Urotensin II is the endogenous ligand of a G-protein-coupled orphan receptor, SENR (GPR14)

Two molecular species of urotensin II (UII) were isolated from porcine spin al cords and identified as the endogenous ligands of a G-protein-coupled or phan receptor, SENR (sensory epithelium neuropeptide-like receptor), which is :identical to GPR14. We established a CHO cell line stably expressing th e rat SENR and investigated several tissue extracts to evoke the response m ediated by the SENR. Extract from porcine spinal cords showed an. activity of arachidonic acid metabolites release from SENR-expressing cells and was purified using HPLC. Two active substances were isolated and their sequence s were determined as GPTSECFWKYCV and GPPSECFWKYCV, which were revealed to be porcine UII. Synthetic UII peptides caused arachidonic acid metabolites release activity in the rat SENR-expressing cells with an EC50 value of 1 n M. Three cDNAs encoding the precursor proteins of porcine UII were cloned f rom a porcine spinal cord cDNA library; 2 consist of 121 amino acid residue s and the other, which seemed to be a splicing variant, consist of 85 resid ues. (C) 1999 Academic Press.