title: Discovery by proteogenomics and characterization of an RF-amide neuropeptide from cone snail venom.
abstract: In this study, a proteogenomic annotation strategy was used to identify a novel bioactive peptide from the venom of the predatory marine snail Conus victoriae. The peptide, conorfamide-Vc1 (CNF-Vc1), defines a new gene family. The encoded mature peptide was unusual for conotoxins in that it was cysteine-free and, despite low overall sequence similarity, contained two short motifs common to known neuropeptides/hormones. One of these was the C-terminal RF-amide motif, commonly observed in neuropeptides from a range of organisms, including humans. The mature venom peptide was synthesized and characterized structurally and functionally. The peptide was bioactive upon injection into mice, and calcium imaging of mouse dorsal root ganglion (DRG) cells revealed that the peptide elicits an increase in intracellular calcium levels in a subset of DRG neurons. Unusually for most Conus venom peptides, it also elicited an increase in intracellular calcium levels in a subset of non-neuronal cells.
  
  
  CONCLUSIONS
  Our findings illustrate the utility of proteogenomics for the discovery of novel, functionally relevant genes and their products. CNF-Vc1 should be useful for understanding the physiological role of RF-amide peptides in the molluscan and mammalian nervous systems.
authors.affiliation: Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Australia. Electronic address: sam.robinson@monash.edu.
authors.forename: Samuel D
authors.initials: SD
authors.lastname: Robinson
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112, USA. Electronic address: safavihelena@gmail.com.
authors.forename: Helena
authors.initials: H
authors.lastname: Safavi-Hemami
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Shrinivasan
authors.initials: S
authors.lastname: Raghuraman
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Julita S
authors.initials: JS
authors.lastname: Imperial
authors.affiliation: Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia.
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Papenfuss
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Russell W
authors.initials: RW
authors.lastname: Teichert
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, VIC 3800, Australia.
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Purcell
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Baldomero M
authors.initials: BM
authors.lastname: Olivera
authors.affiliation: Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Australia.
authors.forename: Raymond S
authors.initials: RS
authors.lastname: Norton
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D020916:Conotoxins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D052078:Conus Snail / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D056726:Genetic Association Studies / Q000379:methods; D023281:Genomics; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D008978:Mollusk Venoms / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D009474:Neurons / Q000166:cytology / Q000187:drug effects; D009479:Neuropeptides / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D040901:Proteomics
chemical_list: D020916:Conotoxins; D008978:Mollusk Venoms; D009479:Neuropeptides; C449522:conorfamide
keywords: Calcium imaging; Conotoxin; Neuropeptide; Proteogenomics; RF-amide; Venom