Pronociceptin (PNOC)

Nociceptin (orphanin FQ), a neuropeptide of 17 amino acids, is the natural agonist of opioid receptor-like-1 (OPRL1), a G protein-coupled receptor whose human and murine cDNAs had previously been identified. This neuropeptide is endowed with pronociceptive activity in vivo. Nociceptin is derived from a larger precursor, prepronociceptin (PNOC) is highly conserved in the 3 species and displays organizational features that are strikingly similar to those for the genes for preproenkephalin, preprodynorphin, and preproopiomelanocortin. Mollereau et al. showed that the PNOC gene encodes a single copy of nociceptin as well as another peptide whose sequence is strictly conserved across murine and human species; hence, it is likely to be neurophysiologically significant.