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Dores RM, Baron AJ. Evolution of POMC: origin, phylogeny, posttranslational processing, and the melanocortins. Ann N Y Acad Sci 2011; 1220:34-48. [DOI: 10.1111/j.1749-6632.2010.05928.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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2
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Ozawa A, Speaker RB, Lindberg I. Enzymatic characterization of a human acyltransferase activity. PLoS One 2009; 4:e5426. [PMID: 19412546 PMCID: PMC2672172 DOI: 10.1371/journal.pone.0005426] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Accepted: 04/07/2009] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Non-histone protein acylation is increasingly recognized as an important posttranslational modification, but little is known as to the biochemical properties of protein serine acylating enzymes. METHODOLOGY/PRINCIPAL FINDINGS We here report that we have identified a metal-stimulated serine octanoyltransferase activity in microsomes from human erythroleukemic (HEL) cells. The HEL acylating enzyme was linear with respect to time and protein, exhibited a neutral pH optimum (stimulated by cobalt and zinc), and inhibited by chelating reagents. Hydroxylamine treatment removed most, but not all, of the attached radioactivity. A salt extract of microsomal membranes contained the major portion of enzyme activity, indicating that this acyltransferase is not an integral membrane protein. Sucrose density fractionation showed that the acyltransferase activity is concentrated in the endoplasmic reticulum. In competition experiments, the acyltransferase was well inhibited by activated forms of fatty acids containing at least eight to fourteen carbons, but not by acetyl CoA. The zinc-stimulated HEL acyltransferase did not octanoylate proenkephalin, proopiomelanocortin, His-tagged proghrelin, or proghrelin lacking the amino-terminal His-tag stub of Gly-Ala-Met. The peptides des-acyl ghrelin and ACTH were also not acylated; however, des-acyl ghrelin containing the N-terminal tripeptide Gly-Ala-Met was acylated. Mutagenesis studies indicated a requirement for serine five residues from the amino terminus, reminiscent of myristoyl transferase, but not of ghrelin acylation. However, recombinant myristoyl transferase could not recapitulate the hydroxylamine sensitivity, zinc-stimulation, nor EDTA inhibition obtained with HEL acyltransferase, properties preserved in the HEL cell enzyme purified through four sequential chromatographic steps. CONCLUSIONS/SIGNIFICANCE In conclusion, our data demonstrate the presence of a zinc-stimulated acyltransferase activity concentrated in the endoplasmic reticulum in HEL cells which is likely to contribute to medium-chain protein lipidation.
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Affiliation(s)
- Akihiko Ozawa
- Department of Anatomy and Neurobiology, University of Maryland—Baltimore, Baltimore, Maryland, United States of America
| | - Richard B. Speaker
- Department of Anatomy and Neurobiology, University of Maryland—Baltimore, Baltimore, Maryland, United States of America
| | - Iris Lindberg
- Department of Anatomy and Neurobiology, University of Maryland—Baltimore, Baltimore, Maryland, United States of America
- * E-mail:
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3
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Cangemi L, Adage T, Morabito A, Portaleone P. N-Acetyltransferase mechanism for alpha-melanocyte stimulating hormone regulation in rat ageing. Neurosci Lett 1995; 201:65-8. [PMID: 8830315 DOI: 10.1016/0304-3940(95)12135-q] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
alpha-Melanocyte stimulating hormone (alpha-MSH) is a proopiomelanocortin-derived peptide involved in such behavioural activities as arousal, grooming, memory, learning and attention. Because of these effects, alpha-MSH can be considered the 'adaptation neuropeptide'. Two alpha-MSH major forms were described: acetyl alpha-MSH and des-acetyl alpha-MSH. Since the acetylated form of alpha-MSH is biologically significantly more effective than des-acetyl alpha-MSH, we studied the activity of N-acetyltransferase, the enzyme responsible for MSH acetylation, during ageing in rat hippocampus and pituitary. We observed a substantial decrease of enzyme activity during lifetime, suggesting that the lower synthesis of the more efficient acetylated alpha-MSH form can be related to the reduced adaptive capabilities of aged subjects.
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Affiliation(s)
- L Cangemi
- Institute of Pharmacology and Experimental Therapy, University of Torino, Italy
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4
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Abstract
Cyclic dipeptides are among the simplest peptide derivatives commonly found in nature. Most cyclic dipeptides found to date appear to have emerged as by-products of fermentation and food processing. However, many are endogenous to members of animal and plant kingdoms; these include cyclo(Pro-Leu), cyclo(Pro-Val), cyclo(Pro-Phe), cyclo(Ala-Leu), cyclo(Pro-Tyr), cyclo(Pro-Trp), and cyclo(His-Pro). Although the five cyclic dipeptides--cyclo(His-Pro), cyclo(Leu-Gly), cyclo(Tyr-Arg), cyclo(Asp-Pro), and cyclo(Pro-Phe)--exhibit interesting physiological and/or pharmacological activities in mammals, only one of these, cyclo(His-Pro), has been conclusively shown to be endogenous to mammals. On the other hand, cyclo(Leu-Gly), cyclo(Tyr-Arg), and cyclo(Asp-Pro) are structurally related to endogenous peptides Pro-Leu-Gly-NH2 (melanocyte-stimulating hormone release inhibiting factor), Tyr-Arg (kyotorphin), and Val-Pro-Asp-Pro-Arg (enterostatin), respectively, which may serve as precursor peptides. It needs to be determined, however, whether these peptides can indeed result from the processing of their respective precursors. In conclusion, it appears that cyclic dipeptides are a relatively unexplored class of bioactive peptides that may hold great promise for the future.
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Affiliation(s)
- C Prasad
- Department of Medicine, Louisiana State University Medical Center, New Orleans 70112, USA
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5
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Dores RM, Keller H, White Y, Marra LE, Youson JH. Detection of N-acetylated forms of alpha-MSH and beta-endorphin in the intermediate pituitary of the holostean fishes, Lepisosteus spatula, Lepisosteus osseus, and Amia calva. Peptides 1994; 15:483-7. [PMID: 7937324 DOI: 10.1016/0196-9781(94)90210-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Acid extracts of the intermediate pituitaries of the gars, L. spatula and L. osseus, were fractionated by Sephadex G-50 column chromatography and analyzed by radioimmunoassay. This procedure revealed that immunoreactive forms of N-acetylated beta-endorphin- and alpha-MSH-sized material were present in equimolar amounts and represented the major end products of the POMC biosynthetic pathway in these species. Cation-exchange chromatography indicated that multiple N-acetylated forms of beta-endorphin were present in the intermediate pituitaries of the two species of gar, and that these forms differed in their net positive charge and in their apparent molecular weight. Reversed-phase HPLC analysis of the alpha-MSH-related material indicated that up to 90% of the total MSH in the pituitary of the gar was N-acetylated. Furthermore, the predominant form of alpha-MSH in both species of gar was N,O-diacetyl-ACTH(1-13)-NH2. Nearly identical results were obtained following the analysis of alpha-MSH-related peptides in the intermediate pituitary of the bowfin, A. calva. The pattern of posttranslational processing of POMC observed in the intermediate pituitaries of holostean fishes is very similar to the processing events observed in lungfishes, turtles, and mammals; hence, the processing of POMC has been remarkably conserved during vertebrate evolution.
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Affiliation(s)
- R M Dores
- University of Denver, Department of Biological Sciences, CO 80208
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6
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Dores RM, Steveson TC, Price ML. A view of the N-acetylation of alpha-melanocyte-stimulating hormone and beta-endorphin from a phylogenetic perspective. Ann N Y Acad Sci 1993; 680:161-74. [PMID: 8390150 DOI: 10.1111/j.1749-6632.1993.tb19682.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- R M Dores
- Department of Biological Sciences, University of Denver, Colorado 80208
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7
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Lee FJ, Lin LW, Smith JA. Model peptides reveal specificity of N alpha-acetyltransferase from Saccharomyces cerevisiae. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38436-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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8
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Kamitani K, Narita K, Sakiyama F. Purification and Characterization of Hen Oviduct Nα-Acetyltransferase. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)51613-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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9
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Lee FJS, Lin LW, Smith JA. Molecular Cloning and Sequencing of a cDNA Encoding Nα-Acetyltransferase from Saccharomyces cerevisiae. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)63863-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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10
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Abstract
The amino terminal sequence of the 13-kilodalton (kD) polypeptide present in purified Drosophila acetyl-CoA: choline-O-acetyltransferase (EC 2.3.1.6) was determined, and its position in the sequence of the intact enzyme was located. Enzyme polypeptides for sequencing were obtained from native enzyme protein by denaturation, followed by fractionation on reverse-phase HPLC. The 13-, 54-, and 67-kD polypeptides recovered from the separation were subjected to amino terminal sequencing. Only the 13-kD fragment yielded a sequence. The 67- and 54-kD polypeptides appeared completely blocked to gas-phase Edman sequencing. The location of the amino terminal sequence from the 13-kD polypeptide in the cDNA-deduced enzyme sequence indicated that this fragment represents the carboxyl portion of the 67-kD enzyme, with the 54-kD polypeptide providing the amino terminal portion. The proteolysis that gave rise to the 13-kD polypeptide occurred at the carboxyl side of a monobasic lysine residue. An earlier comparison of the enzyme from Drosophila and pigs indicated that the cleaved lysine may be a conserved residue in the porcine enzyme. The cleaved enzyme region characterized in this study does not coincide with the regions of high homology found in the two enzymes, but hydrophilicity profiles generated for this area showed similarities.
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Affiliation(s)
- J R Slemmon
- Department of Biochemistry, University of Rochester, School of Medicine and Dentistry, NY 14642
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11
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Affiliation(s)
- C Prasad
- Department of Medicine, Louisiana State University Medical Center, New Orleans 70112
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12
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Purification and characterization of an N alpha-acetyltransferase from Saccharomyces cerevisiae. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68130-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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13
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Cotranslational amino-terminal processing of cytosolic proteins. Cell-free expression of site-directed mutants of human hemoglobin. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68497-2] [Citation(s) in RCA: 100] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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14
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Dores RM, Schenk LM, Rothenberg ME. Isolation of alpha-melanotropin from the pars intermedia of the larval amphibian, Ambystoma tigrinum. Gen Comp Endocrinol 1987; 68:322-30. [PMID: 3428562 DOI: 10.1016/0016-6480(87)90044-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effect of background adaptation on the steady-state levels of alpha-melanotropin in the pars intermedia of the larval amphibian. Ambystoma tigrinum, was investigated. Acid extracts of pars intermedia obtained from light-adapted and dark-adapted animals were analyzed by radioimmunoassay following Sephadex gel filtration chromatography, reverse-phase HPLC, and Sulfopropyl Sephadex cation-ion-exchange chromatography. For both background adaptation conditions similar results were obtained. The major form of alpha-melanotropin present in the pars intermedia has the following properties: (1) an apparent molecular mass of 1.5 kDa; (2) a net charge at pH 3.5 of +4; and (3) a retention time following reverse-phase HPLC similar to that of synthetic ACTH(1-13)amide. In dark-adapted animals a minor form of alpha-melanotropin which has a net charge of +3 at pH 3.5 was also detected. The latter form represented approximately 10% of the total alpha-melanotropin immunoreactivity in the pars intermedia of dark-adapted animals. These results strongly suggest that the predominant form of alpha-melanotropin in the pars intermedia of larval A. tigrinum is a nonacetylated ACTH(1-13)amide-like polypeptide.
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Affiliation(s)
- R M Dores
- University of Denver, Department of Biological Sciences, Colorado 80208
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16
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Kasten-Jolly J, Abraham EC. Human fetal hemoglobin synthesis and its NH2-terminal acetylation in a rabbit reticulocyte lysate translational system. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 866:125-34. [PMID: 2420364 DOI: 10.1016/0167-4781(86)90109-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The biosynthesis of the acetylated (Hb FIc) and the non-acetylated (Hb F0) human fetal hemoglobin components has been examined in a cell-free translational system. The poly(A)-RNA was isolated from umbilical cord blood samples and translated in the heterologous translational system derived from rabbit reticulocyte lysates in the presence of labeled amino acid(s) or acetyl-CoA. The amount of each hemoglobin or globin chain made in the system was determined by separating the synthesis products by cation-exchange chromatographic methods. The in vitro synthesis ratios were close to the FIc/Ftotal values of the respective hemolysates. The same conclusion could be reached by determining the specific activity ratios of Hb FIc/Hb F0. Co-migration of radioactivity peaks with absorbance peaks indicated the synthesis of that hemoglobin or globin chain. Confirmation of the synthesis of true gamma 0 and gamma Ic was accomplished by high-pressure liquid chromatographic separation of 3H-labeled tryptic peptides. Each peptide corresponded well with the radioactivity peak. Labeled acetyl-group incorporation into Hb FIc and gamma IcT-1 provided direct evidence for acetylation of gamma chains in Hb FIc. The data indicate that the mRNA itself dictates whether a protein is acetylated and, if so, to what extent. The control appears to be not unique to the human red cell system.
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17
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Chappell MC, O'Donohue TL, Millington WR, Kempner ES. The size of enzymes acetylating alpha-melanocyte-stimulating hormone and beta-endorphin. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(17)36057-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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18
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Wolter HJ. Adrenocorticotropin and alpha-melanotropin in the myenteric plexus of the rat duodenum: an electron microscopic study. Brain Res 1985; 360:10-4. [PMID: 3000527 DOI: 10.1016/0006-8993(85)91214-4] [Citation(s) in RCA: 6] [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
Adrenocorticotropin (ACTH) immunoreactivity was localized at the ultrastructural level as positive 'cores' within large dense-cored vesicles (LDVs) of axons and dendrites of the rat duodenum. The immunostained vesicle 'cores' were 35-50 nm in mean diameter, corresponding to 'cores' of LDVs with a mean diameter of 80-90 nm. alpha-melanotropin (alpha-MSH) was detected also within LDVs, expressing the same mean diameter as ACTH-stained vesicles. alpha-MSH and ACTH were localized only within structures belonging to the enteric nervous system of the rat duodenum. alpha-MSH and ACTH, as detected by immunostaining, were absent in endocrine cells of the rat duodenum. These findings suggest the possibility that these peptides may have important physiological roles in the rat duodenum.
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Gibson TR, Glembotski CC. Acetylation of alpha MSH and beta-endorphin by rat neurointermediate pituitary secretory granule-associated acetyltransferase. Peptides 1985; 6:615-20. [PMID: 2999728 DOI: 10.1016/0196-9781(85)90162-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
ACTH(1-8) and ACTH(9-13)NH2 were used as potential enzyme inhibitors to begin examining the relationship between the acetylation of ACTH- and beta-endorphin-related peptides. ACTH(1-8) was a potent inhibitor of the acetylation of both ACTH- and beta-endorphin-related peptides, whereas ACTH(9-13)NH2 was an effective inhibitor only of the acetylation of ACTH-related substrates. This inhibition pattern indicated that there may be an unusual interaction between some ACTH- and beta-endorphin-related peptides as substrates for the acetyltransferase. Utilizing HPLC to separate ACTH- and beta-endorphin-related peptides present in the same reaction mixture, ACTH(1-14) and beta-endorphin(1-27) at Km and saturating concentrations were used as substrates to examine the ability of one peptide substrate to affect the acetylation of the other. It was observed that the acetylation of ACTH(1-14), even at Km concentration, was relatively unaffected by the presence of beta-endorphin(1-27). However, the acetylation of beta-endorphin(1-27) was significantly reduced by the presence of ACTH(1-14). This preferential acetylation of ACTH-related peptides over the acetylation of beta-endorphin-related peptides might have physiological importance under some conditions.
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20
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L'Hernault SW, Rosenbaum JL. Chlamydomonas alpha-tubulin is posttranslationally modified by acetylation on the epsilon-amino group of a lysine. Biochemistry 1985; 24:473-8. [PMID: 3919761 DOI: 10.1021/bi00323a034] [Citation(s) in RCA: 361] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Previous work has shown that the principal alpha-tubulin within Chlamydomonas reinhardtii flagellar axonemes differs from the major alpha-tubulin in the cell body. These two variants of alpha-tubulin are related to one another since posttranslational modification of the cell body form converts it to the axonemal form. When flagella are induced to assemble in the absence of de novo protein synthesis, tritiated acetate can be used to posttranslationally label alpha-tubulin in vivo, and under these conditions, no other flagellar polypeptides exhibit detectable labeling [L'Hernault, S. W., & Rosenbaum, J. L. (1983) J. Cell Biol. 97, 258-263]. In the present report, this labeling method has been used to provide material for chemical analysis of the tritiated moiety that is posttranslationally added to flagellar alpha-tubulin. This radioactivity was volatile after acid hydrolysis, suggesting that the posttranslational modification is the addition of neither an amino acid nor carbohydrate. Treatment of posttranslationally 3H-labeled alpha-tubulin with hydrazine yields radioactive acetylhydrazine, indicating that the moiety involved in posttranslational modification is an acetyl group. Analysis of complete proteolytic digests by thin-layer chromatography has revealed that this acetyl group is located on the epsilon-amino group of a flagellar alpha-tubulin lysine residue.
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Driessen HP, de Jong WW, Tesser GI, Bloemendal H. The mechanism of N-terminal acetylation of proteins. CRC CRITICAL REVIEWS IN BIOCHEMISTRY 1985; 18:281-325. [PMID: 3902358 DOI: 10.3109/10409238509086784] [Citation(s) in RCA: 192] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
N alpha-acetylation is almost exclusively restricted to eukaryotic structural proteins. As a rule it is a post-initiational process, requiring the presence of the enzyme N alpha-acetyltransferase and the acetyl donor acetylcoenzyme A. N alpha-acetyltransferases appear to have a narrow substrate specificity, which is very similar for enzymes from different tissues and species. Amino acids predominantly present at the N terminus of N alpha-acetylated proteins are alanine, serine, and methionine. The occurrence of these residues is apparently a prerequisite for acetylation. The region following these amino acids is also important. If methionine is at the N terminus, the second position is always occupied by a strongly hydrophilic amino acid. Two- and three-dimensional structural characteristics of the protein do not seem to play a major role in N alpha-acetylation. Up to now the exact function for N alpha-acetylation is not known.
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22
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Glembotski CC. The alpha-amidation of alpha-melanocyte stimulating hormone in intermediate pituitary requires ascorbic acid. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)90653-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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23
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Structure of the 22-residue somatostatin from catfish. An O-glycosylated peptide having multiple forms. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)90688-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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24
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Kasten-Jolly J, Taketa F. The amino terminal acetylation of cat globin chains and their tryptic peptides. Life Sci 1984; 35:1623-32. [PMID: 6434892 DOI: 10.1016/0024-3205(84)90172-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Cat blood contains two major hemoglobins, HbA and HbB, both of which are synthesized within the same red cell. They contain identical alpha chains but different beta chains. HbB is somewhat unusual in that it contains beta chains that are modified by N alpha-acetylation. Although the selective amino terminal acetylation of the beta chain of cat HbB occurs during nascent peptide chain growth, it can also occur after completion of globin chain synthesis and its assembly into hemoglobin. However, the latter process is not as efficient as the former, and it occurs non-enzymatically. Two peptides in a mixture of tryptic peptides from cat HbA and non-acetylated cat HbB contain serine at their amino terminus. One is the octapeptide, non-acetylated B- beta T-1, and the other is the tetrapeptide, alpha T-2, derived from both HbA and HbB. We provide evidence here that in a mixture of soluble tryptic peptides, acetylation of alpha T-2 takes place in the presence of acetyl-CoA and ribosomal acetyltransferase at pH 7.0. The amino terminal acetylation requires the presence of an acetyltransferase.
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Schöneshöfer M, Goverde HJ. Corticotropin in human plasma. General considerations. SURVEY OF IMMUNOLOGIC RESEARCH 1984; 3:55-63. [PMID: 6326236 DOI: 10.1007/bf02918598] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Abstract
The rat pituitary contains an enzyme which will acetylate certain ACTH fragments using acetyl coenzyme A. This acetyltransferase activity was found in all three lobes of the rat pituitary as well as in all other tissues examined. The rat pituitary enzyme appears to be largely particulate in nature. The enzyme sedimenting at 27,000 and 100,000 g had specific activities 4-10 times greater than the soluble fraction. The acetyltransferase activity was dependent on substrate concentration (ACTH) and pH, was linear with time, and was inactivated at 55 degrees. The enzyme would acetylate ACTH(1-24), (1-10), and ACTH(4-10), but would not use ACTH(2-10), (3-10), or ACTH(1-8) as substrates. The apparent Km values for the substrates were as follows: AcCoA, 2.2 microM, ACTH(1-24), 4.2 microM; ACTH(1-10), 96 microM; and ACTH(4-10), 37 microM.
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Mains RE, Eipper BA, Glembotski CC, Dores RM. Strategies for the biosynthesis of bioactive peptides. Trends Neurosci 1983. [DOI: 10.1016/0166-2236(83)90100-5] [Citation(s) in RCA: 128] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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31
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Driessen HP, Bloemendal H, de Jong WW, Tesser GI. Synthesis of an analogue of alpha-MSH-(1-10)-decapeptide as a substrate for enzymatic N alpha-acetylation. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1982; 20:289-97. [PMID: 7174194 DOI: 10.1111/j.1399-3011.1982.tb00893.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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32
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Driessen HP, de Jong WW, Tesser GI, Bloemendal H. A rapid and specific assay for N alpha-acetyltransferase activity. Anal Biochem 1982; 125:352-7. [PMID: 7181093 DOI: 10.1016/0003-2697(82)90016-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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33
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Glembotski CC. Characterization of the peptide acetyltransferase activity in bovine and rat intermediate pituitaries responsible for the acetylation of beta-endorphin and alpha-melanotropin. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)34046-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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34
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Abstract
The biosynthesis of alpha-MSH, beta-endorphin and ACTH in the pituitary is reviewed. These neuropeptides are synthesized from a common pro-protein, pro-opiomelanocortin. The pro-protein is cleaved intragranularly, at pairs of basic residues in the molecule to yield the respective peptide products. An unique, thiol protease (pro-opiocortin converting enzyme) and a carboxypeptidase B-like enzyme, both localized within pituitary secretory granules and having a pH optimum of 5-6, appear to be involved in the proteolytic processing of pro-opiomelanocortin.
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Chappell MC, Loh YP, O'Donohue TL. Evidence for an opiomelanotropin acetyltransferase in the rat pituitary neurointermediate lobe. Peptides 1982; 3:405-10. [PMID: 6289279 DOI: 10.1016/0196-9781(82)90100-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Results of this study demonstrate two distinct forms of acetyltransferase activity which will acetylate alpha-MSH. These acetyltransferases are distinguished by pH optima, subcellular distribution and sensitivity to magnesium and several solubilizing detergents. A general acetyltransferase, as characterized in the rat pituitary anterior lobe and lens, has a pH optima of 7.4 and is inhibited by magnesium. Subcellular fractionation of anterior and neurointermediate lobes revealed that this acetyltransferase is primarily localized in the cytosol fraction of these tissues. An alpha-MSH acetyltransferase (MAT) and a beta-endorphin acetyltransferase (EAT) have a pH optima of 6.0-6.6, are inhibited by detergents, and are specifically localized in the secretory granules of the neurointermediate lobe. Comparative studies of MAT and EAT suggest a single enzyme responsible for the acetylation of opioid and melanotropin peptides, and we term this enzyme opiomelanotropin acetyltransferase (OMAT).
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O'Donohye TL, Handelmann GE, Miller RL, Jacobowitz DM. N-acetylation regulates the behavioral activity of alpha-melanotropin in a multineurotransmitter neuron. Science 1982; 215:1125-7. [PMID: 7063845 DOI: 10.1126/science.7063845] [Citation(s) in RCA: 75] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A multineurotransmitter neuronal system that synthesizes and secretes both acetylated and deacetylated forms of alpha-melantropin and beta-endorphin is present in rat and human brain. The N-acetylated from of alpha-melanotropin had more potent behavioral effects than the deacetylated alpha-melanotropin. In the case of beta-endorphin, however, the deacetylated form has been shown to be more potent than the acetylated form. Enzymatic N-acetylation appears to be an important regulatory process for modulating the behavioral activity of peptides secreted from the opiomelanotropinergic multineurotransmitter neuron.
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O'Donohue TL, Chappell MC. Distribution of an enzyme which acetylates alpha-melanocyte stimulating hormone in rat brain and pituitary gland and effects of arcuate nucleus lesions. Peptides 1982; 3:69-75. [PMID: 7079192 DOI: 10.1016/0196-9781(82)90144-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
This study describes the distribution of an alpha-melanocyte stimulating hormone (alpha-MSH) acetyltransferase (MAT) in rat brain and pituitary gland. Highest activities of MAT were found in the neurointermediate lobe of the pituitary gland with the anterior lobe containing slightly less. Within the brain, lowest MAT activities were measured in the hypothalamus, the region which contained the highest concentrations of alpha-MSH. Relatively high enzyme activities of MAT were measured in the hippocampus, cortex and cerebellum--regions with very low alpha-MSH concentrations. The fact that MAT activity levels did not parallel alpha-MSH concentrations indicates that MAT was not solely localized to alpha-MSH synthesizing neurons or endocrine cells. Furthermore, arcuate nucleus lesions which depleted brain alpha-MSH failed to deplete MAT activity. Although MAT was not solely localized to alpha-MSH synthesizing cells, it may have functional significance for alpha-MSH acetylation due to compartmentalization with alpha-MSH in alpha-MSH synthesizing endocrine cells and neurons. Alternatively a second regionally specific MAT may exist.
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Martens GJ, Jenks BG, van Overbeeke AP. N alpha-acetylation is linked to alpha-MSH release from pars intermedia of the amphibian pituitary gland. Nature 1981; 294:558-60. [PMID: 6273748 DOI: 10.1038/294558a0] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Pease KA, Dixon JE. Characterization of N-alpha-acetylation of corticotropin fragments by a rat pituitary enzyme. Arch Biochem Biophys 1981; 212:177-85. [PMID: 6272651 DOI: 10.1016/0003-9861(81)90357-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Kido H, Vita A, Hannappel E, Horecker BL. Aminoterminal acetylation of synthetic N alpha-desacetyl thymosin alpha 1. Arch Biochem Biophys 1981; 208:95-100. [PMID: 7259192 DOI: 10.1016/0003-9861(81)90127-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Chrétien M, Seidah NG. Chemistry and biosynthesis of pro-opiomelanocortin. ACTH, MSH's, endorphins and their related peptides. Mol Cell Biochem 1981; 34:101-27. [PMID: 6262628 DOI: 10.1007/bf02354864] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Studies of lipotropins, melanotropins and endorphins on one hand, and of adrenocorticotropin on the other, has given rise to the concept of a multipotent precursor molecule recently renamed proopiomelanocortin. The preferential sites of cleavage of the precursor to produce its biologically active components are made of pairs of basic amino acid residues as described for the biosynthesis of beta-MSH and pro-insulin. Such structural feature is also found in other pro-hormone molecules. Pulse chase experiments and secretory studies carried out in both anterior and intermediate lobes of rat pituitary glands revealed the transformation of different forms of the precursor into different end-products, the anterior lobe producing preferentially ACTH and beta-LPH while the intermediate produces mainly the alpha-MSH and beta-endorphin. The multiple forms of precursors seem to differ in their carbohydrate content although at least two different gene products are still possible. The presence of similar peptides in the hypothalamus makes it highly probable that neuropeptides are biosynthesized with similar process. Thus the model of beta-LPH precursor, proposed as early as in 1967, is now applicable to the biosynthesis of all other neuropeptides. Major advances in this field are expected in the 1980s.
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O'Donohue TL, Handelmann GE, Chaconas T, Miller RL, Jacobowitz DM. Evidence that N-acetylation regulates the behavioral activity of alpha-MSH in the rat and human central nervous system. Peptides 1981; 2:333-44. [PMID: 7301640 DOI: 10.1016/s0196-9781(81)80126-x] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
alpha-MSH immunoreactive peptides were fractionated and characterized in rat and human brain and rat pituitary by reversed phase high pressure liquid chromatographic techniques. alpha-MSH and deacetylated alpha-MSH were two major naturally existing peptides in both brain and pituitary gland. Subsequent experiments examined the roles of these two peptides in neuronal function. The alpha-MSH was clearly more effective than deacetylated alpha-MSH in improving performance on a visual discrimination task after intraperitoneal administration and in inducing excessive grooming after intraventricular administration. The difference in behavioral potency may be explained by the fact that alpha-MSH was much more resistant to peptidase degradation than was deacetylated alpha-MSH. N-acetylation of alpha-MSH may be an effective regulatory process for modulating the behavioral potency of the secretory product of alpha-MSH-containing pituitary cells and neurons.
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Anderson CW, Lewis JB. Amino-terminal sequence of adenovirus type 2 proteins: hexon, fiber, component IX, and early protein 1B-15K. Virology 1980; 104:27-41. [PMID: 6985474 DOI: 10.1016/0042-6822(80)90363-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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