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Neuropeptide Y‐family receptors Y 6 and Y 7 in chicken
Author(s) -
Bromée Torun,
Sjödin Paula,
Fredriksson Robert,
Boswell Tim,
Larsson Tomas A.,
Salaneck Erik,
Zoorob Rima,
Mohell Nina,
Larhammar Dan
Publication year - 2006
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2006.05221.x
Subject(s) - neuropeptide y receptor , biology , receptor , microbiology and biotechnology , peptide yy , synteny , amino acid , adipose tissue , gene , neuropeptide , chromosome , endocrinology , genetics
The peptides of the neuropeptide Y (NPY) family exert their functions, including regulation of appetite and circadian rhythm, by binding to G‐protein coupled receptors. Mammals have five subtypes, named Y 1 , Y 2 , Y 4 , Y 5 and Y 6 , and recently Y 7 has been discovered in fish and amphibians. In chicken we have previously characterized the first four subtypes and here we describe Y 6 and Y 7 . The genes for Y 6 and Y 7 are located 1 megabase apart on chromosome 13, which displays conserved synteny with human chromosome 5 that harbours the Y 6 gene. The porcine PYY radioligand bound the chicken Y 6 receptor with a K d of 0.80 ± 0.36 n m . No functional coupling was demonstrated. The Y 6 mRNA is expressed in hypothalamus, gastrointestinal tract and adipose tissue. Porcine PYY bound chicken Y 7 with a K d of 0.14 ± 0.01 n m (mean ± SEM), whereas chicken PYY surprisingly had a much lower affinity, with a K i of 41 n m , perhaps as a result of its additional amino acid at the N terminus. Truncated peptide fragments had greatly reduced affinity for Y 7 , in agreement with its closest relative, Y 2 , in chicken and fish, but in contrast to Y 2 in mammals. This suggests that in mammals Y 2 has only recently acquired the ability to bind truncated PYY. Chicken Y 7 has a much more restricted tissue distribution than other subtypes and was only detected in adrenal gland. Y 7 seems to have been lost in mammals. The physiological roles of Y 6 and Y 7 remain to be identified, but our phylogenetic and chromosomal analyses support the ancient origin of these Y receptor genes by chromosome duplications in an early (pregnathostome) vertebrate ancestor.