title: Identification of the endogenous cysteine-rich peptide trissin, a ligand for an orphan G protein-coupled receptor in Drosophila.
abstract: There are many orphan G protein-coupled receptors (GPCRs), for which ligands have not yet been identified, in both vertebrates and invertebrates, such as Drosophila melanogaster. Identification of their cognate ligands is critical for understanding the function and regulation of such GPCRs. Indeed, the discovery of bioactive peptides that bind GPCRs has enhanced our understanding of mechanisms underlying many physiological processes. Here, we identified an endogenous ligand of the Drosophila orphan GPCR, CG34381. The purified ligand is a peptide comprised of 28 amino acids with three intrachain disulfide bonds. The preprotein is coded for by gene CG14871. We designated the cysteine-rich peptide "trissin" (it means for triple S-S bonds) and characterized the structure of intrachain disulfide bonds formation in a synthetic trissin peptide. Because the expression of trissin and its receptor is reported to predominantly localize to the brain and thoracicoabdominal ganglion, trissin is expected to behave as a neuropeptide. The discovery of trissin provides an important lead to aid our understanding of cysteine-rich peptides and their functional interaction with GPCRs.
authors.affiliation: Interdisciplinary Research Organization, University of Miyazaki, Miyazaki 889-1692, Japan. a0d203u@cc.miyazaki-u.ac.jp
authors.forename: Takanori
authors.initials: T
authors.lastname: Ida
authors.forename: Tomoko
authors.initials: T
authors.lastname: Takahashi
authors.forename: Hatsumi
authors.initials: H
authors.lastname: Tominaga
authors.forename: Takahiro
authors.initials: T
authors.lastname: Sato
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kume
authors.forename: Kumiko
authors.initials: K
authors.lastname: Yoshizawa-Kumagaye
authors.forename: Hideki
authors.initials: H
authors.lastname: Nishio
authors.forename: Johji
authors.initials: J
authors.lastname: Kato
authors.forename: Noboru
authors.initials: N
authors.lastname: Murakami
authors.forename: Mikiya
authors.initials: M
authors.lastname: Miyazato
authors.forename: Kenji
authors.initials: K
authors.lastname: Kangawa
authors.forename: Masayasu
authors.initials: M
authors.lastname: Kojima
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003545:Cysteine / Q000737:chemistry; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D008969:Molecular Sequence Data; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D029721:Drosophila Proteins; D008024:Ligands; D043562:Receptors, G-Protein-Coupled; C568475:Trissin protein, Drosophila; C568474:TrissinR protein, Drosophila; D003545:Cysteine