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Dickinson CJ, DelValle J, Todisco A, Gantz I, Tong L, Finniss S, Yamada T. Canine prosomatostatin: isolation of a cDNA, regulation of gene expression, and characterization of post-translational processing intermediates. REGULATORY PEPTIDES 1996; 67:145-52. [PMID: 8988514 DOI: 10.1016/s0167-0115(96)00126-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Somatostatin is a tetradecapeptide (SS-14) initially isolated from the hypothalamus that is also found in D cells of the stomach and pancreas where it exerts an inhibitory action on a variety of gastrointestinal functions. Since many of concepts important to an understanding of gastrointestinal physiology are derived from experiments in the dog we examined somatostatin gene expression and post-translational processing in the canine fundus, antrum and pancreas. The canine somatostatin cDNA which is highly homologous to other known mammalian somatostatins was used to examine somatostatin expression in isolated canine fundic D-cells. Somatostatin expression induced by cholecystokinin (10(-8) M) was inhibited by the somatostatin analog, octreotide (10(-7) M). To examine somatostatin processing in the canine gut we noted that synthesis of SS-14 and somatostatin octacosapeptide (SS-28) involves endoproteolytic cleavage of prosomatostatin (proSS) at both paired and single basic amino-acid residues, respectively. Antisera capable of recognizing the amino-terminal residues of SS-28, SS-28(1-14) and SS-28(1-12) were characterized and identified concentrations of SS-28(1-12) but not SS-28(1-14) in the fundus, antrum and pancreas equivalent to those of SS-14. Since previous biosynthetic studies in canine fundic D-cells showed that SS-14 was synthesized without the appearance of a SS-28 intermediate, we hypothesize that proSS is sequentially cleaved at a dibasic site to produce SS-14 followed by monobasic cleavage that results in the formation of SS-28(1-12). Furthermore, equivalent amounts of SS-14 and SS-28(1-12) were co-released from canine fundic D-cells by CCK (10(-8) M) suggesting that the generation of these products occurs within the same regulated pathway of secretion.
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Affiliation(s)
- C J Dickinson
- Department of Pediatrics, University of Michigan Medical Center, Ann Arbor, USA
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2
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Rothenberg ME, Eilertson CD, Klein K, Zhou Y, Lindberg I, McDonald JK, Mackin RB, Noe BD. Processing of mouse proglucagon by recombinant prohormone convertase 1 and immunopurified prohormone convertase 2 in vitro. J Biol Chem 1995; 270:10136-46. [PMID: 7730317 DOI: 10.1074/jbc.270.17.10136] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The mouse tumor cell line alpha TC1-6 was used as a model system to examine the post-translational processing of proglucagon. Determination of the mouse preproglucagon cDNA sequence and comparison with the published sequences of rat and human preproglucagons revealed nucleic acid homologies of 89.1 and 84%, respectively, and amino acid homologies of 94 and 89.4%, respectively. Immunohistochemical analyses with antibodies directed against PC2 and glucagon colocalized both the enzyme and substrate within the same secretory granules. PC1 was also immunolocalized in secretory granules. Cells were metabolically labeled with [3H]tryptophan, and extracts were analyzed by reverse-phase high pressure liquid chromatography. Radioactive peptides with retention times identical to those of synthetic peptide standards were recovered and subjected to peptide mapping to verify their identities. To determine the potential role of PC1 and PC2 in proglucagon processing, 3H-labeled proglucagon was incubated in vitro with recombinant PC1 and/or immunopurified PC2. Both enzymes cleaved proglucagon to yield the major proglucagon fragment, glicentin, and oxyntomodulin, whereas only PC1 released glucagon-like peptide-I from the major proglucagon fragment. Neither PC1 nor PC2 processed glucagon from proglucagon in vitro. These results suggest a potential role for PC1 and/or PC2 in cleaving several of the normal products, excluding glucagon, from the mouse proglucagon precursor.
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Affiliation(s)
- M E Rothenberg
- Department of Anatomy and Cell Biology, Emory University, Atlanta, Georgia 30322, USA
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3
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Domeneghini C, Arrighi S. Immunohistochemical localization of different forms of somatostatin in the gastrointestinal tract of the calf. Acta Histochem 1994; 96:287-301. [PMID: 7856408 DOI: 10.1016/s0065-1281(11)80037-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The presence of two peptides that belong to the somatostatin family has been investigated in the calf gut. Somatostatin-14-like and Somatostatin-28-like peptides have been localized by a light microscopic immunohistochemical method. The method employed antibodies linked to colloidal gold particles that were revealed by a silver-enhancement step. Somatostatin-14-like peptide was only present in mucosal endocrine cells, which were detectable along the entire gut with the exceptions of the abomasal gastric proper glands and caecum. The cells were most abundant in cardiac and pyloric glands. Langerhans' islets also contained this type of endocrine cell. Somatostatin-28-like-immunoreactive endocrine cells were more abundant than the former cell type. They were present in the gastric proper glands and caecum where Somatostatin-14-like-immunoreactive cells were absent. They were as numerous as the former type of cell in the endocrine pancreas. The Somatostatin-28-like peptide was also detectable in the intramural nervous components of the abomasum and the intestine, in both perikarya and terminals. Our results show a possible heterogeneity of an endocrine cell type, which synthesizes and secretes somatostatin peptides. Our results also support the hypothesis that somatostatin-14 and somatostatin-28 peptides may have distinct functional roles, particularly in different species.
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Affiliation(s)
- C Domeneghini
- Institute of Domestic Animal Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, University of Milan, Italy
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4
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8 Molecular Aspects of Pancreatic Peptides. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/s1546-5098(08)60069-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
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5
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Cawley NX, Noe BD, Loh YP. Purified yeast aspartic protease 3 cleaves anglerfish pro-somatostatin I and II at di- and monobasic sites to generate somatostatin-14 and -28. FEBS Lett 1993; 332:273-6. [PMID: 8104828 DOI: 10.1016/0014-5793(93)80648-e] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Anglerfish somatostatin-14 (SS-14) and somatostatin-28 (aSS-28) are derived from pro-somatostatin I (aPSS-I) and pro-somatostatin II (PSS-II), respectively. Purified yeast aspartic protease 3 (YAP3), was shown to cleave aPSS-I at the Arg81-Lys82 to yield SS-14 and Lys-1SS-14. In contrast, YAP3 cleaved aPSS-II only at the monobasic residue, Arg73 to yield aSS-28. Since the paired basic and monobasic sites are present in both precursors, the results indicate that the structure and conformation of these substrates dictate where cleavage occurs. Furthermore, the data show that YAP3 has specificity for both monobasic and paired basic residues.
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Affiliation(s)
- N X Cawley
- Section on Cellular Neurobiology, National Institutes of Health, Bethesda, MD 20892
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6
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Jung LJ, Kreiner T, Scheller RH. Prohormone structure governs proteolytic processing and sorting in the Golgi complex. RECENT PROGRESS IN HORMONE RESEARCH 1993; 48:415-436. [PMID: 8441853 DOI: 10.1016/b978-0-12-571148-7.50019-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- L J Jung
- Howard Hughes Medical Institute, Department of Molecular and Cellular Physiology, Beckman Center, Stanford University, California 94305
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8
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9
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Smeekens SP, Chan SJ, Steiner DF. The biosynthesis and processing of neuroendocrine peptides: identification of proprotein convertases involved in intravesicular processing. PROGRESS IN BRAIN RESEARCH 1992; 92:235-46. [PMID: 1302878 DOI: 10.1016/s0079-6123(08)61179-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- S P Smeekens
- Department of Biochemistry and Molecular Biology, University of Chicago, IL
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10
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Bourbonnais Y, Danoff A, Thomas D, Shields D. Heterologous expression of peptide hormone precursors in the yeast Saccharomyces cerevisiae. Evidence for a novel prohormone endoprotease with specificity for monobasic amino acids. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98824-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Roth WW, Mackin RB, Spiess J, Goodman RH, Noe BD. Primary structure and tissue distribution of anglerfish carboxypeptidase H. Mol Cell Endocrinol 1991; 78:171-8. [PMID: 1778303 DOI: 10.1016/0303-7207(91)90120-h] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Most peptide hormones are synthesized as part of larger precursor proteins which must be processed after translation to generate bioactive peptides. This usually involves cleavage of the precursor by an endopeptidase at sites marked by basic amino acids, followed by removal of N- or C-terminal basic residues by the action of an aminopeptidase or carboxypeptidase. These processing events have been observed in a variety of species, from yeast to mammals. As part of an effort to characterize prohormone processing enzymes in the anglerfish, Lophius americanus, we have cloned and sequenced a cDNA for the fish prohormone processing carboxypeptidase H (CPH). Polyadenylated RNA from anglerfish (AF) islet organs was used to construct a cDNA library in phage lambda gt11. The library was screened with a probe derived from the cDNA for rat CPH. A 2400 base pair AF cDNA clone was isolated. This cDNA encodes a polypeptide which is similar in size and composition to mammalian CPH. The sequence data indicate that the AF CPH precursor is a 454 amino acid polypeptide. The derived amino acid sequence of the putative fish CPH is 81% homologous to the rat and bovine CPH enzymes. Significantly, all of the amino acid residues thought to be important for metal ion and substrate binding, glycosylation, and catalytic activity of mammalian CPH are conserved in the fish enzyme. Northern hybridization using RNA from AF tissues indicates that a 2.5 kb fish CPH mRNA is expressed in brain, pituitary and islet organs, but not in other tissues which do not secrete peptide hormones.
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Affiliation(s)
- W W Roth
- Department of Anatomy and Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
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12
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Shennan KI, Smeekens SP, Steiner DF, Docherty K. Characterization of PC2, a mammalian Kex2 homologue, following expression of the cDNA in microinjected Xenopus oocytes. FEBS Lett 1991; 284:277-80. [PMID: 2060650 DOI: 10.1016/0014-5793(91)80703-6] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A human insulinoma cDNA (PC2) that encodes a protein homologous to the Kex2/subtilisin-like proteinases has recently been described [1990, J. Biol. Chem. 265, 2997-3000]. In order to characterise the associated proteinase activity, mRNA encoding PC2 was synthesised in vitro and microinjected into Xenopus oocytes. The proteinase activity released into the media from oocytes microinjected with PC2 mRNA was assayed using small peptide fluorogenic substrates. Boc.Gln.Arg.Arg aminomethyl coumarin was hydrolysed in a Ca(2+)-dependent manner, but substrate analogues bearing a single basic aminoacid were not. The substrate specificity, inhibitor profile, and pH optimum of 5.5 were compatible with an involvement of PC2 in prohormone processing in mammalian cells.
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Affiliation(s)
- K I Shennan
- Department of Medicine, University of Birmingham, Queen Elizabeth Hospital, UK
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13
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Heterologous expression of preprosomatostatin. Intracellular degradation of prosomatostatin-II. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)92919-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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14
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15
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Nakayama K, Kim WS, Nakagawa T, Nagahama M, Murakami K. Substrate specificity of prorenin converting enzyme of mouse submandibular gland. Analysis using site-directed mutagenesis. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(17)45322-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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16
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Abstract
Several peptides are generated from prosomatostatin (proSS) in addition to somatostatin-14 (SS-14) and somatostatin-28 (SS-28). These are SS-28(1-12), proSS(1-76) and, as shown more recently, proSS(1-63) and antrin. Important variations in the proportion of these molecular forms are seen among different tissues and among different species. Processing of the precursor in the human brain yields minimal quantities of SS-28(1-12) and high levels of proSS(1-76), namely in cortical areas and in the bed nucleus of the stria terminalis. This is in contrast with findings in rat brain, where SS-28(1-12) is a predominant molecular form. Antrin, which corresponds to proSS(1-10), reaches its highest concentration in the antral portion of the stomach (117 +/- 13 pmol/g wet weight), where it is found in secretory granules of delta cells. We observed an inverse relationship between levels of antrin and proSS(1-63) after chromatography of various tissue extracts. This suggests a precursor-product relationship between these two peptides.
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Affiliation(s)
- R Benoit
- Montreal General Hospital, Quebec, Canada
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17
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Sevarino KA, Ventimiglia R, Stork P. Processing and intracellular sorting of anglerfish and rat preprosomatostatins in mammalian endocrine cells. Metabolism 1990; 39:26-9. [PMID: 1976215 DOI: 10.1016/0026-0495(90)90203-o] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Rat preprosomatostatin (rPPSS) is processed to two distinct end products in a tissue-specific manner. The analogous end products in anglerfish are derived from separate precursors, anglerfish preprosomatostatins-1 and -2 (a(1)PPSS and a(II)PPSS). This report reviews experiments demonstrating that in mammalian cells, the cell of expression, not precursor structure, determines the processing fate of the preprosomatostatins. A fusion precursor of a(II)PPSS and rPPSS was expressed in mammalian cell lines to determine that the amino-terminal 78 residues of rPPSS contain a sorting signal that directs the precursor into a regulated secretory pathway wherein proteolytic processing occurs. Preliminary studies of rPPSS pro-region mutations are presented that attempt to further localize this sorting signal.
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Affiliation(s)
- K A Sevarino
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06508
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18
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Abstract
The enzymes responsible for performing cleavage of propeptides at basic amino acids have proven difficult to characterize. Using the processing of anglerfish islet prosomatostatin (PSS) as a model system, we are pursuing the characterization of both a single basic amino acid-specific and a dibasic amino acid-specific converting enzyme. We describe here the model system and protein isolation methods that have allowed significant progress toward complete characterization of the somatostatin-generating propeptide converting enzymes (PCEs).
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Affiliation(s)
- R B Mackin
- Max Planck Research Program, Salk Institute for Biological Studies, La Jolla, CA
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19
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Rat pro-atrial natriuretic factor expression and post-translational processing in mouse corticotropic pituitary tumor cells. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38532-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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20
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Multiple tachykinins are produced and secreted upon post-translational processing of the three substance P precursor proteins, α-, β-, and γ-preprotachykinin. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)84871-8] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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21
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Beinfeld MC, Bourdais J, Morel A, Kuks PF, Cohen P. Characterization of a somatostatin-28 generating metallo-endoprotease from rat brain cytosol. Biochem Biophys Res Commun 1989; 160:968-76. [PMID: 2566306 DOI: 10.1016/0006-291x(89)92530-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Brain cytosol contains a neutral metallo-protease of about 80,000 which cleaves a substrate containing the site at which mammalian prosomatostatin is cleaved to generate somatostatin 28 in vivo. This represents a cleavage on the carboxyl side of a single arginine residue at an Arg-Ser bond. The enzyme was unable to cleave several other substrates containing single arginine residues or two substrates containing an Arg-Lys or Lys-Arg pair. When it was incubated with anglerfish pancreatic prosomatostatin, it produced significant quantities of a peptide which co-eluted with somatostatin 28 II. Based on the ability of this enzyme to cleave small and large substrates related to somatostatin, it is a potential candidate for the enzymes which cleaves prosomatostatin in vivo.
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Affiliation(s)
- M C Beinfeld
- Université Pierre et Marie Curie, Unité de Recherche Associée 003, Paris, France
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22
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Sevarino KA, Stork P, Ventimiglia R, Mandel G, Goodman RH. Amino-terminal sequences of prosomatostatin direct intracellular targeting but not processing specificity. Cell 1989; 57:11-9. [PMID: 2564811 DOI: 10.1016/0092-8674(89)90167-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Rat preprosomatostatin (rPPSS) is processed to two bioactive peptides, somatostatin-14 and somatostatin-28. In anglerfish islets, the two peptides are synthesized by distinct cell types and are derived from different precursors, anglerfish preprosomatostatin-1 (a(I)PPSS) and anglerfish preprosomatostatin-2 (a(II)PPSS). To determine the basis of the differential processing, we introduced a(I)PPSS or a(II)PPSS expression vectors into mammalian endocrine cell lines that can accomplish both patterns of processing. Both precursors were processed identically, indicating that cellular factors must determine the processing pattern. Although similar processing sites are present in both precursors, high levels of unprocessed anglerfish prosomatostatin-2 were secreted constitutively from the transfected cells. A hybrid protein containing the leader sequence and a portion of the pro-region of rPPSS fused to the carboxy-terminal third of a(II)PPSS was processed and secreted via a regulated pathway. We conclude that the amino-terminal 78 residues of rPPSS contain sufficient information to correct the targeting deficiency of a(II)PPSS in mammalian endocrine cell lines.
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Affiliation(s)
- K A Sevarino
- Department of Medicine, New England Medical Center Hospital, Boston, Massachusetts 02111
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24
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Characterization of an endoprotease from rat small intestinal mucosal secretory granules which generates somatostatin-28 from prosomatostatin by cleavage after a single arginine residue. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)83765-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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25
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Danoff A, Shields D. Differential translation of two distinct preprosomatostatin messenger RNAs. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37614-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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26
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Morel A, Kuks PF, Bourdais J, Cohen P. Prosomatostatin processing in anglerfish brain, gut and pancreas. Biochem Biophys Res Commun 1988; 151:347-54. [PMID: 2894830 DOI: 10.1016/0006-291x(88)90600-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The distribution of somatostatin immunoreactive forms in three tissues of the anglerfish (Lophius piscatorius L.) was analyzed by a combination of gel permeation, High Pressure Liquid Chromatography and amino acid analysis. The data indicate that prosomatostatins I and II are expressed in both neural and gastro-intestinal tissues and that their post-translational processing gives rise to somatostatin-14 I, somatostatin-28 II and to some of its hydroxylysine23-derivative, respectively. It is concluded that, in contrast to the mammals, production of two somatostatins in the Teleostean fish requires two structurally distinct precursors whose processing operates in a fixed pattern rather than in a tissue-specific manner.
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Affiliation(s)
- A Morel
- Université Pierre et Marie Curie, Groupe de Neurobiochimie Cellulaire et Moléculaire, UA 554 au CNRS, Paris, France
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27
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Andrews PC, Nichols R, Dixon JE. Post-translational processing of preprosomatostatin-II examined using fast atom bombardment mass spectrometry. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)45262-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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