kb) subunits are presented in this report. The alpha(1) sGC gene is approximate ly 26.4 kb and contains nine exons. whereas the beta(1) sGC gene spans 22 k b and consists of 14 exons. The positions of exon/intron boundaries and the sizes of introns for both genes are described. Comparison of mouse genomic organization with the Human Genome Database predicted the exon/intron boun daries of the human genes and revealed that human and mouse alpha 1 and bet a(1) sGC genes have similar structures. Both mouse genes are localized on t he third chromosome, band 3E3-F1. and are separated by a fragment that is 2 % of the chromosomal length. The 5' untranscribed regions of alpha(1) and b eta(1) subunit genes were subcloned into luciferase reporter constructs, an d the functional analysis of promoter activity was performed in murine neur oblastoma N1E-115 cells. Our results indicate that the 5' untranscribed reg ions for both genes possess independent promoter activities and, together w ith the data on chromosomal localization, suggest independent regulation of both genes.