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Lagrutta LC, Layerenza JP, Bronsoms S, Trejo SA, Ves-Losada A. Nuclear-lipid-droplet proteome: carboxylesterase as a nuclear lipase involved in lipid-droplet homeostasis. Heliyon 2021; 7:e06539. [PMID: 33817385 PMCID: PMC8010399 DOI: 10.1016/j.heliyon.2021.e06539] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/11/2019] [Accepted: 03/12/2021] [Indexed: 11/20/2022] Open
Abstract
Nuclear-lipid droplets (nLD)—a dynamic cellular organelle that stores neutral lipids, within the nucleus of eukaryotic cells—consists of a hydrophobic triacylglycerol –cholesterol-ester core enriched in oleic acid (OA) surrounded by a monolayer of polar lipids, cholesterol, and proteins. nLD are probably involved in nuclear-lipid homeostasis serving as an endonuclear buffer that provides or incorporates lipids and proteins participating in signaling pathways, as transcription factors and enzymes of lipid metabolism and nuclear processes. In the present work, we analyzed the nLD proteome and hypothesized that nLD-monolayer proteins could be involved in processes similar as the ones occurring in the cLD including lipid metabolism and other cellular functions. We evaluated the rat-liver–nLD proteome under physiological and nonpathological conditions by GeLC-MS2. Since isolated nLD are highly diluted, a protein-concentrating isolation protocol was designed. Thirty-five proteins were identified within the functional categories: cytoskeleton and structural, transcription and translation, histones, protein-folding and posttranslational modification, cellular proliferation and/or cancer, lipid metabolism, and transport. Purified nLD contained an enzyme from the lipid-metabolism pathway, carboxylesterase 1d (Ces1d/Ces3). Nuclear Carboxylesterase localization was confirmed by Western blotting. By in-silico analyses rat Ces1d/Ces3 secondary and tertiary structure predicted would be equivalent to human CES1. These results—the first nLD proteome—demonstrate that a tandem-GeLC-MS2-analysis protocol facilitates studies like these on rat-liver nuclei. A diversity of cellular-protein function was identified indicating the direct or indirect nLD participation and involving Ces1d/Ces3 in the LD-population homeostasis.
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Affiliation(s)
- Lucía C. Lagrutta
- Instituto de Investigaciones Bioquímicas de La Plata “Profesor Doctor Rodolfo R. Brenner” (INIBIOLP-CCT-La Plata-CONICET-UNLP), La Plata, Argentina
| | - Juan P. Layerenza
- Instituto de Investigaciones Bioquímicas de La Plata “Profesor Doctor Rodolfo R. Brenner” (INIBIOLP-CCT-La Plata-CONICET-UNLP), La Plata, Argentina
| | - Silvia Bronsoms
- Servei de Proteómica i Biología Estructural de la Universitat Autonma de Barcelona, Barcelona, Spain
| | - Sebastián A. Trejo
- Servei de Proteómica i Biología Estructural de la Universitat Autonma de Barcelona, Barcelona, Spain
- Corresponding author.
| | - Ana Ves-Losada
- Instituto de Investigaciones Bioquímicas de La Plata “Profesor Doctor Rodolfo R. Brenner” (INIBIOLP-CCT-La Plata-CONICET-UNLP), La Plata, Argentina
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
- Corresponding author.
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Layerenza JP, González P, García de Bravo MM, Polo MP, Sisti MS, Ves-Losada A. Nuclear lipid droplets: a novel nuclear domain. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:327-40. [PMID: 23098923 DOI: 10.1016/j.bbalip.2012.10.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 10/02/2012] [Accepted: 10/16/2012] [Indexed: 10/27/2022]
Abstract
We investigated nuclear neutral-lipid (NL) composition and organization, as NL may represent an alternative source for providing fatty acids and cholesterol (C) to membranes, signaling paths, and transcription factors in the nucleus. We show here that nuclear NL were organized into nonpolar domains in the form of nuclear-lipid droplets (nLD). By fluorescent confocal microscopy, representative nLD were observed in situ within the nuclei of rat hepatocytes in vivo and HepG2 cells, maintained under standard conditions in culture, and within nuclei isolated from rat liver. nLD were resistant to Triton X-100 and became stained with Sudan Red, OsO4, and BODIPY493/503. nLD and control cytosolic-lipid droplets (cLD) were isolated from rat-liver nuclei and from homogenates, respectively, by sucrose-gradient sedimentation. Lipids were extracted, separated by thin-layer chromatography, and quantified. nLD were composed of 37% lipids and 63% proteins. The nLD lipid composition was as follows: 19% triacylglycerols (TAG), 39% cholesteryl esters, 27% C, and 15% polar lipids; whereas the cLD composition contained different proportions of these same lipid classes, in particular 91% TAG. The TAG fatty acids from both lipid droplets were enriched in oleic, linoleic, and palmitic acids. The TAG from the nLD corresponded to a small pool, whereas the TAG from the cLD constituted the main cellular pool (at about 100% yield from the total homogenate). In conclusion, nLD are a domain within the nucleus where NL are stored and organized and may be involved in nuclear lipid homeostasis.
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Affiliation(s)
- J P Layerenza
- INIBIOLP (CCT-La Plata-CONICET-UNLP), La Plata, Buenos Aires, Argentina
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Maté SM, Layerenza JP, Ves-Losada A. Arachidonic acid pools of rat kidney cell nuclei. Mol Cell Biochem 2010; 345:259-70. [DOI: 10.1007/s11010-010-0580-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 08/28/2010] [Indexed: 11/29/2022]
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Matunis MJ. Isolation and fractionation of rat liver nuclear envelopes and nuclear pore complexes. Methods 2006; 39:277-83. [PMID: 16870471 DOI: 10.1016/j.ymeth.2006.06.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Accepted: 06/13/2006] [Indexed: 01/08/2023] Open
Abstract
The nuclear envelope is a double lipid bilayer that physically separates the functions of the nucleus and the cytoplasm of eukaryotic cells. Regulated transport of molecules between the nucleus and the cytoplasm is essential for normal cell metabolism and is mediated by large protein complexes, termed nuclear pore complexes (NPCs), which span the inner and outer membranes of the nuclear envelope. Significant progress has been made in the past 10 years in identifying the protein composition of NPCs and the basic molecular mechanisms by which these complexes facilitate the selective exchange of molecules between the nucleus and the cytoplasm. However, many fundamentally important questions about the functions of NPCs, the specific functions of individual NPC-associated proteins, and the assembly and disassembly of NPCs, remain unanswered. This review describes approaches for isolating and characterizing nuclear envelopes and NPC-associated proteins from mammalian cells. It is anticipated that these procedures can be used as a starting point for further molecular and biochemical analysis of the mammalian nuclear envelope, NPCs, and NPC-associated proteins.
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Affiliation(s)
- Michael J Matunis
- Johns Hopkins University, Bloomberg School of Public Health, Department of Biochemistry and Molecular Biology, Baltimore MD 21205, USA.
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Maté SM, Brenner RR, Ves-Losada A. Phosphatidyl choline fatty acid remodeling in the hepatic cell nuclei. Prostaglandins Leukot Essent Fatty Acids 2004; 70:49-57. [PMID: 14643179 DOI: 10.1016/j.plefa.2003.08.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This study was performed to determine whether fatty acids incorporated into liver cell nuclei phosphatidylcholine (PtdCho) could be remodeled in the isolated nuclear. For this reason, rat liver cell nuclei were incubated in vitro with [1-14C]20:4n-6-CoA. PtdCho molecular species with the highest specific activity had an unsaturated fatty acid at sn-1 and sn-2 positions (20:4-20:4>18:2-20:4>18:1-20:4). 16:0-20:4 and 18:0-20:4 PtdChos showed a minor specific activity. When labeled nuclei were reincubated in the absence of labeled substrate with the addition of cytosol, ATP and CoA, the specific activity of 20:4-20:4, 18:2-20:4 and 18:1-20:4 species decreased, while that of 16:0-20:4 and 18:0-20:4 increased. In conclusion, the asymmetric fatty acid distribution of saturated fatty acids at sn-1 position, and unsaturated fatty acids at sn-2 position of nuclear PtdCho molecular species was re-established by an acyl-CoA-dependent remodeling process.
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Affiliation(s)
- S M Maté
- Facultad de Ciencias Médicas, Instituto de Investigaciones Bioquímicas de La Plata, UNLP-CONICET, calles 60 y 120, 1900 La Plata, Argentina
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Ves-Losada A, Maté SM, Brenner RR. Incorporation and distribution of saturated and unsaturated fatty acids into nuclear lipids of hepatic cells. Lipids 2001; 36:273-82. [PMID: 11337983 DOI: 10.1007/s11745-001-0718-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Liver nuclear incorporation of stearic (18:0), linoleic (18:2n-6), and arachidonic (20:4n-6) acids was studied by incubation in vitro of the [1-14C] fatty acids with nuclei, with or without the cytosol fraction at different times. The [1-14C] fatty acids were incorporated into the nuclei as free fatty acids in the following order: 18:0 > 20:4n-6 >> 18:2n-6, and esterified into nuclear lipids by an acyl-CoA pathway. All [1-14C] fatty acids were esterified mainly to phospholipids and triacylglycerols and in a minor proportion to diacylglycerols. Only [1-14C]18:2n-6-CoA was incorporated into cholesterol esters. The incorporation was not modified by cytosol addition. The incorporation of 20:4n-6 into nuclear phosphatidylcholine (PC) pools was also studied by incubation of liver nuclei in vitro with [1-14C]20:4n-6-CoA, and nuclear labeled PC molecular species were determined. From the 15 PC nuclear molecular species determined, five were labeled with [1-14C]20:4n-6-CoA: 18:0-20:4, 16:0-20:4, 18:1-20:4, 18:2-20:4, and 20:4-20:4. The highest specific radioactivity was found in 20:4-20:4 PC, which is a minor species. In conclusion, liver cell nuclei possess the necessary enzymes to incorporate exogenous saturated and unsaturated fatty acids into lipids by an acyl-CoA pathway, showing specificity for each fatty acid. Liver cell nuclei also utilize exogenous 20:4n-6-CoA to synthesize the major molecular species of PC with 20:4n-6 at the sn-2 position. However, the most actively synthesized is 20:4-20:4 PC, which is a quantitatively minor component. The labeling pattern of 20:4-20:4 PC would indicate that this molecular species is synthesized mainly by the de novo pathway.
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Affiliation(s)
- A Ves-Losada
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, UNLP-CONICET, La Plata, Argentina.
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Ves Losada A, Brenner RR. Incorporation of delta 5 desaturase substrate (dihomogammalinolenic acid, 20:3 n-6) and product (arachidonic acid 20:4 n-6) into rat liver cell nuclei. Prostaglandins Leukot Essent Fatty Acids 1998; 59:39-47. [PMID: 9758206 DOI: 10.1016/s0952-3278(98)90050-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The incorporation of [1-(14)C]20:3 n-6 and its desaturation product, [1-(14)C]20:4 n-6 into nuclear lipids from rat liver cells were investigated during in vitro delta5 desaturation. [1-(14)C]20:3 n-6 activated as 20:3 n-6-CoA by nuclear long chain acyl-CoA synthetase was: (1) incorporated into nuclear lipids mainly esterified to phospholipids and in a lesser proportion, to triglycerides and diglycerides; and (2) desaturated to 20:4 n-6-CoA by the nuclear delta5 desaturase. The amount of [1-(14)C]20:4 n-6 acid synthesized in cell nuclei increased along with time and was stimulated by the cytosol fraction. The major proportion of 20:4 n-6 was found in phospholipids and in a lesser proportion it remained as free fatty acids and was esterified to triglycerides and diglycerides. 20:4 n-6-CoA was incorporated into nuclear lipids and hydrolyzed to free fatty acid. These results indicate that liver cell nuclei possess the necessary enzymes to incorporate the delta5 desaturase substrate (20:3 n-6) as well as the product of desaturation (20:4 n-6) into nuclear TG, DG and PL following an acyl-CoA dependent pathway.
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Affiliation(s)
- A Ves Losada
- Dto de Cs. Biológicas, Facultad de Cs. Exactas, UNLP, Argentina.
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Ves-Losada A, Brenner RR. Long-chain fatty Acyl-CoA synthetase enzymatic activity in rat liver cell nuclei. Mol Cell Biochem 1996; 159:1-6. [PMID: 8813703 DOI: 10.1007/bf00226056] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A long-chain fatty acyl-CoA synthetase that catalyzes the activation of long-chain fatty acids as thioesters of CoA, was described in rat liver nuclei. This is the first step for further metabolization of fatty acids in the cell. Up to now, it has been shown that long-chain fatty acyl-CoA synthetase is located in the endoplasmic reticulum, in plasma membrane, in mitochondria and in peroxisomes. The nuclear long-chain fatty acyl-CoA synthetase was assayed using palmitic (16:0), linoleic (18:2n-6) and 8,11,14-eicosatrienoic (20:3n-6) acids as substrates and was stimulated linearly with nuclear protein concentration and with incubation time The higher enzymatic activity was observed with 18:2n-6 and 20:3n-6 acids as substrates. The synthesis of palmitoyl-CoA, linoleyl-CoA and 8,11,14-eicosatrienoyl-CoA followed normal Michaelis-Menten kinetics with respect to the corresponding substrate concentrations. The acyl-CoA synthetase seems to be saturated at a substrate concentration of 12.8 microM for all the acids tested. The apparent Km values decreased in the following order 20:3n-6 > 18:2n-6 > 16:0. The lowest apparent Km for palmitic acid indicates a preference for acylation of this acid in the cell nucleus.
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Affiliation(s)
- A Ves-Losada
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, UNLP-CONICET, Argentina
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9
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Christensen MJ, Cammack PM, Wray CD. Tissue specificity of selenoprotein gene expression in rats. J Nutr Biochem 1995; 6:367-372. [PMID: 12049997 DOI: 10.1016/0955-2863(95)80004-v] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To investigate the tissue-specific effects of inadequate, adequate, and high selenium intake on selenoprotein gene expression and enzyme activity, weanling rats were fed a selenium-deficient diet or the same diet supplemented with 0.1 or 2.0 mg of selenium/kg of diet for 91 days. No significant differences in growth were observed. In liver, transcription of genes for cellular glutathione peroxidase, type I iodothyronine 5'-deiodinase, and selenoprotein P was unaffected by selenium intake. Steady-state levels of mRNA for glutathione peroxidase and selenoprotein P were higher in liver than in kidney. For iodothyronine 5' deiodinase in the opposite was true. In liver, selenium deficiency reduced glutathione peroxidase mRNA by 89% and virtually abolished enzyme activity. For iodothyronine 5' deiodinase, mRNA and enzyme activity were reduced 69 and 70%, respectively. In kidney, selenium deprivation decreased glutathione peroxidase mRNA by 91% and reduced enzyme activity to nearly zero. For iodothyronine 5'-deiodinase, decreases in mRNA and enzyme activity were 19 and 62%, respectively. Reductions in selenoprotein P mRNA were 50% in kidney but only 14% in liver. The only difference in the effects between the two supplements was in liver, where iodothyronine 5'-deiodinase activity was reduced by increasing the selenium supplement above a nutritionally adequate level. Hence, for these selenoproteins, mRNA turnover appears to be the pretranslational process most sensitive to selenium intake. In addition, selenoprotein mRNAs are stabilized differentially in selenium deficiency, depending upon the tissue examined. Percentage changes in the activity of selenoenzymes were not always the same as the changes in their mRNA levels. This suggests that other processes, including translation and protein turnover, may determine the ultimate level of enzyme activity attained in response to dietary selenium intake.
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Abstract
Activity of one of the key enzymes involved in arachidonic acid (20:4 n-6) biosynthesis, the delta 5 desaturase, was found in rat liver cell nuclei. Up to now, it has been shown that the fatty acid desaturases are located exclusively in the endoplasmic reticulum. Similarly to what happens with microsomal enzyme the nuclear delta 5 desaturase enzyme was only fully active in the presence of a cytosolic factor. In this condition it reached a specific activity of 50 pmol 20:4 n-6 formed/min/mg of protein. This fact would imply that purified nuclei like purified microsomes lack a soluble cytosol factor necessary for the total desaturation reaction expression. Besides the nuclear delta 5 desaturase has an optimal pH of 7.6 and is inhibited by 1 or 10 mM KCN. Low long chain acyl-CoA synthetase activity that catalyzes the formation of 20:3 n-6-CoA, was also found in liver nuclei. This step would be essential in nuclear desaturation since when ATP and/or CoA (necessary for the acylation reaction) are omitted from the incubation mixture, the desaturation reaction does not take place.
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Affiliation(s)
- A Ves-Losada
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Facultad de Ciencias Médicas, UNLP-CONICET, Argentina
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11
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Pacifici GM, Viani A. Methods of determining plasma and tissue binding of drugs. Pharmacokinetic consequences. Clin Pharmacokinet 1992; 23:449-68. [PMID: 1458763 DOI: 10.2165/00003088-199223060-00005] [Citation(s) in RCA: 174] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The available techniques for the investigation of drug binding to plasma and tissues protein are reviewed and the advantages and disadvantages of the various techniques stated. A comparison of different plasma protein binding techniques is made which shows that the size of the unbound fraction of drug may be influenced by the method used. Protein binding may be assayed by methods including equilibrium dialysis, ultrafiltration, ultracentrifugation, gel filtration, binding to albumin microspheres and circular dichroism. Tissue binding techniques can involve testing binding to isolated organs, tissue slices, homogenates and isolated subcellular particles. Details of the available methods to compute pharmacokinetic constants are given. Stereoselective binding has been investigated for a limited number of drugs and the difference in the binding of 2 enantiomers is usually modest. The measurement of the binding constants is often required to characterise the drug-protein interaction. Mathematical and graphical methods to compute the pharmacokinetic parameters are discussed. The implications of binding on the volume of distribution and clearance of drugs are examined.
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Affiliation(s)
- G M Pacifici
- Department of Biomedicine, University of Pisa Medical School, Italy
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12
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The electrical properties of the nuclear envelope, and their possible role in the regulation of eukaryotic gene expression. J Electroanal Chem (Lausanne) 1991. [DOI: 10.1016/0022-0728(91)85652-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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The electrical properties of the nuclear envelope, and their possible role in the regulation of eukaryotic gene expression. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/0302-4598(91)80002-k] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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14
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Sheehan JE, Pitot HC, Kasper CB. Transcriptional regulation and localization of the tissue-specific induction of epoxide hydrolase by lead acetate in rat kidney. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(19)67763-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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15
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Matzke MA, Varga F, Berger H, Schernthaner J, Schweizer D, Mayr B, Matzke AJ. A 41-42 bp tandemly repeated sequence isolated from nuclear envelopes of chicken erythrocytes is located predominantly on microchromosomes. Chromosoma 1990; 99:131-7. [PMID: 2357914 DOI: 10.1007/bf01735329] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To study whether specific DNA sequences are associated with nuclear membranes, residual DNA was extracted from DNase-treated nuclear envelopes prepared from erythrocytes of adult chickens (Gallus domesticus). This DNA was then blunt-end ligated into a bacterial plasmid vector. DNA blot analysis and nucleotide sequence determination revealed that approximately 30% of the cloned fragments consisted of different multiples of a 41-42 bp tandemly repeated, partially symmetrical sequence. In situ hybridization to chicken chromosomes demonstrated that the sequence was located primarily on microchromosomes, although some hybridization was also observed to macrochromosomes 7 and 8. Digestion of chicken DNA with any of a number of restriction enzymes did not completely reduce the intensity of a high molecular weight band to which the repeated sequence hybridized. These results, along with those obtained from in situ hybridization, suggested that many copies of this sequence are organized into large tandem arrays, and are not dispersed in many shorter repetitive blocks throughout the chicken genome. Although the repetitive sequence constituted approximately 10% of the chicken genome, it did not hybridize to quail or turkey DNA.
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Affiliation(s)
- M A Matzke
- Institute of Molecular Biology, Austrian Academy of Sciences, Salzburg
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16
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Vaca CE, Harms-Ringdahl M. Interaction of lipid peroxidation products with nuclear macromolecules. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 1001:35-43. [PMID: 2912492 DOI: 10.1016/0005-2760(89)90304-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The interaction of lipid peroxidation products with nuclear macromolecules was investigated in rat liver nuclei labelled with [3H]arachidonic acid. Lipid peroxidation reactions were driven both non-enzymatically and enzymatically by the addition of ascorbate-Fe2+ or NADPH-ADP-Fe3+, respectively, to the incubation mixtures. The extent of peroxidation was evaluated by the formation of thiobarbituric acid chromophore and of radioactive hydrophilic peroxidation products. The results obtained show that: (1) nuclear membrane lipid peroxidation products formed during incubation interact with DNA and total nuclear proteins; (2) non-enzymatic lipid peroxidation processes induced a 40% larger association of peroxidation products to DNA compared to processes driven enzymatically, whereas the corresponding interaction with total nuclear proteins was similar in both peroxidation systems; (3) the radioactivity associated with histones decreased during incubation in the presence of ascorbate-Fe2+ or NADPH-ADP-Fe3+, and increased in control samples (no additions); (4) inhibition of lipid peroxidation by the iron chelator Desferrioxamine B prevented the association of peroxidation products to nuclear macromolecules; (5) the levels of radioactivity found in DNA after 180 min of incubation would represent the formation of 0.6-1.0 adducts per 10(6) DNA bases. The results obtained provide evidence for an interaction between lipid peroxidation products and chromatin in the interior of the cell nucleus.
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Affiliation(s)
- C E Vaca
- Department of Radiobiology, Arrhenius Laboratories for Natural Sciences, University of Stockholm, Sweden
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18
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Induction of the hepatic mixed-function oxidase system by synthetic glucocorticoids. Transcriptional and post-transcriptional regulation. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(19)75930-4] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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19
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Lotlikar PD, Clearfield MS, Jhee EC. Effect of butylated hydroxyanisole on in vivo and in vitro hepatic aflatoxin B1-DNA binding in rats. Cancer Lett 1984; 24:241-50. [PMID: 6437665 DOI: 10.1016/0304-3835(84)90019-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Butylated hydroxyanisole (BHA) pretreatment of male rats has been examined for its effect on in vivo and in vitro hepatic aflatoxin B1-DNA binding (AFB1-DNA) in these animals. No difference either in cytochrome P-450 content or microsome-mediated AFB1-DNA was observed between livers from control and treated rats. However, cytosols from treated animals showed severalfold more inhibition of microsome mediated AFB1 binding to either exogenous or endogenous DNA than cytosols from controls. Presence of 1 mM level of either trichloropropene oxide or styrene oxide partially reversed the cytosolic inhibition of binding. Intraperitoneal administration of AFB1 2h before killing produced 50% less AFB1 binding to nuclear DNA in treated than in control animals. The role of induced glutathione S-transferases in treated rats in modulating hepatic AFB1-DNA binding is discussed.
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20
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Smith CD, Wells WW. Phosphorylation of rat liver nuclear envelopes. I. Characterization of in vitro protein phosphorylation. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(17)44676-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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21
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Simmons DL, Kasper CB. Genetic polymorphisms for a phenobarbital-inducible cytochrome P-450 map to the Coh locus in mice. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(17)44531-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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22
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Smith CD, Wells WW. Phosphorylation of rat liver nuclear envelopes. II. Characterization of in vitro lipid phosphorylation. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(17)44677-1] [Citation(s) in RCA: 103] [Impact Index Per Article: 2.5] [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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Risinger MA, Larsen WJ. Interaction of filipin with junctional membrane at different stages of the junction's life history. Tissue Cell 1983; 15:1-15. [PMID: 6407147 DOI: 10.1016/0040-8166(83)90029-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The relationship of filipin-sterol complexes to tight and gap junctions during their formation, maturation, internalization, and degradation was studied in separate cell lines. Filipin-sterol complexes tended to be excluded from mature junctions in tight junction forming COLO 316 cells and gap junction forming SW-13 cells. Once internalized, unlabeled junctional membrane appeared to fuse with heavily labeled vesicles, presumably lysosomes. Although the absence of filipin-sterol complexes from junctional membrane does not necessarily reflect the absolute sterol content of this membrane, the fact that filipin-sterol complexes are largely excluded from these areas indicates that this membrane is different from surrounding membrane. The absence of filipin-sterol complexes also permits the visualization of 'mixing' of this specialized unlabeled membrane domain with other filipin labeled membrane systems.
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24
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Sum CY, Kasper CB. Mixed-function amine oxidase of the rat hepatocyte nuclear envelope. Demonstration and effects of phenobarbital and 3-methylcholanthrene. Biochem Pharmacol 1982; 31:69-73. [PMID: 7059354 DOI: 10.1016/0006-2952(82)90238-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Mixed-function amine oxidase (EC 1.14.13.8) has been demonstrated in highly purified rat hepatocyte nuclear envelope . The enzyme was present in the nuclear envelope at a level 20 percent of that observed in microsomes. Induction studies indicated that nuclear envelope amine oxidase as well as its microsomal counterpart were refractory to the effects of phenobarbital and 3-methylcholanthrene. Phenobarbital administration increased the specific activity of the microsomal N, N-dimethylaniline N-demethylase and benzo[a]pyrene hydroxylase by 600 and 190 percent, respectively, but decreased the specific activity of the nuclear enzymes by 30-50 percent. In contrast, 3-methylcholanthrene increased the specific activity of benzo[a]pyrene hydroxylase in nuclear envelope and microsomes by 42- and 11-fold, respectively. The hydrocarbon also increased the microsomal and nuclear N, N-dimethylaniline N-demethylase by 40 and 60 percent, respectively, but the specific activity of microsomal and nuclear aniline 4-hydroxylase was decreased by 50 percent. Demonstration of amine oxidase in rat hepatocyte nuclear envelope implicates this enzyme in the toxicity and carcinogenicity of certain drugs and chemicals.
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Yang CS, Sydor W, Martin MB, Lewis KF. Effects of butylated hydroxyanisole on the aryl hydrocarbon hydroxylase of rats and mice. Chem Biol Interact 1981; 37:337-50. [PMID: 6271406 DOI: 10.1016/0009-2797(81)90119-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Veneziale CM, Utz ME, Steer RC, Wilson MJ, Ahmed K. Nuclear envelope of the seminal-vesicle epithelium. Biochem J 1981; 198:259-64. [PMID: 6275843 PMCID: PMC1163243 DOI: 10.1042/bj1980259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The nuclear envelope of seminal-vesicle epithelium was isolated by a procedure involving enzymic digestion with deoxyribonuclease I, sonication in the presence of 0.34 M-sodium citrate, and centrifugation through sucrose density gradients. The mass of envelope DNA was only 0.8% of that of envelope protein, and by transmission electron microscopy the envelope was 98-99% pure. We showed that the envelope possess a protein kinase activity which is uninfluenced by cyclic nucleotides. Both lysine-rich histone and dephosphophosvitin as substrates gave a greater specific activity than did envelope protein itself. Optimum requirements with respect to Na+, Mg2+, pH and ATP were established for each substrate, and the influence of other factors on enzyme activity was investigated. Data, obtained mainly with the use of lysine-rich histone, are presented which indicate that nuclear envelope from intact and 96 h-castrated guinea pigs may have equal protein kinase activities and, in separate experiments, equal phosphoprotein phosphatase activities. Clarification of these initial observations must await identification of the natural substrates or the envelope's phosphorylation-dephosphorylation reactions.
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Parikh I, Anderson W, Neame P. Identification of high affinity estrogen binding sites in calf uterine microsomal membranes. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)70459-1] [Citation(s) in RCA: 26] [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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Carlisle TL, Suttie JW. Vitamin K dependent carboxylase: subcellular location of the carboxylase and enzymes involved in vitamin K metabolism in rat liver. Biochemistry 1980; 19:1161-7. [PMID: 6245680 DOI: 10.1021/bi00547a019] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Vitamin K dependent carboxylation of an exogenous peptide substrate and endogenous protein substrates, vitamin K epoxidation, and reduction of vitamin K epoxide were measured in subcellular fractions from rat liver. The rough microsomal fraction was highly enriched in all four activities; lower levels were found in smooth microsomes. Mitochondria, nuclei, and cytosol had negligible activities. The addition of 0.2% Triton X-100 to intact microsomes resulted in a 10-20-fold stimulation in carboxylation of a peptide substrate. This marked latency suggests that the active site of the carboxylase may be accessible only from the lumen of the microsomal membrane. A lumen-facing orientation of the carboxylase was also supported by its inaccessibility to trypsin in intact microsomes contrasted with marked inhibition by trypsin in detergent-permeabilized microsomes. Vitamin K epoxidase and epoxide reductase activities were also inhibited by trypsin much more effectively in permeabilized than in intact microsomes, although some degree of exposure at the cytosolic surface was also indicated. These data suggest that carboxylation is an early event in prothrombin synthesis occurring primarily on the lumen side of the rough endoplasmic reticulum membrane. The location of the vitamin K epoxidation-reduction cycle enzymes is consistent with their possible role in the carboxylation reaction.
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Friedberg T, Bentley P, Stasiecki P, Glatt H, Raphael D, Oesch F. The identification, solubilization, and characterization of microsome-associated glutathione S-transferases. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(19)86422-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Lam K, Kasper C. Electrophoretic analysis of three major nuclear envelope polypeptides. Topological relationship and sequence homology. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(19)86541-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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31
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The binding of cytochrome b5 to phospholipid vesicles and biological membranes. Effect of orientation on intermembrane transfer and digestion by carboxypeptidase Y. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(18)50393-8] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Rao CV, Mitra S. Gonadotropin and prostaglandins binding sites in nuclei of bovine corpora lutea. Biochim Biophys Acta Gen Subj 1979; 584:454-66. [PMID: 222342 DOI: 10.1016/0304-4165(79)90119-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Highly purified nuclei isolated from bovine corpora lutea showed marked enrichment of NAD pyrophosphorylase, a marker for this organelle. Rough endoplasmic reticulum and lysosomal markers were undetectable, whereas plasma membrane and Golgi markers were detectable but not enriched in nuclei. These highly puridied nuclei exhibited specific binding with 125I-labeled human choriogonadotropin, [3H]prostaglandin E1 and [3H]prostaglandin F2 alpha. However, these bindings were only 15.4% (human choriogonadotropin), 7.9% (prostaglandin E1) and 8.9% (prostaglandin F2 alpha) of the plasma membrane binding observed under the same conditions. Washing of nuclei and plasma membranes twice with buffer containing 0.1% Triton X-100 resulted in gonadotropin and prostaglandin F2 alpha binding site and 5'-nucleotidase (EC 3.1.3.5) losses from nuclei that were different from those observed for plasma membranes. More importantly, the washed nuclei exhibited 44% (human choriogonadotropin), 21--26% (prostaglandins) of original specific binding despite virtual disappearance of 5'-nucleotidase activity. The nuclear membranes isolated from nuclei, specifically bound 125I-labeled human choriogonadotropin and [3H]prostaglandin F2 alpha to the same extent or significantly more ([3H]prostaglandin E1, P less than 0.05) than nuclei themselves, despite the marked losses of chromatin. In summary, our data suggest that gonadotropin and prostaglandins bind to nuclei and that this binding was intrinsic and was primarily associated with the nuclear membrane.
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Elias PM, Goerke J, Friend DS, Brown BE. Freeze-fracture identification of sterol-digitonin complexes in cell and liposome membranes. J Cell Biol 1978; 78:577-96. [PMID: 690180 PMCID: PMC2110113 DOI: 10.1083/jcb.78.2.577] [Citation(s) in RCA: 129] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
To advance our understanding of the organization of cholesterol within cell membranes, we used digitonin in freeze-fracture investigations of model lipid vesicles and tissues. Cholesterol suspensions or multilamellar liposomes composed of phosphatidylcholine with and without cholesterol were exposed to digitonin. Freeze-fracture replicas of those multilamellar liposomes containing cholesterol displayed either 50--60-nm wide intramembrane corrugations or extramembrane tubular complexes. Comparable intramembrane hemitubular scallops and extra-cellular free tubular complexes were observed in thin sections. Exposure of sperm, erythrocytes (whole and ghosts), and intact tissues (skin, liver, adrenal gland, epididymis) to digitonin produced the same types of intra- and extramembrane complexes or furrows as were formed in liposomes. The plasma membrane of guinea pig serum tail had two unfurrowed regions: the annulus and the zipper. Incubating erythrocyte membranes with digitonin resulted in rapid displacement of cholesterol, accompanied by intramembrane particle clustering and membrane faceting, a feature which we did not see in the intact epithelia studied. In freeze-fractured epithelia, we found that plasma membranes, lysosomes, and some vesicular organelles commonly furrowed, but that mitochondrial membranes and nuclear envelopes were generally spared, correlating well with their known cholesterol content. Finally, plasma membrane corrugations approached but did not impinge on either gap or tight junctions, or on coated vesicles. We conclude that freeze-fracture of membranes exposed to digitonin: (a) reveals distinctive cholesterol-digitonin structural complexes; (b) distinguishes cholesterol-rich and -poor organelle membranes; and (c) demonstrates membrane domains rich or poor in cholesterol.
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Fahl W, Jefcoate C, Kasper C. Characteristics of benzo(a)pyrene metabolism and cytochrome P-450 heterogeneity in rat liver nuclear envelope and comparison to microsomal membrane. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)40809-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Vigneri R, Goldfine I, Wong K, Smith G, Pezzino V. The nuclear envelope. The major site of insulin binding in rat liver nuclei. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)38045-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Ronzio RA, Kronquist KE, Lewis DS, MacDonald RJ, Mohrlok SH, O'Donnell JJ. Glycoprotein synthesis in the adult rat pancreas. IV. Subcellular distribution of membrane glycoproteins. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 508:65-84. [PMID: 629968 DOI: 10.1016/0005-2736(78)90189-x] [Citation(s) in RCA: 69] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Zymogen granule membranes from the rat exocrine pancreas displays distinctive, simple protein and glycoprotein compositions when compared to other intracellular membranes. The carbohydrate content of zymogen granule membrane protein was 5-10-fold greater than that of membrane fractions isolated from smooth and rough microsomes, mitochondria and a preparation containing plasma membranes, and 50-100-fold greater than the zymogen granule content and the postmicrosomal supernate. The granule membrane glycoprotein contained primarily sialic acid, fucose, mannose, galactose and N-acetylglucosamine. The levels of galactose, fucose and sialic acid increased in membranes in the following order: rough microsomes less than smooth microsomes less than zymogen granules. Membrane polypeptides were analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The profile of zymogen granule membrane polypeptides was characterized by GP-2, a species with an apparent molecular weight of 74 000. Radioactivity profiles of membranes labeled with [3H]glucosamine or [3H]leucine, as well as periodic acid-Schiff stain profiles, indicated that GP-2 accounted for approx. 40% of the firmly bound granule membrane protein. Low levels of a species similar to GP-2 were detected in membranes of smooth microsomes and the preparation enriched in plasma membranes but not in other subcellular fractions. These results suggest that GP-2 is a biochemical marker for zymogen granules. Membrane glycoproteins of intact zymogen granules were resistant to neuraminidase treatment, while those in isolated granule membranes were readily degraded by neuraminidase. GP-2 of intact granules was not labeled by exposure to galactose oxidase followed by reduction with NaB3H4. In contrast, GP-2 in purified granule membranes was readily labeled by this procedure. Therefore GP-2 appears to be located on the zymogen granule interior.
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