title: Structure and bioactivity of neuropeptide F from the human parasites Schistosoma mansoni and Schistosoma japonicum.
abstract: The blood flukes Schistosoma mansoni and Schistosoma japonicum inflict immense suffering as agents of human schistosomiasis. Previous investigations have found the nervous systems of these worms contain abundant immunoreactivity to antisera targeting invertebrate neuropeptide Fs (NPFs) as well as structurally similar neuropeptides of the mammalian neuropeptide Y (NPY) family. Here, cDNAs encoding NPF in these worms were identified, and the mature neuropeptides from the two species differed by only a single amino acid. Both neuropeptides feature the characteristics common among NPFs; they are 36 amino acids long with a carboxyl-terminal Gly-Arg-X-Arg-Phe-amide and Tyr residues at positions 10 and 17 from the carboxyl terminus. Synthetic S. mansoni NPF potently inhibits the forskolin-stimulated accumulation of cAMP in worm homogenates, with significant effects at 10(-11) m. This is the first demonstration of an endogenous inhibition of cAMP by an NPF, and because this is the predominant pathway associated with vertebrate NPY family peptides, it demonstrates a conservation of downstream signaling pathways used by NPFs and NPY peptides.
authors.affiliation: Department of Biomedical Sciences and Neuroscience Program, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Judith E
authors.initials: JE
authors.lastname: Humphries
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kimber
authors.forename: Yi-Wen
authors.initials: YW
authors.lastname: Barton
authors.forename: Walter
authors.initials: W
authors.lastname: Hsu
authors.forename: Nikki J
authors.initials: NJ
authors.lastname: Marks
authors.forename: Brett
authors.initials: B
authors.lastname: Greer
authors.forename: Pat
authors.initials: P
authors.lastname: Harriott
authors.forename: Aaron G
authors.initials: AG
authors.lastname: Maule
authors.forename: Tim A
authors.initials: TA
authors.lastname: Day
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018076:DNA, Complementary; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000235:genetics* / Q000378:metabolism*; D012549:Schistosoma japonicum / Q000235:genetics*; D012550:Schistosoma mansoni / Q000235:genetics*; D015398:Signal Transduction / Q000502:physiology
chemical_list: D018076:DNA, Complementary; D009479:Neuropeptides; C076101:neuropeptide F