Evidence for and Characterization of Specific High Affinity Binding Sites for the Gastric Inhibitory Polypeptide in Pancreatic<i>β</i>-Cells*

Maletti, M.; Portha, Bernard; Carlquist, Mats; Kergoat, Micheline; Laburthe, Marc; Marie, J; Rosselin, G

doi:10.1210/endo-115-4-1324

Cited by 38 publications

(16 citation statements)

References 29 publications

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“…1). We have previously shown that the iodination of VIP or GIP leads to a more hydrophobic compound than the native peptide [13,20]. This is in agreement with the observation that halides generally increase the hydrophobic nature of molecules [22].…”

Section: Preparation and Purification Of Iodinated Ss-28supporting

confidence: 85%

“…The animals were killed 60 days after the grafting and the enriched membrane fraction was prepared as described [13]. Briefly, the tumors were dissected, homogenized, using a Waring blender, in a freshly prepared 20 mM Hepes buffer (pH 7.5) containing 0.25 M sucrose, 0.01 M triethanolamine, 5 mM EDTA, 0.1 M phenylmethylsulfonyl fluoride and bacitracin (1 mg/ml) and centrifuged at 2000 x g for 20 min, after which the supernatant was centrifuged at 20000 x g for 20 min and the pellet resuspended and washed twice in 20mM Hepes buffer (pH 7.5).…”

Section: Preparation Of Pancreatic Membranesmentioning

confidence: 99%

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Characterization of covalently cross‐linked somatostatin receptors in hamster beta cell insulinoma

Cotroneo

Marie

Rosselin

1988

European Journal of Biochemistry

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The selective binding of somatostatin-28 (SS-28) to beta cells of hamster insulinoma was characterized using HPLC-purified '251-[Le~8,~-Trp22,Tyr25]SS-28 or lZ5I-SS-28. A single class of high-affinity sites (Kd = 53 f 5 pM) was observed with a binding capacity of 2.85 pmol/mg membrane protein. A large number of relatively low-affinity sites was found also. The order of potency of different peptides to inhibit '251-SS-28 binding is SS-28 > SS-14 > SMS-201-995 and the respective half-maximal inhibitory doses are 0.16 nM, 10 nM and 1000 nM. CCK8 and other active pancreatic peptides (glucagon, insulin, gastric inhibitory peptide, vasoactive intestinal peptide, oxyntomodulin) do not inhibit the SS-28 receptor binding. '251-SS-28-labeled beta membranes were successfully cross-linked using either the cleavable cross-linker dithiobis(succinimidy1propionate) (1 mM) alone or with a heterobifunctional agent, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB). In both cases five molecular components were revealed, after polyacrylamide gel electrophoresis of the membrane proteins and autoradiography, with the following molecular mass: 196-kDa, 132 kDa, 69 kDa, 45 kDa and 28 kDa. The labeling of 196-kDa, 132-kDa and 45-kDa species was specific in that they could be inhibited by unlabeled SS-28. The major labeled species corresponds to the 132-kDa band and no change in the mobility of this HSAB covalently bound SS-28 receptor was found after addition of dithiothreitol, suggesting that this specific receptor does not contain interchain disulphide bonds. The molecular mass of SS-28 receptors differs markedly from that of guineapig pancreatic acinar membranes, where a single 93-kDa protein is identified as a '251-SS-28 receptor site in comparative experiments. Both the binding kinetics and structural differences sustain the selective action of SS-28 in the endocrine pancreas.Somatostatin (SS), or somatotropic release inhibiting factor, was initially isolated from the ovine hypothalamus [l]. is mostly abundant in gut epithelium whereas somatostatin-14 [3] is mainly present in D cells of islets of Langerhans [3] and appears early in the developmental mammals [4]. Both inhibit, at different concentrations, the release of insulin and glucagon in vitro and in vivo [5, 61. The mechanism by which the somatostatin initiates the cellular response is the binding of somatostatin to specific receptors as shown in different tissues (reviewed in [7]). The somatostatin receptors have also been found in isolated rat islets of Langerhans [XI and in membrane of hamster insulinoma [9]. This insulinoma represents an invaluable model for somatostatin receptor studies, since it is composed of mainly beta cells [lo] and an array of other regulatory receptors (glucagon, oxyntomodulin, gastric inhibitory peptide) related to the beta cell function [ll -131 (reviewed in [14]). Furthermore, in this tumor the glucose-induced insulin release is inhibited by suggesting the presence of functional somatostatin receptors in these beta cells. Whereas the understandi...

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Section: Preparation and Purification Of Iodinated Ss-28supporting

confidence: 85%

Section: Preparation Of Pancreatic Membranesmentioning

confidence: 99%

Characterization of covalently cross‐linked somatostatin receptors in hamster beta cell insulinoma

Cotroneo

Marie

Rosselin

1988

European Journal of Biochemistry

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“…This fact most probably explains the glucagon-and GIP-like action of the peptide on pancreatic islets. However, with regard to the N-terminal extension of GLP-1 beyond the glucagon-like sequence it appears unlikely that the action of GLP-1 is mediated through glucagon receptors [18]; in fact, it has been shown that GLP-1 does not bind to glucagon receptors in the liver [7], so one can speculate that GLP-1 may act on its own or on the GIP-receptor on the pancreatic B-cell which has been recently identified [19].…”

Section: Discussionmentioning

confidence: 99%

Glucagon-like peptide-1 but not glucagon-like peptide-2 stimulates insulin release from isolated rat pancreatic islets

1985

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Summary. Glucagon-like peptide-1 and glucagon-like peptide-2 are encoded by the m-RNA of pancreatic preproglucagon. They show high conservation in different species and substantial sequence homology to glucagon. Because no definite biological activity of these peptides has been reported, we investigated the effect of synthetic C-terminally amidated glucagon-like peptide-t [1-36] and synthetic human glucagonlike peptide-2 [1-34] with a free C-terminus on insulin release from isolated precultured rat pancreatic islets in the presence of glucose. Glucagon-like peptide-1 stimulates insulin release at 10 and 16.7 mmol/1 glucose in a dose-dependent manner. Significant stimulation starts at 2.5 nmol/1 in the presence of 10 mmol/1 glucose and near maximal release is observed at 250 nmol/l, with approximately 100% increase over basal at both glucose concentrations. The peptide reaches 63% of the maximal stimulatory effect of glucagon. No stimulation occurs in the presence of 2.8 mmol/1 glucose. Glucagon-like peptide-2 has no effect on insulin secretion at any glucose concentration tested. It is concluded that glucagon-like peptide-t, in contrast to glucagon-like peptide-2, exhibits a glucose-dependent insulinotropic action on isolated rat pancreatic islets similar to that of glucagon and gastric inhibitory polypeptide.Key words: Glucagon-like peptide-t, glucagon-like peptide-2, insulin release, glucose dependency, isolated islets.Pancreatic preproglucagon m-RNA, the precursor of pancreatic glucagon, has been cloned and sequenced from different species using recombinant DNA-techniques [1][2][3][4][5]. Two other peptides have been found arranged in tandem on the same m-RNA in close proximity C-terminal to the glucagon precursor: glucagonlike peptide-I (GLP-1) and glucagon-like peptide-2 (GLP-2) comprising 36 and 34 amino acid residues, respectively. Both peptides show a different degree of sequence homology to pancreatic glucagon. The GLP-1 sequence is identical in the human, bovine and hamster precursor, whereas minor differences exist between the corresponding GLP-2 sequences. This substantial conservation in evolution and the close sequence homology to the glucagon molecule (GLP-I: 48% identical residues; GLP-2: 38%) indicates that GLP-1 and GLP-2 may play an important role of their own as hormones or local modulators. Recently they have been detected by specific radioimmunoassays in glucagonomas and in rat pancreatic islets [6], although they have not to date been isolated at the peptide level. Very little is known about a specific biological activity of these peptides. Hoosein and Gurd [7] could demonstrate a potent stimulation of rat hypothalamic and pituitary adenylate cyclase, whereas binding of glucagon to rat brain and liver membranes was not inhibited. GLP-1 may exert a weak stimulatory effect on exocrine pancreatic secretion in the rat [8].Suggesting a role in carbohydrate metabolism, we investigated the effect of synthetic GLP-I and GLP-2 on insulin release from isolated precultured rat pancreatic islets in th...

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“…It is considered to be one of the incretin candidates (Creutzfeldt & Ebert, 1985;Nauck et al 1989;Füessl et al 1990). Receptors for GIP have been characterized in different insulinomas and their cell lines Couvineau et al 1984;Maletti et al 1984;Amiranoff et al 1985;Maletti et al 1987), and it was shown that the binding of GIP produces a cyclic AMPmediated stimulation of insulin release . Stimulatory effects of GIP on insulin secretion and cyclic AMP in intact islets have also been observed by Szecowka et al (1982).…”

Section: Introductionmentioning

confidence: 99%

Binding specificity and signal transduction of receptors for glucagon-like peptide-1(7–36)amide and gastric inhibitory polypeptide on RINm5F insulinoma cells

Gallwitz¹,

Witt²,

Fölsch³

et al. 1993

Journal of Molecular Endocrinology

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Glucagon-like peptide-1(7-36)amide (GLP-1(7-36) amide) and gastric inhibitory polypeptide (GIP), peptides of the glucagon family, stimulate insulin secretion in vitro and in vivo. They possess high N-terminal sequence homology. Binding studies with 125I-labelled GIP and 125I-labelled GLP-1(7-36)amide were performed in RINm5F insulinoma cells to investigate receptor specificity and to compare both receptors directly. Both binding sites were highly ligand-specific: GIP did not bind to the GLP-1(7-36)amide receptor and vice versa. Both peptides increased intracellular cyclic AMP levels; GLP-1(7-36)amide was 100-fold more potent in stimulating cyclic AMP production when compared with GIP. At ranges of 1-10 nmol GLP-1(7-36)amide/l and 0.1-10 nmol GIP/l, corresponding to submaximal binding concentrations, the hormones showed an additive effect on cyclic AMP production. The N-terminal portion of GIP was important for binding, as GIP(1-30) showed almost full binding and biological activity. GIP(17-42) bound in a concentration-dependent manner with approximately 500-fold lower potency than GIP. At concentrations of up to 10 mumol GIP(17-42)/l no stimulation of cyclic AMP was observed.

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Evidence for and Characterization of Specific High Affinity Binding Sites for the Gastric Inhibitory Polypeptide in Pancreaticβ-Cells*

Cited by 38 publications

References 29 publications

Characterization of covalently cross‐linked somatostatin receptors in hamster beta cell insulinoma

Characterization of covalently cross‐linked somatostatin receptors in hamster beta cell insulinoma

Glucagon-like peptide-1 but not glucagon-like peptide-2 stimulates insulin release from isolated rat pancreatic islets

Binding specificity and signal transduction of receptors for glucagon-like peptide-1(7–36)amide and gastric inhibitory polypeptide on RINm5F insulinoma cells

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