ECE2007 Symposia Novel bioactive peptides – lessons from animals (4 abstracts)
1INSERM U413, Laboratory of Cellular and Molecular Neuroendocrinology, IFRMP23, University of Rouen, Mont-Saint-Aignan, France; 2INRS Institut Armand-Frappier, Univeristy of Québec, Montreal, Canada; 3Department Biochemistry, Faculty Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates.
The concentration of many neuropeptides in the brains of ectothermic vertebrates is several orders of magnitude higher than in the brains of mammals. We have taken advantage of this singular situation to isolate from the brain of the European green frog, Rana esculenta, a number of regulatory peptides that are orthologous to mammalian neuroendocrine peptides. These include α-MSH, γ-MSH, two tachykinins, two GnRH variants, CRH, PACAP, NPY, CGRP, CNP, GRP, and ODN. This peptidomics project has also led to the discovery of several novel neuroendocrine peptides that were first isolated from frog brain tissue but have subsequently been identified in mammals. In particular, we have characterized (1) the somatostatin-14 (S-14) isoform [Pro2, Met13]S-14 as well as authentic S-14, thereby providing the first evidence for the occurrence of two somatostatin variants in the brain of a single species, (2) the first tetrapod urotensin II, a peptide that had long been thought to be produced only in the caudal neurosecretory system of fish, (3) secretoneurin, a peptide derived from the post-translational processing of secretogranin II, and (4) 26RFa, a novel member of the Arg-Phe-NH2 family of biologically active peptides. Orthologs of all these frog neuropeptides have now been identified in man and have been shown to exert important regulatory effects in mammals.
Supported by grants from INSERM (U413), the European Institute for Peptide Research (IFRMP23), the Platform for Cell Imaging of Haute-Normandie (PFRRICHN), the Conseil Régional de Haute-Normandie and the Laboratoire International Associé Samuel de Champlain.