Alternative promoter usage and tissue specific expression of the mouse somatostatin receptor 2 gene.

We have cloned the 5' upstream regulatory region of the mouse somatostatin receptor 2 gene. Its genomic organization is novel among all somatostatin receptor genes. It contains two previously unrecognized exons, separated by introns larger than 25 kb, and three tissue and cell specific alternative promoters. The first promoter in front of exon 1 is active only in AtT-20 tumor cells. The second promoter, located 5' to exon 2, is used in brain, pituitary, adrenals, pancreas, NG 108-15 and AtT-20 cells. Furthermore, it contains putative DNA elements for regulation by glucocorticoids, estradiol and cAMP. A third promoter, located in exon 3, is additionally used in lung, kidney and spleen.