title: Molecular identification of the long isoform of the human neuropeptide Y Y5 receptor and pharmacological comparison with the short Y5 receptor isoform.
abstract: The neuropeptide Y Y5 receptor gene generates two splice variants, referred to here as Y5(L) (long isoform) and Y5(S) (short isoform). Y5(L) mRNA differs from Y5(S) mRNA in its 5' end, generating a putative open reading frame with 30 additional nucleotides upstream of the initiator AUG compared with the Y5(S) mRNA. The purpose of the present work was to investigate the existence of the Y5(L) mRNA. The authenticity of this transcript was confirmed by isolating part of its 5' untranslated region through 5' rapid amplification of cDNA ends and analysing its tissue distribution. To study the initiation of translation on Y5(L) mRNA, we cloned the Y5(L) cDNA and two Y5(L) cDNA mutants lacking the first or the second putative initiation start codon. Transient expression of the three plasmids in COS-7 cells and saturation binding experiments using (125)I-labelled polypeptide YY (PYY) as a ligand showed that initiation of translation on Y5(L) mRNA could start at the first AUG, giving rise to a Y5(L) receptor with an N-terminal 10-amino-acid extension when compared with the Y5(S) receptor. The human Y5(L) and Y5(S) receptor isoforms displayed similar affinity constants (1.3 nM and 1.5 nM respectively). [(125)I]PYY binding to COS-7 cells expressing either the Y5(L) or the Y5(S) isoform was inhibited with the same rank order of potency by a selection of six chemically diverse compounds: PYY>neuropeptide Y>pancreatic polypeptide>CGP71683A>Synaptic 34>Banyu 6. Comparison of the tissue distribution of Y5(L) and Y5(S) mRNAs, as determined by reverse transcription-PCR analysis, indicated that expression of Y5(L) mRNA occurs in a tissue-specific manner. Finally, we have shown that the two AUG triplets contained in the 5' untranslated region of Y5(L) mRNA did not affect receptor expression.
authors.affiliation: Institut de Recherches Servier, Division de Pharmacologie Moléculaire et Cellulaire, 125 chemin de Ronde, 78 290 Croissy sur Seine, France.
authors.forename: Marianne
authors.initials: M
authors.lastname: Rodriguez
authors.forename: Valérie
authors.initials: V
authors.lastname: Audinot
authors.forename: Sandra
authors.initials: S
authors.lastname: Dromaint
authors.forename: Christelle
authors.initials: C
authors.lastname: Macia
authors.forename: Véronique
authors.initials: V
authors.lastname: Lamamy
authors.forename: Philippe
authors.initials: P
authors.lastname: Beauverger
authors.forename: Hervé
authors.initials: H
authors.lastname: Rique
authors.forename: Jérôme
authors.initials: J
authors.lastname: Imbert
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Nicolas
authors.forename: Jean A
authors.initials: JA
authors.lastname: Boutin
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Galizzi
mesh_terms: D020121:5' Untranslated Regions; D017398:Alternative Splicing; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D019556:COS Cells / Q000187:drug effects; D003001:Cloning, Molecular; D018387:Codon, Initiator; D006801:Humans; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000378:metabolism / Q000494:pharmacology; D014176:Protein Biosynthesis; D020033:Protein Isoforms / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D017476:Receptors, Neuropeptide Y / Q000037:antagonists & inhibitors / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D018911:Trinucleotide Repeats / Q000235:genetics
chemical_list: D020121:5' Untranslated Regions; C092926:BIBP 3226; D018387:Codon, Initiator; D009478:Neuropeptide Y; D020033:Protein Isoforms; D012333:RNA, Messenger; D017476:Receptors, Neuropeptide Y; C100568:neuropeptide Y5 receptor; D001120:Arginine; C117416:BIBO 3304