Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuropeptide Y (NPY) and peptide YY (PYY) are homologous 36 amino acid amidated peptides that often, but not always, exert similar actions and binding profiles. The present study of cultured cells confirms that both peptides as well as radioiodinated analogs, i.e. 125I-Bolton-Hunter-NPY (125I-BH-NPY) and 125I-peptide YY (125I-PYY), show high affinity to binding sites/receptors of the previously proposed Y1- and Y2-subtypes, selectively expressed by the human neuroblastoma cell lines, SK-N-MC and SK-N-BE(2), respectively. In contrast, bovine adrenal chromaffin cells did not bind 125I-PYY, while displaying high affinity 125I-BH-NPY sites, and may therefore represent a cell type expressing a recently proposed Y3-type of (NPY-preferring) receptors. Several non-labeled fragments/analogs have been used in displacement experiments to further characterize the structural requirements for Y1-, Y2-, and Y3-type binding. In every instance, specific binding was reduced by addition of 5'-guanylylimidodiphosphate [Gpp(NH)p], indicating that the three receptor subtypes belong to the G-protein-coupled superfamily of receptors. Moreover, in both neuroblastoma cell lines, the peptides elicited, with appropriate orders of potency, reduction of forskolin-stimulated adenosine 3',5'-cyclic monophosphate (cAMP) accumulation. Finally, NPY-evoked 45Ca2+ influx was observed in SK-N-MC and in chromaffin cells. A common dual coupling mechanism of NPY/PYY receptors, i.e. to reduction of cAMP and to Ca2+ elevation, is therefore suggested to exist, although both phenomena could not be demonstrated in every cell type.
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PMID:Identification of cultured cells selectively expressing Y1-, Y2-, or Y3-type receptors for neuropeptide Y/peptide YY. 131 Jan 31

Neuropeptide Y (NPY) and peptide YY (PYY) are structurally related peptides that primarily function as neurotransmitter and gastrointestinal hormone, respectively. Previous functional and binding data have indicated the existence of at least three distinct receptor types, Y1, Y2, and Y3, for NPY and/or PYY in mammals. We describe here a human Y1 cDNA clone, hY1-5, isolated from a fetal brain library. The human Y1 receptor consists of 384 amino acids and has seven putative transmembrane domains like other members of the G-protein-coupled superfamily of receptors. In the region spanning the transmembrane domains, the Y1 receptor displays 29% sequence identity to human tachykinin receptors, but it only shows 21% and 23% homology with proposed bovine (LCR1) and Drosophila (PR4) NPY receptor clones, respectively. Northern blot analysis of a human neuroblastoma cell line, SK-N-MC, previously used by many investigators as a model system for studies on the Y1 receptor, revealed a single 3.5-kilobase mRNA species. Reverse transcriptase-polymerase chain reaction analysis indicated expression also in human cultured vascular smooth muscle cells, supporting the view that the Y1 receptor is associated with NPY/PYY-evoked vasoconstriction. When expressed in COS1 cells, hY1-5 conferred specific 125I-PYY binding sites with displacement patterns characteristic of the Y1 receptor, i.e. PYY greater than or equal to NPY greater than or equal to [Leu31,Pro34]NPY much greater than NPY2-36 greater than C2NPY greater than pancreatic polypeptide greater than NPY13-36 greater than NPY18-36. Moreover, in the Y1 receptor-transfected COS1 cells, but not in type 1 angiotensin II receptor-transfected control cells, NPY and PYY accelerated 45Ca2+ influx and inhibited forskolin-stimulated cAMP accumulation, both phenomena being characteristic of the mammalian Y1 receptor.
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PMID:Cloning and functional expression of a human neuropeptide Y/peptide YY receptor of the Y1 type. 131 48

Pharmacological studies indicate that peptide YY (PYY) and neuropeptide Y interact with multiple binding sites, categorized as Y1 and Y2 subtypes. In order to identify and structurally characterize the Y1 and Y2 receptors we covalently cross-linked [125I-Tyr36]PYY to its receptors. The Y2 receptor in rat hippocampus and rabbit kidney membranes was affinity labeled using different homo- and heterobifunctional cross-linking reagents. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography resulted in a major labeled protein band of Mr = 50,000 in both hippocampal and kidney membranes, which was unaffected by reducing agents. The Y1 receptor was analyzed in membranes from the MC-IXC human neuroblastoma cell line. Autoradiography revealed two labeled bands at Mr = 70,000 and 45,000. As the intensity of the Mr = 45,000 band was reduced by protease inhibitors, it is likely that this band is a degradation product of the larger band. Labeling of these proteins was obtained only when N-5-azido-2-nitrobenzoyloxysuccinimide was employed for cross-linking followed by exposure to UV light. Labeling of the two cross-linked bands was unaffected by reducing agents. The binding of radiolabeled PYY and the intensity of the cross-linked bands, for both the Y1 and Y2 receptors, were inhibited similarly in a dose-dependent manner by increasing concentrations of unlabeled PYY. When exposed to agarose-coupled lectins, the detergent-solubilized Y1 receptor-hormone complex was completely adsorbed by wheat germ agglutinin and partially by ricin communis II. The cross-linked Y2 receptor was almost totally adsorbed by wheat germ agglutinin-agarose and partially adsorbed by concanavalin A. The adsorptions were in all cases blocked by the appropriate hapten sugar. These results indicate that the Y1 receptor is a glycoprotein with a Mr = 70,000 binding subunit, whereas the Y2 receptor is a glycoprotein with a Mr = 50,000 binding subunit. These results provide evidence that the Y1 and Y2 subtypes of neuropeptide Y and PYY receptors, previously characterized pharmacologically, are structurally distinct glycoproteins, not disulfide-linked to other subunits.
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PMID:Structural characterization of Y1 and Y2 receptors for neuropeptide Y and peptide YY by affinity cross-linking. 215 75

We identified receptors for neuropeptide Y (NPY) on an established human neuroblastoma cell line, SK-N-MC, which are functionally coupled to adenylate cyclase through the inhibitory guanine nucleotide-binding protein of adenylate cyclase, Gi. Intact SK-N-MC cells bound radiolabeled NPY with a KD of 2 nM and contained approximately 83,000 receptors/cell. Unlabeled porcine and human NPY and structurally related porcine peptide YY (PYY) competed with labeled NPY for binding to the receptors. NPY inhibited cyclic AMP accumulation in SK-N-MC cells stimulated by isoproterenol, dopamine, vasoactive intestinal peptide, cholera toxin, and forskolin. NPY inhibited isoproterenol-stimulated cyclic AMP production in a dose-dependent manner, with half-maximal inhibition at 0.5 nM NPY. Porcine and human NPY and porcine PYY gave similar dose-response curves. NPY also inhibited basal and isoproterenol-stimulated adenylate cyclase activity in disrupted cells. Pertussis toxin treatment of the cells completely blocked the ability of NPY to inhibit cyclic AMP production and adenylate cyclase activity. The toxin catalyzed the ADP-ribosylation of a 41-kDa protein in SK-N-MC cells that corresponds to Gi. The receptors on SK-N-MC cells appeared to be specific for NPY, as other neurotransmitter drugs, such as alpha-adrenergic, dopaminergic, muscarinic, and serotonergic antagonists, did not compete for either NPY binding or NPY inhibition of adenylate cyclase. Thus, SK-N-MC cells may be a useful model for investigating NPY receptors and NPY-mediated signal transduction.
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PMID:Characterization of functional neuropeptide Y receptors in a human neuroblastoma cell line. 216 71

By using monoiodinated radioligands of both intact neuropeptide Y (NPY) and of a long C-terminal fragment, NPY13-36, two subtypes of binding sites, which differ in affinity and specificity, have been characterized. The Y1 type of binding site, characterized on a human neuroblastoma cell line, MC-IXC, and a rat pheochromocytoma cell line, PC-12, binds NPY with a dissociation constant (Kd) of a few nanomolar but does not bind NPY13-36. The Y2 type of binding site, characterized on porcine hippocampal membranes and on another human neuroblastoma cell line, SMS-MSN, is of higher affinity and binds both NPY and NPY13-36. None of the binding sites distinguish between NPY and the homologous peptide YY (PYY). It is concluded that NPY/PYY-binding sites occur in two subtypes which may represent two types of physiological receptors.
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PMID:Y1 and Y2 receptors for neuropeptide Y. 253 60

Monoiodinated radioligands of the homologous 36-amino acid peptides, neuropeptide Y (NPY) and peptide YY, were prepared by reverse phase high performance liquid chromatography with isocratic elution. [125I-Tyr1]- and [125I-Tyr36]monoiodoNPY bound equally well to a single class of high affinity binding sites on synaptosomal membranes prepared from porcine hippocampus (Kd = 1.0 X 10(-10) M) whereas iodine substitution in Tyr27, for example, partly interfered with the receptor binding. The receptors on the hippocampal membranes did not distinguish between neuropeptide Y and peptide YY either in their monoiodinated or in their unlabeled forms. Six out of twelve human neuroblastoma cell lines had high affinity binding sites for monoiodinated NPY ranging from 2 to 145 X 10(3) sites per cell. The NPY binding to three of the cell lines, SMS-MSN, SMS-KAN, and CHP-234 was of relatively high affinity (Kd = 1.3 to 6.1 X 10(-10) M), and, as in the hippocampal membranes, the long C-terminal fragment, NPY(13-36)peptide was also a relatively potent ligand for these receptors. Two other neuroblastoma cell lines, MC-IXC and CHP-212, expressed NPY receptors characterized by a lower affinity (Kd = 4.8 and 24.6 X 10(-9) M) and negligible cross-reactivity with the C-terminal fragment. It is concluded that monoiodinated radioligands of the tyrosine-rich neuropeptide Y can be prepared and that receptors for these ligands in two apparently different subtypes are found on a series of human neuroblastoma cell lines.
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PMID:Binding of monoiodinated neuropeptide Y to hippocampal membranes and human neuroblastoma cell lines. 270 30

Using guanine nucleotides, pertussis toxin, and specific antisera against the COOH-terminals of the alpha-subunits of Gi1/2, Gi3, and G(o), the binding and biological response of the Y2 receptor (Y2R) for peptide YY (PYY) was probed in SMS-KAN neuroblastoma cells. The specific binding of radiolabeled PYY exhibited a single apparent dissociation constant, KD = 76 pM for intact cells and KD = 906 pM for permeabilized cells. However, other data suggested existence of multiple receptor affinity states. A shift in KD and a decrease in apparent number of binding sites (Bmax) was observed in permeabilized cells when incubated with guanine nucleotides. By contrast, in membrane preparations guanine nucleotides induced only a decrease in Bmax. In intact cells, agonist exposure inhibited the intracellular accumulation of forskolin-stimulated cyclic AMP by 80% (IC50 = 420 nM) compared with 94% inhibition (IC50 = 380 nM) in permeabilized cells. In permeabilized cells, preincubation with antisera against alpha i1/2 and alpha i3 blocked the functional response of PYY, with anti-alpha i3 being the most potent; whereas anti-alpha o failed to affect the cyclic AMP levels. These results suggest that permeabilized SMS-KAN cells serve as a good model system for analysis of Y2R binding kinetics and functional response and that the Y2R interacts directly with several different GiS (but not G(o)).
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PMID:Coupling of the human Y2 receptor for neuropeptide Y and peptide YY to guanine nucleotide inhibitory proteins in permeabilized SMS-KAN cells. 783 57

We have investigated binding and functional effects of a new peptide YY analogue, [Pro34]peptide YY, at Y1 and Y2-like subtypes of receptors for peptide YY and neuropeptide Y. In binding studies [Pro34]peptide YY had a similarly high affinity as peptide YY to human Y1-like receptors in SK-N-MC cells, a human neuroblastoma cell line of presumed neurogenic origin, and HEL cells, a human cell line derived from a patient with Hodgkin's disease. In functional studies [Pro34]peptide YY stimulated Ca2+ elevations in both Y1-like receptor cell lines with similar potency and efficacy as peptide YY. In contrast to peptide YY [Pro34]peptide YY was 1000-fold less potent in binding to Y2-like receptors in porcine splenic membranes and lacked agonistic effects in another Y2-like receptor-mediated model system, i.e. inhibition of [3H]serotonin release from rat cerebral cortical slices. Thus, [Pro34]peptide YY is a highly Y1-selective full agonist of peptide YY/neuropeptide Y receptors. [Pro34]peptide YY could be useful for studying the importance of Y receptor subtypes in mediating peptide YY physiological actions.
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PMID:[Pro34]peptide YY is a Y1-selective agonist at peptide YY/neuropeptide Y receptors. 785 89

The modulation of neuropeptide Y (NPY) and peptide YY (PYY) receptors by dynorphin, luteinizing hormone-releasing hormone (LHRH), corticotropin-releasing factor (CRF), and cholecystokinin octapeptide has been studied in human neuroblastoma cell lines SK-N-MC and SMS-MSN, which express Y1 and Y2 receptors for NPY/PYY. Dynorphin A and LHRH inhibited the binding of NPY/PYY to SK-N-MC cell membranes at concentrations ranging from 10(-7) to 10(-5) M, whereas dynorphin A and CRF were effective in SMS-MSN cells. The inhibitory effect of dynorphin A on NPY/PYY binding was observed in the presence of guanosine 5'-O-(3-thiotriphosphate), a nonhydrolyzable GTP analogue, as well as H-7 and H-8, novel inhibitors of protein kinases C and A. However, U-50488, the most potent kappa-selective compound did not mimic the dynorphin action. Dynorphin A showed neither effect on the dissociation of NPY/PYY from their receptors nor inhibition on the basal as well as forskolin-stimulated adenosine 3',5'-cyclic monophosphate response. These results indicate that the interaction of dynorphin A with Y1 and Y2 receptors is not mediated by changes in receptor-G protein interaction, receptor phosphorylation, and allosteric binding to NPY/PYY receptors but that dynorphin A binds to NPY/PYY receptors at high concentrations, probably in an antagonistic manner.
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PMID:Dynorphin binds to neuropeptide Y and peptide YY receptors in human neuroblastoma cell lines. 797 21

We have carried out functional and in vitro studies on a novel analog of neuropeptide Y which shows selectivity for the prejunctional or neuropeptide Y Y2 receptor. In anaesthetised rats N-acetyl [Leu28,Leu31]neuropeptide Y-(24-36) attenuates cardiac vagal action (a prejunctional or neuropeptide Y Y2 action) and has no significant pressor effects (postjunctional or neuropeptide Y Y1 action). In the human neuroblastoma cell line (SMS-KAN) which expresses and endogenous Y2-like neuropeptide Y receptor, N-acetyl [Leu28,Leu31]neuropeptide Y-(24-36) competes with peptide YY for binding sites with an IC50 of 0.5 +/- 0.1 nM. In contrast in a fibroblast Chinese hamster ovary cell line which expresses the cloned human neuropeptide Y Y1 receptor and is used to study changes in cytosolic calcium evoked by (a neuropeptide Y Y1 effect), N-acetyl [Leu28,Leu31]neuropeptide Y-(24-36) showed no activity even at high concentrations. The steric structure for this novel compound has been determined using proton nuclear magnetic resonance (NMR) spectroscopy and it is consistent with the C-terminal end of published structures of neuropeptide Y. We suggest acetylation and amino acid substitutions stabilise the molecule and allow it to bind only to the neuropeptide Y Y2 receptor.
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PMID:A novel neuropeptide Y analog, N-acetyl [Leu28,Leu31]neuropeptide Y-(24-36), with functional specificity for the presynaptic (Y2) receptor. 808 64


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