GENOMIC SEQUENCE OF THE MURINE GUANYLIN GENE

Guanylin, a 15-amino-acid peptide, is an endogenous ligand of the inte stinal receptor guanylate cyclase-C. After binding to this receptor, g uanylin increases the intracellular concentration of cyclic GMP and in duces chloride secretion. We have isolated a genomic clone containing the entire murine guanylin gene. The guanylin gene is composed of thre e exons that span 1700 bp. The first 133 nucleotides of upstream promo ter sequence lack the canonical TATA, CAAT, and SP1 elements. Guanylin transcription is nearly exclusively limited to the intestine, and the presence of guanylin mRNA is greatest in the distal colon and ileum. Therefore, characterization of the guanylin promoter is likely to prov ide another paradigm for intestine-specific gene regulation. (C) 1994 Academic Press, Inc.