title: Characterization of NPY receptor subtypes Y2 and Y7 in rainbow trout Oncorhynchus mykiss.
abstract: We report the cloning and pharmacological characterization of two neuropeptide Y (NPY) receptor subtypes, Y2 and Y7, in rainbow trout (Oncorhynchus mykiss). These subtypes are approximately 50% identical to each other and belong to the Y2 subfamily of NPY receptors. The binding properties of the receptors were investigated after expression in human HEK-293 EBNA cells. Both receptors bound the three zebrafish peptides NPY, PYYa, and PYYb, as well as porcine NPY and PYY, with affinities in the nanomolar range that are similar to mammalian Y2. The affinity of the truncated porcine NPY fragments, NPY 13-36 and NPY 18-36 was markedly lower compared to mammalian and chicken Y2. This suggests that mammalian and chicken Y2 are unique among NPY receptors in their ability to bind truncated peptide fragments. The antagonist BIIE0246, developed for mammalian Y2, did not bind either of the two rainbow trout receptors. Our results support the proposed expansion of this gene family by duplications before the gnathostome radiation. They also reveal appreciable differences in the repertoire and characteristics of NPY receptors between fish and tetrapods stressing the importance of lineage-specific gene loss as well as sequence divergence after duplication.
authors.affiliation: Department of Neuroscience, Uppsala University, Box 593, SE-75124, Uppsala, Sweden. tomas.larsson@neuro.uu.se
authors.forename: Tomas A
authors.initials: TA
authors.lastname: Larsson
authors.forename: Earl T
authors.initials: ET
authors.lastname: Larson
authors.forename: Robert
authors.initials: R
authors.lastname: Fredriksson
authors.forename: J Michael
authors.initials: JM
authors.lastname: Conlon
authors.forename: Dan
authors.initials: D
authors.lastname: Larhammar
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D015723:Gene Library; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000737:chemistry; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D017476:Receptors, Neuropeptide Y / Q000737:chemistry* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D009478:Neuropeptide Y; D017476:Receptors, Neuropeptide Y; C095889:neuropeptide Y2 receptor