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Martins VR, Brentani MM. The effects of ras gene expression on glucocorticoid receptors in mouse fibroblasts. J Steroid Biochem Mol Biol 1990; 37:183-93. [PMID: 1980081 DOI: 10.1016/0960-0760(90)90326-g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Analysis of induction of glutamine synthetase activity by dexamethasone showed a 2-fold increase in NIH3T3 but no change in NIH3T3 ras (EJ-ras) cells. The observed increase could be abolished by the antagonist RU486. The lack of response in ras transformed cells might reflect oncoprotein effects on the glucocorticoid receptor (GR). Several GR parameters were studied in order to clarify this point. Total GR level was the same for both cells; cytoplasmic receptor level however, was 3 times lower in NIH3T3 ras than in NIH3T3 cells. Hormone-receptor binding affinity, specificity, thermostability, sedimentation coefficient, molecular weight as well as the cytoplasmic GR transformation ratio were similar for the two cell lines. On the other hand, the fraction of the total receptor pool involved with the recycling process was approximately 20% lower in NIH3T3 ras than in NIH3T3 cells. After 24 h of dexamethasone treatment, no GR down regulation was observed in NIH3T3 ras cells, whereas normal NIH3T3 cells exhibited a decrease of GR binding capacity around 80%. Further studies are necessary to define the mechanisms underlying the association between glucocorticoid insensitivity, and modifications in the GR nuclear/cytoplasmic ratio, in the recycling GR fraction and in the down-regulation process observed in ras transformed cells.
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Affiliation(s)
- V R Martins
- Departamento de Clinica Medica, Faculdade de Medicina, Universidade de São Paulo, Brasil
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Juurlink BH. Effects of medium glutamine, glutamate, and ammonia on glutamine synthetase activity in cultured mouse astroglial cells. Neurochem Res 1987; 12:1053-8. [PMID: 2894616 DOI: 10.1007/bf00971704] [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
Mouse astroglial cells were grown during the last week of culture in either glutamine-free or glutamine-containing medium. The addition of cortisol to the glutamine-containing medium resulted in a doubling of astroglial glutamine synthetase (GS) activity. Withdrawal of glutamine from the medium resulted in a 50% elevation of GS and addition of cortisol to such a medium resulted in a further increase in GS which was not additive to glutamine withdrawal. Both in glutamine-free and glutamine-containing medium, the addition of glutamate resulted in a depression of both basal and cortisol induced GS activity. The simultaneous addition of ammonia plus glutamate to the culture medium ameliorated the glutamate mediated depressive effects on cortisol induced but not basal GS activity. Glutamine withdrawal from the culture medium resulted in an astroglial protein deficit. The addition of ammonia to the medium considerably reduced this deficit and the addition of glutamate completely eliminated this protein deficit.
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Affiliation(s)
- B H Juurlink
- Department of Anatomy, University of Saskatchewan, Saskatoon, Canada
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Patel AJ, Hunt A, Faraji-Shadan F. Effect of removal of glutamine and addition of dexamethasone on the activities of glutamine synthetase, ornithine decarboxylase and lactate dehydrogenase in primary cultures of forebrain and cerebellar astrocytes. Brain Res 1986; 391:229-38. [PMID: 2870781 DOI: 10.1016/0165-3806(86)90287-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The regulation of glutamine synthetase (GS) and ornithine decarboxylase (ODC) was studied in primary cultures of two types of astrocytes derived from either newborn forebrain or 8-day-old cerebellum of the rat. In the 14-day-old cultures the specific activities of both these enzymes were about twice as great in forebrain astrocytes as in cerebellar astrocytes. Treatment with dexamethasone or removal of glutamine from the culture medium caused a marked increase in the specific activity of GS. The glutamine-mediated relative increase in GS activity was similar in both types of astrocytes. Removal of glutamine caused a transient reduction in ODC activity in the forebrain astrocytes, while in cerebellar astrocytes the activity remained markedly decreased throughout the period of glutamine deprivation. The severe reduction in ODC activity had relatively little effect on the cell numbers of protein content of the astrocyte cultures. The increase in GS activities, involving protein synthesis de novo, caused by removal of glutamine and by addition of dexamethasone, were additive and therefore probably mediated by different mechanisms. The induction of GS after glutamine removal was blocked by cycloheximide but not by alpha-amanitin, suggesting regulation at the post-transcriptional level. In contrast, the dexamethasone-mediated induction of GS appeared to be regulated at the transcriptional level, as it was markedly reduced by alpha-amanitin. None of these conditions had any effect on lactate dehydrogenase activity. Treatment with alpha-amanitin resulted in a complete suppression of the activity of ODC (a protein with a very short half life), in both the control and dexamethasone treated cultures. However, this enzyme activity was reduced only partially in astrocytes cultured in glutamine deficient medium, suggesting that under these experimental conditions the mRNA may be markedly stabilized in astroglial cells.
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Patel AJ, Hunt A, Tahourdin CS. Regulation of in vivo glutamine synthetase activity by glucocorticoids in the developing rat brain. Brain Res 1983; 312:83-91. [PMID: 6140073 DOI: 10.1016/0165-3806(83)90123-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Induction of glutamine synthetase in vivo by glucocorticoids was studied in different brain regions of the rat during development. Corticosterone treatment resulted in an age-dependent increase in glutamine synthetase activity. In 11-day-old rats, in comparison with controls, the increase was about 80% in the cerebellum, 50% in the olfactory bulbs and 20% in the forebrain. During development the effect diminished markedly and at day 20 a marked increase was detectable only in the cerebellum, suggesting that the elevation of glutamine synthetase was dependent on the maturational state of the region at the time of hormone treatment. The increase in enzyme activity was dose-dependent, and was also observed after treatment with dexamethasone but not with testosterone, estradiol or progesterone. Pre-treatment with the protein synthesis inhibitor anisomycin blocked the hormonal response. Also, immunochemical detection of glutamine synthetase in brain homogenates fractionated by SDS-polyacrylamide gel electrophoresis and transferred to diazobenzyloxymethyl paper showed that the increase in enzyme activity was due to induction of protein synthesis. This may be the first report showing a regulation by glucocorticoids of mammalian brain glutamine synthetase in vivo, and it is in good agreement with previous findings with chick retina in vivo and various avian and mammalian cells in vitro.
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Keller BT, Landes GM, Kitos PA. Evidence for more than one mechanism of action of the glucocorticoid hormones. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 717:228-35. [PMID: 6126221 DOI: 10.1016/0304-4165(82)90174-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The data presented here provide evidence for at least two major cellular responses to the glucocorticoid hormones that do not seem to involve an interaction between the activated hormone-receptor complex and chromatin. We observed that 5mM pyridoxine in L-cell culture medium both increases the intracellular content of free pyridoxal phosphate by about 30% and decreases the glucocorticoid induction of glutamine synthetase to less than 30% of that at the normal (5 microM) concentration of the vitamin. Two other responses to the hormone-a major decrease in the polysome content of the cells and a decrease in the state of phosphorylation of ribosomal protein S6-are unaffected by the 5mM dose of the vitamin. In light of the findings of DiSorbo and Litwack ((1981) Biochem. Biophys. Res. Commun. 99, 1203-1208), pyridoxal phosphate appears to modulate the enzyme-inducing activity of dexamethasone in L-cells but not the polysome and ribosome related changes. These results are consistent with the hypothesis that certain important glucocorticoid induced responses are independent of nuclear function.
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Lacoste L, Chaudhary KD, Lapointe J. Derepression of the glutamine synthetase in neuroblastoma cells at low concentrations of glutamine. J Neurochem 1982; 39:78-85. [PMID: 6123553 DOI: 10.1111/j.1471-4159.1982.tb04703.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Regulation of the biosynthesis of glutamine synthetase was studied in neuroblastoma cells (Neuro-2A) by use of a recently developed, sensitive radioisotopic assay. The removal of glutamine from the culture medium of these cells for 24 h resulted in a 10-fold increase in glutamine synthetase specific activity (15-fold after 2 weeks) compared with the basal level found in cells grown in the presence of 2 mM glutamine. Following the growth of these cells for 2 weeks in the presence of various concentrations of glutamine, a negative linear correlation was observed between the specific activity of glutamine synthetase (from 1.7 to 0.14 unit/mg) and the concentration of glutamine in the growth medium (from 0.5 to 2 mM). Cycloheximide or actinomycin D blocked the increase in glutamine synthetase activity observed in the absence of glutamine. These results suggest that the removal of glutamine led to the induction of glutamine synthetase by stimulating new enzyme synthesis. The enzyme was not degraded, but only diluted, by growth upon readdition of glutamine to the medium. The influence of glutamine depletion is also reported for C-6 glioma cells and glial cells in primary cultures.
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Harmon JM, Thompson EB. Glutamine synthetase induction by glucocorticoids in the glucocorticoid-sensitive human leukemic cell line CEM-C7. J Cell Physiol 1982; 110:155-60. [PMID: 6121820 DOI: 10.1002/jcp.1041100208] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Treatment of CEM-C7 cells with glucocorticoids produces a 2.5-fold increase in the activity of the enzyme glutamine synthetase (GS). This increase is specific for steroids with glucocorticoid activity adn occurs over a range of steroid concentrations consistent with a receptor-mediated mechanism. Half-maximal and maximal inductions by dexamethasone (dex) occur at 2 X 10(-8) M and 2 X 10(-7) M dex, respectively, concentrations approximately equal to those necessary to produce half and full occupancy of glucocorticoid receptors. GS activity began to increase 1 hour after dex treatment and was complete by 12 hours. This is well before any of the growth inhibitory or cytolytic effects of dex on this cell line occur. This increase was dependent on the presence of glucocorticoid receptors and required both RNA and protein synthesis. Removal of dex following stimulation to maximal levels resulted in a decrease of GS activity to preinduced levels with a half-time of 5 hours. Glutamine deprivation of cells resulted in increased GS activity. However, even in the total absence of glutamine, dex treatment elicited a 2.0-2.5-fold increase in GS activity, ruling out inhibition of glutamine uptake as a mechanism for the dex-induced increase. Experiments with 5'-bromodeoxyuridine (BrdU) demonstrated that GS elevation was sensitive to BrdU substitution of DNA, while dex-induced growth inhibition was not. Therefore GS elevation and growth inhibition in this cell line appear to be independently expressed steroid responses.
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Hackney JF, Holbrook NJ, Grasso RJ. Progesterone as a partial glucocorticoid agonist in L929 mouse fibroblasts: effects on cell growth, glutamine synthetase induction and glucocorticoid receptors. JOURNAL OF STEROID BIOCHEMISTRY 1981; 14:971-7. [PMID: 6117674 DOI: 10.1016/0022-4731(81)90204-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Pishak MR, Phillips AT. Glucocorticoid stimulation of glutamine synthetase production in cultured rat glioma cells. J Neurochem 1980; 34:866-72. [PMID: 6102113 DOI: 10.1111/j.1471-4159.1980.tb09659.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Grodin M, Nystrom R, Scordato J, Cantor MH, Oppenheimer SB. Relationship of adhesiveness of cells in culture with specific enzyme activity. Exp Cell Res 1979; 122:149-57. [PMID: 38979 DOI: 10.1016/0014-4827(79)90569-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Arad G, Kulka RG. Effects of glutamine, methionine sulfone and dexamethasone on rates of synthesis of glutamine synthetase in cultured hepatoma cells. Biochim Biophys Acta Gen Subj 1978; 544:153-62. [PMID: 31191 DOI: 10.1016/0304-4165(78)90219-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glutamine synthetase (EC 6.3.1.2) activity of hepatoma tissue culture cells is elevated by corticosteroids and depressed by glutamine (Kulka, R.G., Tomkins, G.M. and Crook, R.B. (1972) J. Cell Biol., 54, 175--179). The transfer of cells from high (1--5 mM) to low (0.2--0.4 mM) concentrations of glutamine causes a marked increase in glutamine synthetase activity. The addition of a glutamine antagonist, methionine sulfone (1 mM) to cells suspended in high (1 mM) concentrations of glutamine also causes an increase of glutamine synthetase activity which is greater than that elicited by the transfer of cells to low concentrations of glutamine. Rates of synthesis of glutamine synthetase have been measured by radioimmunoprecipitation in hepatoma tissue culture cells incubated under various conditions. Incubation of cells with the synthetic corticosteroid hormone, dexamethasone, markedly stimulates the relative rate of glutamine synthetase biosynthesis. Glutamine, or its analogue, methionine sulfone, have no effect on the relative rate of synthesis of the enzyme. However, total protein and RNA synthesis increase markedly with increasing external glutamine concentration in the range 0--1 mM. Methionine sulfone (1 mM) inhibits the degradation of glutamine synthetase in the presence of 1 mM glutamine. The data are consistent with the conclusion that the corticosteroid, dexamethasone, elevates glutamine synthetase activity by stimulating its rate of synthesis, whereas methionine sulfone elevates glutamine synthetase activity by inhibiting the glutamine-stimulated degradation of preformed enzyme.
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Crook R, Louie M, Deuel T, Tomkins G. Regulation of glutamine synthetase by dexamethasone in hepatoma tissue culture cells. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34589-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Viceps-Madore D, Cristofalo VJ. Age-associated changes in glutamine synthetase activity in WI-38 cells. Mech Ageing Dev 1978; 8:43-50. [PMID: 29170 DOI: 10.1016/0047-6374(78)90005-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The human fibroblast cell line WI-38 shows a gradual decline in glutamine synthetase specific activity with increasing age in culture. However, the level of functional enzyme per cell does not change with age. Heat inactivation profiles indicate that glutamine synthetase from younger cell cultures is more heat labile than that from older cultures. A possible explanation for these observations is that alterations in the glutamine synthetase molecule occur with increasing age of WI-38 cells in culture.
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Drummond RJ, Phillips AT. Intracellular amino acid content of neuronal, glial, and non-neural cell cultures: the relationship to glutamic acid compartmentation. J Neurochem 1977; 29:101-8. [PMID: 886314 DOI: 10.1111/j.1471-4159.1977.tb03930.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
In the presence of complete growth media (Eagle's MEM), human diploid WI-38 cells have a low level of glutamine synthetase activity. The activity could be increased by depriving the cells of exogenous glutamine; addition of hydrocortisone to either glutamine-deficient or complete medium had no effect on the acitivty of the enzyme. Cell growth ceased under conditions that enhanced glutamine synthetase activity, and hydrocortisone could not reverse this inhibition.
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17
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Reif-Lehrer L, Lindewall D. Control of gamma-glutamyltransferase activity in chick embryo retinas by glutamine. Exp Eye Res 1975; 20:135-42. [PMID: 235442 DOI: 10.1016/0014-4835(75)90151-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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18
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Milman G, Portnoff LS, Tiemeier DC. Immunochemical evidence for glutamine-mediated degradation of glutamine synthetase in cultured Chinese hamster cells. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)41826-7] [Citation(s) in RCA: 28] [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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Barnes PR, Hersh RT, Kitos PA. Regulation of glutamine synthetase in L cells by cortisol and L-glutamine. IN VITRO 1974; 9:230-8. [PMID: 4157200 DOI: 10.1007/bf02616068] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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20
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Regulation of Glutamine Synthetase Activity of Hepatoma Tissue Culture Cells by Glutamine and Dexamethasone. J Biol Chem 1973. [DOI: 10.1016/s0021-9258(19)43415-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Higuchi K, Robinson RC. Studies on the cultivation of mammalian cell lines in a serum-free, chemically defined medium. IN VITRO 1973; 9:114-121. [PMID: 4202509 DOI: 10.1007/bf02616009] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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22
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Stamatiadou MN. Inhibition by serotonin of glutamine synthetase formation in cultured mouse cells strain L. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 304:169-80. [PMID: 4144718 DOI: 10.1016/0304-4165(73)90125-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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23
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Raivio KO, Seegmiller JE. Role of glutamine in purine synthesis and in guanine nucleotide formation in normal fibroblasts and in fibroblasts deficient in hypoxanthine phosphoribosyltransferase activity. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 299:283-92. [PMID: 4706454 DOI: 10.1016/0005-2787(73)90351-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Higuchi K. Cultivation of animal cells in chemically defined media, a review. ADVANCES IN APPLIED MICROBIOLOGY 1973; 16:111-36. [PMID: 4206269 DOI: 10.1016/s0065-2164(08)70025-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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25
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Tiemeier DC, Milman G. Regulation of Glutamine Synthetase in Cultured Chinese Hamster Cells. J Biol Chem 1972. [DOI: 10.1016/s0021-9258(19)44819-9] [Citation(s) in RCA: 34] [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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26
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Kulka RG, Tokins GM, Crook RB. Clonal differences in glutamine synthetase activity of hepatoma cells. Effects of glutamine and dexamethasone. J Cell Biol 1972; 54:175-9. [PMID: 4402645 PMCID: PMC2108855 DOI: 10.1083/jcb.54.1.175] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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27
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Richards K, Kitos PA, Hersh RT. Action of ribonuclease upon the polysomes of cultured mouse cells. IN VITRO 1972; 8:48-57. [PMID: 4672902 DOI: 10.1007/bf02617943] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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28
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Stamatiadou MN. Effects of glutamine on the two catalytic activities of glutamine synthetase in cultured mouse cells strain L. Biochem Biophys Res Commun 1972; 47:485-90. [PMID: 4145504 DOI: 10.1016/0006-291x(72)90740-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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