Primary structure of frog PYY: implications for the molecular evolution of the pancreatic polypeptide family.
ABSTRACT A peptide belonging to the pancreatic polypeptide (PP) family was isolated in pure form from the intestine of the European green frog (Rana ridibunda). The primary structure of the peptide was established as: Tyr-Pro-Pro-Lys-Pro-Glu-Asn-Pro-Gly-Glu10-Asp-Ala- Ser-Pro-Glu-Glu-Met-Thr-Lys-Tyr20-Leu-Thr-Ala-Leu-Arg-His-Tyr-Ile- Asn-Leu30-Val - Thr-Arg-Gln-Arg-Tyr-NH2. This amino acid sequence shows moderate structural similarity to human PYY (75% identity) but stronger similarity to the PP family peptides isolated from the pancreas of the salmon (86%) and dogfish (83%). The data suggest that the two putative duplications of an ancestral PP family gene that have given rise to PP, PYY and NPY in mammals had already taken place by the time of the appearance of the amphibia. In fish, however, only a single duplication has occurred, giving rise to NPY in nervous tissue and a PYY-related peptide in both pancreas and gut.
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ABSTRACT: The endocrine cells of the starfish digestive tract are spindle-shaped, contacting both the lumen and the basiepithelial plexus. Silver impregnation labels the basiepithelial and subcoelomic plexuses as well as these cells. Twenty antisera have been tested using the avidinbiotin method, in order to identify the regulatory substances involved in this system. Endocrine cells and nerves immunoreactive to GFNSALMFamide- (S1), FMRFamide-, peptide tyrosine-tyrosine-(PYY), pancreatic polypeptide- (PP), melanocyte stimulating hormone- (MSH) and peptidylglycine alpha-amidating monooxygenase- (PAM) specific antisera have been found in the epithelium. The antibodies against S1, a peptide isolated from the nervous system of a starfish, and MSH, stain both the basiepithelial plexus and the subcoelomic plexus, but the others react only with nerves in the basiepithelial plexus. Absorption controls show that antibodies for S1 and FMRFamide totally crossreact recognizing the same molecule, possibly S1. The other antibodies do not show cross-reactivity to any of the rest, and thus we conclude that these regulatory peptides are present in starfish. This is the first report of the presence of FMRFamide, PYY, MSH and PAM in the Echinodermata. Under the electron microscope the endocrine cells exhibit secretory granules, microtubules and mitochondria. Direct contact with the subcoelomic plexus can be observed.Cell and Tissue Research 01/1993; 271(2):375-380. · 3.33 Impact Factor
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ABSTRACT: Endocrine cells exhibiting immunoreactivity to FMRFamide-like, LPLRFamide-like, neuropeptide Y(NPY)-like and peptide YY(PYY)-like peptides were found in the periphery of the Brockmann bodies of the cod, Gadus morhua, and rainbow trout, Oncorhynchus mykiss. No immunoreactivity or very weak labelling was found with antisera to pancreatic polypeptide (PP). Vasoactive intestinal polypeptide (VIP)-like immunoreactivity was found in nerve fibres, whereas labelling with VIP antiserum in endocrine cells disappeared after preincubation with nonimmune serum. There were always more immunoreactive cells in the rainbow trout than in the cod. No immunoreactivity could be seen with antisera to gastrin/cholecystokinin (CCK) or enkephalin. Double-labelling studies were performed to study the colocalization of the peptides in peripheral endocrine cells. Cells immunoreactive to NPY were also labelled with antisera to FMRFamide, LPLRFamide and PYY. The co-localization pattern of NPY varied; in some Brockmann bodies, a population of the immunoreactive cells showed co-localization and others contained NPY-like immunoreactivity only, whereas in other Brockmann bodies, all NPY-labelled cells also contained FMRFamide-like, LPLRFamide-like and PYY-like immunoreactivity. Cells immunoreactive to PYY similarly contained FMRFamide-like, LPLRFamide-like and NPY-like immunoreactivity, comparable to the patterns observed with NPY. Glucagon-like immunoreactivity was found at the periphery of the Brockmann bodies. A subpopulation of the glucagon-containing cells contained NPY-like immunoreactivity. PYY-like immunoreactivity was also found co-localized with glucagon-like immunoreactivity, as were FMRFamide-like and LPLRFamide-like immunoreactivity. Therefore, either NPY-like and PYY-like immunoreactivity together with FMRFamide-like and LPLRFamide-like immunoreactivity occur in the same endocrine cells of the Brockmann body of the cod and rainbow trout, or a hybrid NPY/PYY-like peptide recognized by both NPY and PYY antisera is present in the Brockmann body.Cell and Tissue Research 08/1993; 273(3):547-555. · 3.33 Impact Factor
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ABSTRACT: The distribution ofproneuropeptide Y-containing perikarya and nerve fibers in the brain of Rana esculenta and Xenopus lavis was determined with antisera directed toward neuropeptide Y and the carboxyl terminal flanking peptide.The distribution of proneuropeptide Y-like immunoreactivity was similar in both anurans. In the telencephalon, immunoreactive perikarya were found in the olfactory bulb, all subdivisions of the pallium, the septum, pars lateralis of the amygdala, the nucleus accumbens, and the anterior preoptic area. In the diencephalon, labelled perikarya were detected in the ventromedial, ventrolateral and central thalamic nuclei, the magnocellular preoptic nucleus, the suprachiasmatic nucleus, the posterior tuberculum, and the infundibulum. Amacrine-like cells were stained in the retina. In the pretectal area, posterior thalamic neurons showed intense, Golgi-like immunostaining. In the mesencephalon, immunoreactive cells were found in the reticular nucleus, the anteroventral tegmental nucleus, the optic tectum, the interpeduncular nucleus, and the torus semicircularis. In the rhombencephalon, labelled perikarya were detected in the secondary visceral nucleus, the central gray, the nucleus of the solitary tract, the dorsal column nuclei, and the spinal nucleus of the trigeminal nerve.Immunoreactive nerve fibers were observed in all areas of the brain that contained labelled perikarya. The densest accumulations were found in the accessory olfactory bulb, pars lateralis of the amygdala, the ventral habenula, the posterior pituitary, the optic tectum, the interpeduncular nucleus, and the saccular nucleus.The distribution of proneuropeptide Y-like immunoreactivity in the anuran brain showed many similarities to the distribution described for the amniote brain. © 1993 Wiley-Liss, Inc.The Journal of Comparative Neurology 01/1993; 327(4):551 - 571. · 3.51 Impact Factor