Isolation, Pharmacology and Gene Organization of KPSFVRFamide: A Neuropeptide fromCaenorhabditis elegans

• Published in: Biochemical and biophysical research communications Vol. 254; no. 1; pp. 222 - 230
• Main Authors: Marks, N.J., Maule, A.G., Li, C., Nelson, L.S., Thompson, D.P., Alexander-Bowman, S., Geary, T.G., Halton, D.W., Verhaert, P., Shaw, C.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 08.01.1999
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1998.9920

To date, 53 peptides with C-terminal RFamides have been identified by the genome sequencing project in the nematode,Caenorhabditis elegans.In this study the FMRFamide-related peptide (FaRP) KPSFVRFamide (879.90 Da [MH]+) was structurally characterized from extracts of the nematode,Caenorhabditis elegans.Two copies of KPSFVRFamide are encoded by a gene designatedflp-9. RT-PCR identified a single cDNA product which was confirmed asflp-9 by sequence determination.Flp-9 cDNA was isolated from larval stages ofC. elegansbut was not detected in adult worms, indicating that its expression is may be developmentally regulated. KPSFVRFamide displays sequence homology to the nematode peptide, KPNFIRFamide (PF4). The physiological effects of KPSFVRFamide, PF4 and the chimeras, KPNFVRFamide and KPSFIRFamide, were measured on body wall muscle and the vagina vera of the parasitic nematode,Ascaris suum.KPNFVRFamide and KPNFIRFamide had Cl−-dependent inhibitory activity on innervated and denervated muscle-preparations, whereas KPSFVRFamide and KPSFIRFamide did not elicit a detectable physiological effect. Although all 4 peptides had inhibitory effects on the vagina vera, KPSFVRFamide and KPSFIRFamide (threshold, ≥0.1 μM) were less potent than KPNFVRFamide and KPNFIRFamide (threshold, ≥10 nM).