UROGUANYLIN - CLONING OF PREPROUROGUANYLIN CDNA, MESSENGER-RNA EXPRESSION IN THE INTESTINE AND HEART AND ISOLATION OF UROGUANYLIN AND PROUROGUANYLIN FROM PLASMA

Uroguanylin is a small peptide isolated from opossum urine that activa tes membrane guanylate cyclases. We report the isolation by molecular cloning of cDNAs encoding the 109 amino acid preprouroguanylin contain ing the active uroguanylin peptide at its C-terminus. Preprouroguanyli n mRNAs of 1.2 kb were detected throughout the small and large intesti ne and in the atria and ventricles of heart, bur not in kidney, stomac h or liver. Transfection of COS-1 cells with the uroguanylin cDNA resu lted in prouroguanylin secretion. Both uroguanylin and prouroguanylin were isolated from opossum plasma. Thus, uroguanylin is made by the in testine and heart and circulates as a bioactive form of uroguanylin an d the inactive prouroguanylin. (C) 1996 Academic Press, Inc.