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Iommarini L, Ghelli A, Tropeano CV, Kurelac I, Leone G, Vidoni S, Lombes A, Zeviani M, Gasparre G, Porcelli AM. Unravelling the Effects of the Mutation m.3571insC/MT-ND1 on Respiratory Complexes Structural Organization. Int J Mol Sci 2018. [PMID: 29518970 PMCID: PMC5877625 DOI: 10.3390/ijms19030764] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mammalian respiratory complex I (CI) biogenesis requires both nuclear and mitochondria-encoded proteins and is mostly organized in respiratory supercomplexes. Among the CI proteins encoded by the mitochondrial DNA, NADH-ubiquinone oxidoreductase chain 1 (ND1) is a core subunit, evolutionary conserved from bacteria to mammals. Recently, ND1 has been recognized as a pivotal subunit in maintaining the structural and functional interaction among the hydrophilic and hydrophobic CI arms. A critical role of human ND1 both in CI biogenesis and in the dynamic organization of supercomplexes has been depicted, although the proof of concept is still missing and the critical amount of ND1 protein necessary for a proper assembly of both CI and supercomplexes is not defined. By exploiting a unique model in which human ND1 is allotopically re-expressed in cells lacking the endogenous protein, we demonstrated that the lack of this protein induces a stall in the multi-step process of CI biogenesis, as well as the alteration of supramolecular organization of respiratory complexes. We also defined a mutation threshold for the m.3571insC truncative mutation in mitochondrially encoded NADH:ubiquinone oxidoreductase core subunit 1 (MT-ND1), below which CI and its supramolecular organization is recovered, strengthening the notion that a certain amount of human ND1 is required for CI and supercomplexes biogenesis.
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Affiliation(s)
- Luisa Iommarini
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Via Francesco Selmi 3, 40126 Bologna, Italy.
| | - Anna Ghelli
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Via Francesco Selmi 3, 40126 Bologna, Italy.
| | - Concetta Valentina Tropeano
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Via Francesco Selmi 3, 40126 Bologna, Italy.
| | - Ivana Kurelac
- Dipartimento Scienze Mediche e Chirurgiche (DIMEC), U.O. Genetica Medica, Pol. Universitario S. Orsola-Malpighi, Università di Bologna, via Massarenti 9, 40138 Bologna, Italy.
| | - Giulia Leone
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Via Francesco Selmi 3, 40126 Bologna, Italy.
| | - Sara Vidoni
- Medical Research Council, Mitochondrial Biology Unit, Cambridge CB2 0XY, UK.
| | - Anne Lombes
- Inserm U1016, Institut Cochin, F-75014 Paris, France.
| | - Massimo Zeviani
- Medical Research Council, Mitochondrial Biology Unit, Cambridge CB2 0XY, UK.
| | - Giuseppe Gasparre
- Dipartimento Scienze Mediche e Chirurgiche (DIMEC), U.O. Genetica Medica, Pol. Universitario S. Orsola-Malpighi, Università di Bologna, via Massarenti 9, 40138 Bologna, Italy.
| | - Anna Maria Porcelli
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Via Francesco Selmi 3, 40126 Bologna, Italy.
- Centro Interdipartimentale di Ricerca Industriale Scienze della Vita e Tecnologie per la Salute, Università di Bologna, 40100 Bologna, Italy.
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Shin J, Lee SH, Kwon MC, Yang DK, Seo HR, Kim J, Kim YY, Im SK, Abel ED, Kim KT, Park WJ, Kong YY. Cardiomyocyte specific deletion of Crif1 causes mitochondrial cardiomyopathy in mice. PLoS One 2013; 8:e53577. [PMID: 23308255 PMCID: PMC3537664 DOI: 10.1371/journal.pone.0053577] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 12/03/2012] [Indexed: 11/25/2022] Open
Abstract
Mitochondria are key organelles dedicated to energy production. Crif1, which interacts with the large subunit of the mitochondrial ribosome, is indispensable for the mitochondrial translation and membrane insertion of respiratory subunits. To explore the physiological function of Crif1 in the heart, Crif1(f/f) mice were crossed with Myh6-cre/Esr1 transgenic mice, which harbor cardiomyocyte-specific Cre activity in a tamoxifen-dependent manner. The tamoxifen injections were given at six weeks postnatal, and the mutant mice survived only five months due to hypertrophic heart failure. In the mutant cardiac muscles, mitochondrial mass dramatically increased, while the inner structure was altered with lack of cristae. Mutant cardiac muscles showed decreased rates of oxygen consumption and ATP production, suggesting that Crif1 plays a critical role in the maintenance of both mitochondrial structure and respiration in cardiac muscles.
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Affiliation(s)
- Juhee Shin
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul, Republic of Korea
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, Republic of Korea
| | - Seok Hong Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Chung-Ang University, Dongjak-gu, Seoul, Republic of Korea
| | - Min-Chul Kwon
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul, Republic of Korea
| | - Dong Kwon Yang
- Global Research Laboratory and Department of Life Science, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Ha-Rim Seo
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul, Republic of Korea
| | - Jaetaek Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Chung-Ang University, Dongjak-gu, Seoul, Republic of Korea
| | - Yoon-Young Kim
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul, Republic of Korea
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, Republic of Korea
| | - Sun-Kyoung Im
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul, Republic of Korea
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, Republic of Korea
| | - Evan Dale Abel
- Program in Molecular Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Kyong-Tai Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, Republic of Korea
| | - Woo Jin Park
- Global Research Laboratory and Department of Life Science, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Young-Yun Kong
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul, Republic of Korea
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Kao LP, Ovchinnikov D, Wolvetang E. The effect of ethidium bromide and chloramphenicol on mitochondrial biogenesis in primary human fibroblasts. Toxicol Appl Pharmacol 2012; 261:42-9. [DOI: 10.1016/j.taap.2012.03.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ramachandran A, Ceaser E, Darley-Usmar VM. Chronic exposure to nitric oxide alters the free iron pool in endothelial cells: role of mitochondrial respiratory complexes and heat shock proteins. Proc Natl Acad Sci U S A 2003; 101:384-9. [PMID: 14691259 PMCID: PMC314194 DOI: 10.1073/pnas.0304653101] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The mechanisms of nitric oxide (NO) signaling include binding to the iron centers in soluble guanylate cyclase and cytochrome c oxidase and posttranslational modification of proteins by S-nitrosation. Low levels of NO control mitochondrial number in cells, but little is known of the impact of chronic exposure to high levels of NO on mitochondrial function in endothelial cells. The focus of this study is the interaction of NO with mitochondrial respiratory complexes in cell culture and the effect this has on iron homeostasis. We demonstrate that chronic exposure of endothelial cells to NO decreased activity and protein levels of complexes I, II, and IV, whereas citrate synthase and ATP synthase were unaffected. Inhibition of these respiratory complexes was accompanied by an increase in cellular S-nitrosothiol levels, modification of cysteines residues, and an increase in the labile iron pool. The NO-dependent increase in the free iron pool and inhibition of complex II was prevented by inhibition of mitochondrial protein synthesis, consistent with a major contribution of the organelle to iron homeostasis. In addition, inhibition of mitochondrial protein synthesis was associated with an increase in heat shock protein 60 levels, which may be an additional mechanism leading to preservation of complex II activity.
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Affiliation(s)
- Anup Ramachandran
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Ramachandran A, Moellering DR, Ceaser E, Shiva S, Xu J, Darley-Usmar V. Inhibition of mitochondrial protein synthesis results in increased endothelial cell susceptibility to nitric oxide-induced apoptosis. Proc Natl Acad Sci U S A 2002; 99:6643-8. [PMID: 12011428 PMCID: PMC124456 DOI: 10.1073/pnas.102019899] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mutations in mitochondrial DNA, affecting the activity of respiratory complexes, have been implicated in many chronic degenerative diseases. Mitochondrial proteins coded for by both the mitochondrial and nuclear genes are known to have important signaling roles in apoptosis. However, the impact of the inhibition of mitochondrial protein synthesis on apoptosis is largely unknown. This inhibition is particularly important in NO-dependent cytotoxicity, which is believed to have a significant mitochondrial component and depend on other factors such as glycolysis. In this study we have examined whether the inhibition of mitochondrial protein synthesis by chloramphenicol increases the susceptibility of endothelial cells to undergo NO-dependent apoptosis in glucose-free media. Bovine aortic endothelial cells were treated with chloramphenicol, which resulted in a decreased ratio of mitochondrial complex IV to cytochrome c and increased oxidant production in the cell. Inhibition of mitochondrial protein synthesis was associated with a greater susceptibility of the cells to apoptosis induced by NO in glucose-free medium.
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Affiliation(s)
- Anup Ramachandran
- Department of Pathology, University of Alabama, Birmingham, AL 35294, USA
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Abstract
CDP-diacylglycerol for polyglycerophosphatide biogenesis can be synthesized within rat liver mitochondria. This membrane-associated enzyme was predominantly located in the inner mitochondrial membrane. GTP had a significant effect in activating the microsomal CDP-diacylglycerol synthase, especially if the microsomes were preincubated with GTP in the presence of phosphatidic acid. This stimulatory effect of GTP on the microsomal enzyme was not detected in the mitochondrial fractions. The enzymes could be solubilized from the membrane fractions using CHAPS, and the detergent-soluble activity partially restored by addition of phospholipids. Mitochondrial and microsomal CDP-diacylglycerol synthase activity could be completely separated by anion-exchange column chromatography. The mitochondrial and microsomal CDP-diacylglycerol synthases appear to be two distinct enzymes with different localization and regulatory characteristics.
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Affiliation(s)
- A Y Mok
- University of Western Ontario, Department of Biochemistry, London, Canada
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Mangiapane EH. The effect of adriamycin on glycerolphosphate acyltransferase and lipid metabolism in rat hepatocytes in monolayer culture. Biochem Pharmacol 1990; 40:1577-82. [PMID: 2222513 DOI: 10.1016/0006-2952(90)90457-v] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Total and mitochondrial glycerolphosphate acyltransferase activities were measured after 24 hr exposure of rat hepatocytes to Adriamycin. Both activities decreased with increasing concentrations of Adriamycin. The activity of the microsomal glycerolphosphate acyltransferase, which was determined from the difference between the total and mitochondrial enzyme activity, also decreased with increasing drug concentration. The effect on glycerolphosphate acyltransferase was specific as there was no change in lactate dehydrogenase or cytochrome oxidase activity in this time period. Adriamycin did not inhibit mitochondrial glycerolphosphate acyltransferase activity in vitro. After 24 hr exposure of hepatocytes to Adriamycin no change was observed in the biosynthesis of phosphatidylcholine or triacylglycerol. Secretion of lipid into the medium was measured over the subsequent 24 hr. There was a significant reduction in very low density lipoprotein secretion as measured by triacylglycerol secretion from cells incubated with 5 microM Adriamycin. Cells were damaged by the 48 hr exposure to 1 microM and higher concentrations of Adriamycin as evidenced by a fall in lactate dehydrogenase activity in these cells. The secretion of lysophosphatidylcholine, as measured by the incorporation of [3H]glycerol into medium lysophosphatidylcholine, was significantly increased when cells were incubated with 5 microM Adriamycin. The results are discussed in relation to the effect of Adriamycin on hepatic lipid metabolism and the cardiotoxicity of the drug.
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Affiliation(s)
- E H Mangiapane
- Department of Biochemistry, University of Nottingham Medical School, Queen's Medical Centre, U.K
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Ebringer L. Interaction of drugs with extranuclear genetic elements and its consequences. TERATOGENESIS, CARCINOGENESIS, AND MUTAGENESIS 1990; 10:477-501. [PMID: 1982911 DOI: 10.1002/tcm.1770100606] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacterial ancestry of mitochondria and plastids is now generally accepted. Both organelles contain their own DNA and transcription-translation apparatus of a prokaryotic type. Due to this fact these systems carry bacteria-like properties. Thus organellar DNA and ribosomes are essentially different from nuclear DNA and cytoplasmic ribosomes in physical as well as in functional respects. Due to the bacterial character of both types of organelles they are susceptible to various antibacterial chemicals. Inhibitors of bacterial protein synthesis inhibit mitochondrial (plastidial) biogenesis. Therefore the cellular content of mitochondria (plastids)-made proteins decreases during cytoplasmic turnover or cell division in the presence of these drugs. Such drug activity consequently leads to a reduced capacity for oxidative phosphorylation or photosynthesis. Organellar genomes are less stable and more sensitive to mutagenesis as compared to nuclear genome. It means also that genotoxic agents induce various disorders of mitochondrial (plastidial) functions. Impairments in the respiratory chain are associated with structural as well as functional abnormalities of mitochondria. These are clinically expressed mostly in tissues with a high demand for ATP: brain, heart, skeletal muscle, and retina. On the other hand, some antibacterial inhibitors of mitochondrial biogenesis (e.g., tetracyclines) inhibit selectively tumor cell proliferation. Therefore they may be considered for use in anticancer therapy. The article summarizes the response of mitochondria and plastids in various organisms to drugs and environmental xenobiotics. Various model organisms suitable for detection of xenobiotic effect on mitochondria (plastids) are presented as well as the possible consequences of such interaction.
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Affiliation(s)
- L Ebringer
- Institute of Molecular and Subcellular Biology, Comenius University, Bratislava, Czechoslovakia
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Cino M, Del Maestro RF. Generation of hydrogen peroxide by brain mitochondria: the effect of reoxygenation following postdecapitative ischemia. Arch Biochem Biophys 1989; 269:623-38. [PMID: 2919886 DOI: 10.1016/0003-9861(89)90148-3] [Citation(s) in RCA: 118] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The hypothesis that mitochondria damaged during complete cerebral ischemia generate increased amounts of superoxide anion radical and hydrogen peroxide (H2O2) upon postischemic reoxygenation has been tested. In rat brain mitochondria, succinate supported H2O2 generation, whereas NADH-linked substrates, malate plus glutamate, did so only in the presence of respiratory chain inhibitors. Succinate-supported H2O2 generation was diminished by rotenone and the uncoupler carbonyl cyanide m-chlorphenylhydrazone and enhanced by antimycin A and increased oxygen tensions. When maximally reduced, the NADH dehydrogenase and the ubiquinone-cytochrome b regions of the electron transport chain are sources of H2O2. These studies suggest that a significant portion of H2O2 generation in brain mitochondria proceeds via the transfer of reducing equivalents from ubiquinone to the NADH dehydrogenase portion of the electron transport chain. Succinate-supported H2O2 generation by mitochondria isolated from rat brain exposed to 15 min of postdecapitative ischemia was 90% lower than that of control preparations. The effect of varying oxygen tensions on H2O2 generation by postischemic mitochondrial preparations was negligible compared with the increased H2O2 generation measured in control preparations. Comparison of the effects of respiratory chain inhibitors and oxygen tension on succinate-supported H2O2 generation suggests that the ability for reversed electron transfer is impaired during ischemia. These data do not support the hypothesis that mitochondrial free radical generation increases during postischemic reoxygenation.
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Affiliation(s)
- M Cino
- Department of Clinical Neurological Sciences, Victoria Hospital, University of Western Ontario, London, Canada
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Sumegi B, Freeman DA, Inman L, Srere PA. Studies on a possible molecular basis for the structure of mitochondrial cristae. J Mol Recognit 1988; 1:19-24. [PMID: 2856223 DOI: 10.1002/jmr.300010105] [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
We have investigated a possible molecular basis for mitochondrial cristae formation. Proteoliposomes containing electron transport proteins, cytochrome oxidase, or complex III in their proper orientation bind to pig heart mitoplasts but not pig heart mitochondria. Using Leydig tumor cells, we have confirmed earlier reports that chloramphenicol causes a diminution in cristae content and a change in its characteristic lamellar form. We show that the proteoliposomes containing cytochrome oxidase or complex III in the proper orientation bind to mitoplasts from Leydig tumor cells but do not bind as well to mitoplasts from chloramphenicol-treated Leydig tumor cells. These experiments provide a possible mechanism to explain cristae formation.
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Affiliation(s)
- B Sumegi
- Pre-clinical Science Unit, VA Medical Center, Dallas, TX 75216
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Abstract
When nagarse is used to isolate brain mitochondria, a proportion of the nagarse stays associated with the mitochondrial fraction. This results in no detrimental affect on the respiratory activities. The nagarse is active in the presence of 2.3% sodium dodecyl sulfate and when samples are prepared for sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, the nagarse degrades a substantial amount of the mitochondrial proteins.
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Affiliation(s)
- E J Wilson
- Department of Clinical Neurological Sciences, University of Western Ontario, Victoria Hospital, London, Canada
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Biogenesis of Mammalian Mitochondria. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/b978-0-12-152515-6.50012-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Bunn CL, Baron JI, Mitchell D. Inherent resistance of HeLa cell derivatives to paromomycin. IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY : JOURNAL OF THE TISSUE CULTURE ASSOCIATION 1986; 22:381-6. [PMID: 3015861 DOI: 10.1007/bf02623526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The human tumor-derived cell line HeLa S3 and nuclear and mitochondrial gene mutants derived from it are resistant to the aminoglycoside antibiotic, paromomycin (PAR). Other carcinoma-derived cells, SV40-transformed cells, and four human diploid fibroblast cell lines are all sensitive to PAR. Sensitivity is dependent on cell density, and at cell numbers greater than 400/cm2 sensitive cells will proliferate in PAR. The resistance to PAR is inherited in a dominant manner in cell-to-cell fusion hybrids, but is not transferred in cytoplast-to-cell fusions. PAR resistance is therefore encoded by a nuclear gene(s). Resistance to PAR is not caused by changes in the response of mitochondrial or cytoplasmic protein synthesis to PAR in vitro. The uptake of PAR is similar in resistant and sensitive cells, and dimethyl sulfoxide does not render resistant cells more sensitive. Thus, HeLa cell PAR resistance is unlike previously reported ribosomal mutations and may derive from differences in the intracellular metabolism of PAR.
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Regulation of malic enzyme and mitochondrial alpha-glycerophosphate dehydrogenase by thyroid hormones, insulin, and glucocorticoids in cultured hepatocytes. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)68455-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Ziegler ML, Davidson RL. The effect of hexose on chloramphenicol sensitivity and resistance in Chinese hamster cells. J Cell Physiol 1979; 98:627-35. [PMID: 438306 DOI: 10.1002/jcp.1040980321] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Lipton JH, McMurray WC. Mitochondrial biogenesis in cultured mammalian cells. II. Mitochondrial protein and phospholipid synthesis in chloramphenicol-treated BHK-21 cells. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 477:273-87. [PMID: 884116 DOI: 10.1016/0005-2787(77)90052-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The effect of growth of BHK-21 cells in chloramphenicol on the synthesis of cellular proteins and phospholipids has been examined. The incorporation of leucine into total cellular proteins, or into the proteins of specific subcellular fractions are not significantly reduced by cell culture in the presence of chloramphenicol. In cells treated with cycloheximide, a small amount of chloramphenicol-sensitive labelling of protein was detected within the first hour of exposure to the drug. Chloramphenicol inhibits the incorporation of delta-amino-levulinic acid into hemoproteins, only if it is present during both the 48-h culturing and 4-h labelling period. De novo synthesis of cellular lipids as measured by pulse labelling with 32Pi or [3H]glycerol, is decreased in chloramphenicol-treated cells. This decrease is observed in all sub-cellular fractions, although the mitochondrial fraction is most affected. All phospholipids are affected, with diphosphatidylglycerol labelling reduced to the greatest extent. Although fatty acid synthesis is inhibited, the labelling of diphosphatidylglycerol with fatty acids is stimulated on chloramphenicol treatment.
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