title: Neuropeptide Y/peptide YY receptor Y2 duplicate in zebrafish with unique introns displays distinct peptide binding properties.
abstract: The neuropeptide Y-family peptides and receptors are involved in a broad range of functions including appetite regulation. Both the peptide genes and the receptor genes are known to have duplicated in early vertebrate evolution. The ancestral jawed vertebrate had 7 NPY receptors but the number varies between 4 and 7 in extant vertebrates. Herein we describe the identification of an additional NPY receptor in two fish species, zebrafish and medaka. They cluster together with the Y2 receptors in phylogenetic analyses and seem to be orthologous to each other that is why we have named them Y2-2. Their genes differ from Y2 in having introns in the coding region. Binding studies with zebrafish Y2-2 receptors show that the three endogenous peptides NPY, PYYa and PYYb have similar affinities, 0.15-0.66 nM. This is in contrast to the Y2 receptor where they differed considerably from one another. N-terminally truncated NPY binds poorly and the Y2 antagonist BIIE0246 binds well to Y2-2, results that are reversed in comparison to Y2. Zebrafish Y2-2 mRNA was detected by PCR in the intestine and the eye, but not in the brain. In conclusion, we have found a novel Y2-like NPY/PYY receptor that probably arose in early teleost fish evolution.
authors.affiliation: Department of Neuroscience, Uppsala University, Sweden.
authors.forename: Helena
authors.initials: H
authors.lastname: Fällmar
authors.forename: Görel
authors.initials: G
authors.lastname: Sundström
authors.forename: Ingrid
authors.initials: I
authors.lastname: Lundell
authors.forename: Nina
authors.initials: N
authors.lastname: Mohell
authors.forename: Dan
authors.initials: D
authors.lastname: Larhammar
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D005075:Biological Evolution; D018929:Cell Culture Techniques; D020440:Gene Duplication / Q000235:genetics*; D057809:HEK293 Cells / Q000378:metabolism; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000737:chemistry / Q000378:metabolism; D009990:Oryzias; D019894:Peptide YY / Q000737:chemistry / Q000378:metabolism; D011964:Receptors, Gastrointestinal Hormone / Q000737:chemistry / Q000378:metabolism*; D017476:Receptors, Neuropeptide Y / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D015027:Zebrafish / Q000378:metabolism*
chemical_list: D009478:Neuropeptide Y; D011964:Receptors, Gastrointestinal Hormone; D017476:Receptors, Neuropeptide Y; C095889:neuropeptide Y2 receptor; C082172:peptide YY receptor; D019894:Peptide YY