Strong evolutionary conservation of neuropeptide Y: sequences of chicken, goldfish, and Torpedo marmorata DNA clones.

Abstract

Neuropeptide Y (NPY) is an abundant and widespread neuropeptide in the nervous system of mammals. NPY belongs to a family of 36-amino acid peptides that also includes pancreatic polypeptide and the endocrine gut peptide YY as well as the fish pancreatic peptide Y. To study the evolution of this peptide family, we have isolated clones encoding NPY from central nervous system cDNA libraries of chicken, goldfish, and the ray Torpedo marmorata, as well as from a chicken genomic library. The predicted chicken NPY amino acid sequence differs from that of rat at only one position. The goldfish sequence differs at five positions and shows that bony fishes have a true NPY peptide in addition to their pancreatic peptide Y. The Torpedo sequence differs from that of rat at three positions. As Torpedo NPY has no unique positions when compared with the other sequences, it seems to be identical to the NPY of the common ancestor ofcartilaginous fishes, bony fishes, and tetrapods after 420 million years of evolution. The 30-amino acid carboxyl-terminal extension of the NPY precursor also displays considerable sequence conservation. These results show that NPY is one ofthe most highly conserved neuroendocrine peptides.Neuropeptide Y (NPY) was first purified from porcine brain (1). The name is derived from its amino-and carboxylterminal tyrosines (single-letter code Y). Subsequently, NPY sequences have been determined for six other mammals (2) and for a frog (3), revealing a remarkable degree of conservation. NPY occurs abundantly in the mammalian central nervous system as well as in the peripheral nervous system (4) and has been shown to have both pre-and postsynaptic actions (5).NPY belongs to a family of peptides that includes the gut endocrine peptide YY (PYY) and the pancreatic endocrine peptides called pancreatic polypeptide (PP) in tetrapods and peptide tyrosine (PY) in fish. All of these peptides consist of 36 amino acids and have a carboxyl-terminal amide. Porcine NPY and PYY show 70% sequence identity and can act on the same receptors with similar potencies (6), whereas porcine PP is only 50% identical to NPY and PYY and appears to have distinct receptors (7-9). PP differs considerably between species; PP of pig, chicken, and bullfrog share only 44-58% identity.Pancreatic peptides have been isolated and sequenced from four different species of fish (2). Surprisingly, these peptides were found to be more similar to mammalian NPY and PYY than to PP. Because of the unclear relationships with the mammalian peptides, the fish pancreatic peptides have been given different names by different groups of investigators. We use here the designation PY.Immunohistochemical studies of NPY, PYY, and PP have been interpreted to indicate that PP appeared first in evolution (10), and sequence and receptor-binding analyses have suggested that PP forms one evolutionary lineage whereas NPY and PYY form a separate lineage and diverged from each other more recently (11). To extend the structural evolutionary analyses, we decided to isol...

Terminal Nerve-Derived Neuropeptide Y Modulates Physiological Responses in the Olfactory Epithelium of Hungry Axolotls (Ambystoma mexicanum)

“…Compared with other amphibian sequences, the predicted axolotl NPY sequence displays variation in positions 6 and 7. Although the substitution of Asn for Ser at position 7 has been observed previously in the chicken (Blomqvist et al, 1992), replacement of Asp for Asn at position 6 is unique among reported tetrapod NPY sequences. Within previously known tetrapod NPYs, only four positions have been shown to vary (positions 7, 10, 17, and 19), and 32 positions, particularly those toward the C terminus, remain perfectly conserved (Larhammar, 1996;Cerda-Reverter and Larhammar, 2000).…”

Expression of Neuropeptide Y of GIFT Tilapia (Oreochromis sp.) in Yeast Pichia Pastoris and Its Stimulatory Effects on Food Intake and Growth

“…Sequence alignment of amino acids showed that the NPY mature peptide of GIFT tilapia is the identity of that red tilapia (GenBank: AAV49168) and highly homologous to human NPY with the identity of 86%. This result again clearly proved that NPY is the most highly conserved neuropeptide in vertebrates (Blomqvist et al, 1992). In the study of protein function, E. coli is commonly used to express large quantities of protein.…”

“…NPY executes these functions mainly through its receptor Y1, Y2 and Y5 (Aldegunde and Mancebo, 2006;Pedrazzini et al, 2003). NPY is one of the most highly conserved neuroendocrine peptides in vertebrates (Blomqvist et al, 1992). The NPY peptides of fish species also showed remarkable sequence homology with mammals, suggesting the similar functions of NPY in fish and mammals (CerdaReverter et al, 2000b;Sundstrom et al, 2005).As its mammalian counterpart, NPY is also a very important regulator of food intake and energy metabolism in fish (Volkoff, 2006;Volkoff et al, 2005).…”

The primary structure of a PYY‐related peptide from chicken intestine suggests an anomalous site of cleavage of the signal peptide in preproPYY

“…This study has described the first isolation and structural characterization of a PYY-related peptide from a bird, chicken, and complements earlier studies describing the characterization of chicken PP [10] and the cloning and nucleotide sequence analysis of the eDNA encoding chicken NPY [11]. As shown in Table I, evolutionary pressure to conserve the amino acid sequence of the chicken PP-family peptides has been weak, with only 13 invariant residues between the three molecules.…”