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Rabinovitz M. Uncharged tRNA-phosphofructokinase interaction in amino acid deficiency. Amino Acids 1996; 10:99-108. [DOI: 10.1007/bf00806583] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/1995] [Accepted: 09/29/1995] [Indexed: 11/29/2022]
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2
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Mabrouk T, Danis C, Lemay G. Two basic motifs of reovirus sigma 3 protein are involved in double-stranded RNA binding. Biochem Cell Biol 1995; 73:137-45. [PMID: 7576487 DOI: 10.1139/o95-017] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
It has been reported that the sigma 3 protein of reovirus can exert an inhibitory effect on the cellular double-stranded RNA (dsRNA) activated protein kinase. Activation of this kinase is thought to be a general mechanism mediating a cellular antiviral response. This enzyme can also be activated upon transfection, resulting in translational inhibition of plasmid-encoded mRNAs. sigma 3 has an affinity for dsRNA postulated to be responsible for antikinase activity. In the present study, site-directed mutagenesis was performed on two basic regions previously suggested as dsRNA-binding motifs and the mutant sigma 3 proteins were then expressed in COS cells. These experiments revealed that both motifs are involved in sigma 3 attachment to RNA. Expression of the mutants lacking RNA-binding capability is stimulated by coexpression of another dsRNA-binding protein, the E3L vaccinia virus protein. These results support a model in which the attachment to dsRNA is directly responsible for the trans-stimulating effect of sigma 3 on expression of cotransfected genes.
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Affiliation(s)
- T Mabrouk
- Département de microbiologie et immunologie, Université de Montréal, Canada
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3
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Lee TG, Katze MG. Cellular inhibitors of the interferon-induced, dsRNA-activated protein kinase. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 1994; 14:48-65. [PMID: 7914806 DOI: 10.1007/978-3-642-78549-8_4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- T G Lee
- Department of Microbiology, School of Medicine, University of Washington, Seattle 98195
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4
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Sharp TV, Schwemmle M, Jeffrey I, Laing K, Mellor H, Proud CG, Hilse K, Clemens MJ. Comparative analysis of the regulation of the interferon-inducible protein kinase PKR by Epstein-Barr virus RNAs EBER-1 and EBER-2 and adenovirus VAI RNA. Nucleic Acids Res 1993; 21:4483-90. [PMID: 7901835 PMCID: PMC311179 DOI: 10.1093/nar/21.19.4483] [Citation(s) in RCA: 149] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The interferon-inducible protein kinase PKR interacts with a number of small viral RNA species, including adenovirus VAI RNA and the Epstein-Barr virus-encoded RNA EBER-1. These RNAs bind to PKR and protect protein synthesis from inhibition by double-stranded RNA in the reticulocyte lysate system. Using a peptide phosphorylation assay we show here that EBER-1, like VAI, directly inhibits the activation of purified PKR. A second Epstein-Barr virus RNA, EBER-2, also regulates PKR. EBER-1, EBER-2 and VAI RNA exhibit mutually competitive binding to the native or recombinant enzyme, as assessed by U.V. crosslinking experiments and filter binding assays. The affinities of all three RNAs for PKR in vitro are similar (Kd = ca. 0.3 nM). Since this protein kinase has been proposed to exert a tumour suppressor function in vivo, the ability of EBER-1 to inhibit its activation suggests a role for this small RNA in cell transformation by Epstein-Barr virus.
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Affiliation(s)
- T V Sharp
- Department of Cellular and Molecular Sciences, St George's Hospital Medical School, London, UK
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5
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Inducible transcriptional activation of the human immunodeficiency virus long terminal repeat by protein kinase inhibitors. Mol Cell Biol 1993. [PMID: 8355680 DOI: 10.1128/mcb.13.9.5245] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The protein kinase inhibitor 2-aminopurine (2-AP) greatly stimulated expression in human promonocytes-macrophages of plasmid constructs carrying various reporter genes (chloramphenicol acetyltransferase, lacZ, firefly luciferase [luc], and Salmonella typhimurium histidinol dehydrogenase [his]) driven by the human immunodeficiency virus type 1 (HIV-1) long terminal repeat. Adenine, adenosine, and caffeine were also effective inducers, but other purine or pyrimidine derivatives were ineffective. Experiments with mutant derivatives of the HIV-1 long terminal repeat revealed no specific eukaryotic promoter elements necessary for 2-AP induction but indicated the need for some minimum combination of such elements. Induction of HIV-1-directed gene expression appeared not to require action of the transcription factor NF-kappa B. The mechanism of induction was investigated by using the luc and his genes linked to the HIV-1 long terminal repeat. 2-AP induced marked, steady rises in mRNA accumulation from both transfected and chromosomally integrated HIV-1 constructs but no increases from an endogenous gene encoding gamma-actin or glucose 6-phosphate dehydrogenase. Thus, induction is selective and not an artifact induced by transfecting DNA into cells. In run-on transcription experiments, the rates of transcription initiation of both transfected and integrated copies of the his gene increased about sixfold in cells treated with 2-AP. Thus, while increased initiation accounted for a portion of 2-AP induction, it could not cause the far greater increase in steady-state mRNA levels. 2-AP induction did not change mRNA decay rates and differed from the phorbol ester (phorbol myristate acetate)-induced activation of the protein kinase C-NF-kappa B pathway in its time course and in its requirement for new protein synthesis. Gel retardation assays showed that unlike phorbol myristate acetate induction, 2-AP induction is enhancer independent. Whereas many previous studies have implicated the activation of various protein kinases in gene induction, we here describe a mechanism of gene activation that appears to involve protein kinase inhibition as a component of the induction response.
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6
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Brown FL, Tahaoglu E, Graham GJ, Maio JJ. Inducible transcriptional activation of the human immunodeficiency virus long terminal repeat by protein kinase inhibitors. Mol Cell Biol 1993; 13:5245-54. [PMID: 8355680 PMCID: PMC360213 DOI: 10.1128/mcb.13.9.5245-5254.1993] [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: 01/30/2023] Open
Abstract
The protein kinase inhibitor 2-aminopurine (2-AP) greatly stimulated expression in human promonocytes-macrophages of plasmid constructs carrying various reporter genes (chloramphenicol acetyltransferase, lacZ, firefly luciferase [luc], and Salmonella typhimurium histidinol dehydrogenase [his]) driven by the human immunodeficiency virus type 1 (HIV-1) long terminal repeat. Adenine, adenosine, and caffeine were also effective inducers, but other purine or pyrimidine derivatives were ineffective. Experiments with mutant derivatives of the HIV-1 long terminal repeat revealed no specific eukaryotic promoter elements necessary for 2-AP induction but indicated the need for some minimum combination of such elements. Induction of HIV-1-directed gene expression appeared not to require action of the transcription factor NF-kappa B. The mechanism of induction was investigated by using the luc and his genes linked to the HIV-1 long terminal repeat. 2-AP induced marked, steady rises in mRNA accumulation from both transfected and chromosomally integrated HIV-1 constructs but no increases from an endogenous gene encoding gamma-actin or glucose 6-phosphate dehydrogenase. Thus, induction is selective and not an artifact induced by transfecting DNA into cells. In run-on transcription experiments, the rates of transcription initiation of both transfected and integrated copies of the his gene increased about sixfold in cells treated with 2-AP. Thus, while increased initiation accounted for a portion of 2-AP induction, it could not cause the far greater increase in steady-state mRNA levels. 2-AP induction did not change mRNA decay rates and differed from the phorbol ester (phorbol myristate acetate)-induced activation of the protein kinase C-NF-kappa B pathway in its time course and in its requirement for new protein synthesis. Gel retardation assays showed that unlike phorbol myristate acetate induction, 2-AP induction is enhancer independent. Whereas many previous studies have implicated the activation of various protein kinases in gene induction, we here describe a mechanism of gene activation that appears to involve protein kinase inhibition as a component of the induction response.
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Affiliation(s)
- F L Brown
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461
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7
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Mundschau L, Faller D. Oncogenic ras induces an inhibitor of double-stranded RNA-dependent eukaryotic initiation factor 2 alpha-kinase activation. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)50061-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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8
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Feng GS, Chong K, Kumar A, Williams BR. Identification of double-stranded RNA-binding domains in the interferon-induced double-stranded RNA-activated p68 kinase. Proc Natl Acad Sci U S A 1992; 89:5447-51. [PMID: 1351683 PMCID: PMC49309 DOI: 10.1073/pnas.89.12.5447] [Citation(s) in RCA: 142] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The double-stranded RNA (dsRNA)-binding domain of the human p68 kinase has been localized to the N-terminal half of the enzyme by using progressive deletion analysis and in vitro binding assays. To further define the domains responsible for binding to dsRNA, we cloned the mouse dsRNA-activated p65 kinase and used sequence alignment to identify conserved domains in the N-terminal region. Deletions in either of two 12-amino-acid-long and arginine- or lysine-rich regions abrogated binding to dsRNA. Moreover, in an in vivo growth inhibition assay in the yeast Saccharomyces cerevisiae, these mutants failed to exhibit a slow-growth phenotype.
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Affiliation(s)
- G S Feng
- Research Institute, Hospital for Sick Children, Toronto, Canada
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9
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Rabinovitz M. The pleiotypic response to amino acid deprivation is the result of interactions between components of the glycolysis and protein synthesis pathways. FEBS Lett 1992; 302:113-6. [PMID: 1321723 DOI: 10.1016/0014-5793(92)80418-g] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Several diverse metabolic events become compromised when mammalian cells are made deficient in essential amino acids or when charging of their tRNA is blocked by amino acid analogs. This rapid general demise of cell function can be due to inhibition of phosphofructokinase (PFK) by uncharged tRNA. It has now been demonstrated that when tRNA is added to PFK in an assay dependent upon the reassociation of inactive, dissociated enzyme subunits, nanomolar concentrations cause complete inhibition. The model for control suggests that charged tRNA becomes associated with EF-1, which is specific for aminoacyl-tRNAs and is present in sufficiently high concentrations in cells to sequester that charged forms from an inhibitory role. Support for this model include: (1) the rapid onset of inhibition of glycolysis and glucose uptake upon amino acid deficiency; (2) the unique role of the product of PFK activity, fructose-1,6-diphosphate, in reactions of peptide chain initiation, particularly its role as a co-factor for purified eIF-2B, the GDP/GTP exchange factor; (3) the correlations of this interaction with the cellular and molecular lesions of insulin insufficiency; (4) the recognition that the anomalous role of high concentrations of cAMP as a stimulant of peptide chain initiation in energy depleted or gel-filtered cell lysates correlates with its stimulatory action on PFK as an analog for the positive effector, adenosine-5'-monophosphate; and (5) the role of fructose-1,6-diphosphate in the formation of glyceraldehyde-3-phosphate, a substrate for synthesis of ribose-5-phosphate via the non-oxidative portion of the pentose phosphate pathway, which, as a precursor of phosphoribosylpyrophosphate, is essential for nucleic acid synthesis.
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Affiliation(s)
- M Rabinovitz
- Laboratory of Molecular Pharmacology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
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10
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Dioxin-dependent activation of murine Cyp1a-1 gene transcription requires protein kinase C-dependent phosphorylation. Mol Cell Biol 1992. [PMID: 1312672 DOI: 10.1128/mcb.12.4.1856] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcriptional activation of the murine Cyp1a-1 (cytochrome P(1)450) gene by inducers such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (dioxin) requires the aromatic hydrocarbon (Ah) receptor and the interaction of an inducer-receptor complex with one or more of the Ah-responsive elements (AhREs) located about 1 kb upstream from the transcriptional initiation site. We find that treatment of mouse hepatoma Hepa-1 cells with 2-aminopurine, an inhibitor of protein kinase activity, inhibits CYP1A1 mRNA induction by TCDD as well as the concomitant increase in CYP1A1 enzyme activity. Formation of DNA-protein complexes between the Ah receptor and its AhRE target is also inhibited by 2-aminopurine, as determined by gel mobility shift assays. Phosphorylation is required for the formation of Ah receptor-specific complexes, since in vitro dephosphorylation of nuclear extracts from TCDD-treated Hepa-1 cells abolishes the capacity of the Ah receptor to form specific complexes with its cognate AhRE sequences. To determine whether any one of several known protein kinases was involved in the transcriptional regulation of the Cyp1a-1 gene, we treated Hepa-1 cells with nine other protein kinase inhibitors prior to induction with TCDD; nuclear extracts from these cells were analyzed for their capacity to form specific DNA-protein complexes. Only extracts from cells treated with staurosporine, a protein kinase C inhibitor, were unable to form these complexes. In addition, staurosporine completely inhibited CYP1A1 mRNA induction by TCDD. Depletion of protein kinase C by prolonged treatment with phorbol ester led to the complete suppression of CYP1A1 mRNA induction by TCDD. We conclude that (i) phosphorylation is necessary for the formation of a transcriptional complex and for transcriptional activation of the Cyp1a-1 gene; (ii) the phosphorylation site(s) exists on at least one of the proteins constituting the transcriptional complex, possibly the Ah receptor itself; and (iii) the enzyme responsible for the phosphorylation is likely to be protein kinase C.
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11
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Carrier F, Owens RA, Nebert DW, Puga A. Dioxin-dependent activation of murine Cyp1a-1 gene transcription requires protein kinase C-dependent phosphorylation. Mol Cell Biol 1992; 12:1856-63. [PMID: 1312672 PMCID: PMC369629 DOI: 10.1128/mcb.12.4.1856-1863.1992] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Transcriptional activation of the murine Cyp1a-1 (cytochrome P(1)450) gene by inducers such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (dioxin) requires the aromatic hydrocarbon (Ah) receptor and the interaction of an inducer-receptor complex with one or more of the Ah-responsive elements (AhREs) located about 1 kb upstream from the transcriptional initiation site. We find that treatment of mouse hepatoma Hepa-1 cells with 2-aminopurine, an inhibitor of protein kinase activity, inhibits CYP1A1 mRNA induction by TCDD as well as the concomitant increase in CYP1A1 enzyme activity. Formation of DNA-protein complexes between the Ah receptor and its AhRE target is also inhibited by 2-aminopurine, as determined by gel mobility shift assays. Phosphorylation is required for the formation of Ah receptor-specific complexes, since in vitro dephosphorylation of nuclear extracts from TCDD-treated Hepa-1 cells abolishes the capacity of the Ah receptor to form specific complexes with its cognate AhRE sequences. To determine whether any one of several known protein kinases was involved in the transcriptional regulation of the Cyp1a-1 gene, we treated Hepa-1 cells with nine other protein kinase inhibitors prior to induction with TCDD; nuclear extracts from these cells were analyzed for their capacity to form specific DNA-protein complexes. Only extracts from cells treated with staurosporine, a protein kinase C inhibitor, were unable to form these complexes. In addition, staurosporine completely inhibited CYP1A1 mRNA induction by TCDD. Depletion of protein kinase C by prolonged treatment with phorbol ester led to the complete suppression of CYP1A1 mRNA induction by TCDD. We conclude that (i) phosphorylation is necessary for the formation of a transcriptional complex and for transcriptional activation of the Cyp1a-1 gene; (ii) the phosphorylation site(s) exists on at least one of the proteins constituting the transcriptional complex, possibly the Ah receptor itself; and (iii) the enzyme responsible for the phosphorylation is likely to be protein kinase C.
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Affiliation(s)
- F Carrier
- Laboratory of Developmental Pharmacology, National Institute of Child Health and Human Development, Bethesda, Maryland 20892
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12
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DeBernardi MA, Brooker G. 2-Aminopurine inhibits RNA and protein synthesis and reduces catecholamine desensitization in C6-2B rat glioma cells. FEBS Lett 1992; 296:112-6. [PMID: 1370421 DOI: 10.1016/0014-5793(92)80415-d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We previously proposed that intracellular cyclic AMP accumulation induces a putative, rapidly turning over protein inhibitory to further hormone activation of adenylate cyclase. In the present study, 2-aminopurine, which has been reported to selectively block c-fos gene expression, was used to test the hypothesis that c-fos protein might be involved in the desensitization to catecholamines was observed in 2-aminopurine-treated C6-2B rat glioma cells. However, we found 2-aminopurine to inhibit, in a concentration-dependent manner, total cellular RNA and protein synthesis in C6-2B, HeLa, Swiss 3T3 and BALB/c cells. mRNA synthesis was also markedly reduced in 2-aminopurine-treated cells. These unexpected findings, while supporting our hypothesis of a protein synthesis-sensitive step in the development of refractoriness, raise concern about the specificity of action of 2-aminopurine to inhibit c-fos induction and thus any cellular process, including desensitization, which might be regulated by c-fos gene expression.
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Affiliation(s)
- M A DeBernardi
- Department of Biochemistry and Molecular Biology, Georgetown University School of Medicine, Washington, DC 20007
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13
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Abstract
Interferons (IFN) stimulate the expression of a number of genes following interaction with specific high-affinity plasma membrane receptors. The products of these genes either singly or coordinately mediate the antiviral, growth inhibitory or immunoregulatory activities attributed to IFN. While the gene products in some cases have been well characterized, other IFN-regulated genes encode proteins whose functions have yet to be elucidated. A feature common to all IFN-stimulated genes characterized thus far is the presence of a DNA element which constitutes an IFN-responsive enhancer, usually present in the 5' upstream region of the genes. This element, termed interferon-stimulated response element (ISRE) binds a nuclear factor(s) translocated from the cytoplasm to the nucleus following IFN-receptor-triggered signal transduction. The binding of these factors to the ISRE represents the initiating event in stimulating RNA-polymerase-II-mediated transcription from IFN-responsive genes. Depending on the nature of the cells responding to IFN and the genes involved, induced transcription may be prolonged or rapidly terminated. The rapid termination of transcription is dependent in some cases on IFN-induced protein synthesis and also involves factor binding to the ISRE. Recent progress in detailing these events will be discussed including IFN-receptor interactions, signal-transduction pathways, comparing and contrasting IFN-regulated genes and elucidation of IFN-regulated factors.
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Affiliation(s)
- B R Williams
- Research Institute, Hospital for Sick Children, Canada
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Steinmann KE, Belinsky GS, Lee D, Schlegel R. Chemically induced premature mitosis: differential response in rodent and human cells and the relationship to cyclin B synthesis and p34cdc2/cyclin B complex formation. Proc Natl Acad Sci U S A 1991; 88:6843-7. [PMID: 1830667 PMCID: PMC52185 DOI: 10.1073/pnas.88.15.6843] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Normal eukaryotic cells do not initiate mitosis until DNA replication has been completed. This requirement can be bypassed by exposing cells to certain chemicals. We report here that chemically induced premature mitosis is not readily achieved in all mammalian species. Although hamster cells underwent premature mitosis following treatment with caffeine, the protein phosphatase inhibitor okadaic acid, and the protein kinase inhibitors 2-aminopurine and 6-dimethyl-aminopurine, the mouse and human cells examined in this study displayed little or no response to any of these compounds. Differences in cell permeability or metabolism could not account for the species specificity of these drugs, because other biochemical and mitosis-promoting activities were apparent in human cells. Cell-type specificity can be explained, however, by the timing of cyclin B synthesis and p34cdc2/cyclin B complex formation during the cell cycle. Synthesis of cyclin B and formation of a p34cdc2/cyclin B complex, both of which are required for initiation of mitosis, were prevalent in hamster cells arrested in S phase but were absent or barely detectable in arrested human cells. In hamster cells, the hyperphosphorylated form of p34cdc2 was complexed with cyclin B and underwent tyrosine dephosphorylation during caffeine-induced premature mitosis. These findings indicate that the onset of mitosis is regulated somewhat differently among mammalian cell types and that these differences affect the vulnerability of cells to drug-induced mitotic aberrations and cytogenetic damage.
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Affiliation(s)
- K E Steinmann
- Charles A. Dana Laboratory of Toxicology, Harvard School of Public Health, Boston, MA 02115
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15
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Williams BR. Signal transduction and transcriptional regulation of interferon-alpha-stimulated genes. JOURNAL OF INTERFERON RESEARCH 1991; 11:207-13. [PMID: 1680934 DOI: 10.1089/jir.1991.11.207] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Interferon-alpha (IFN-alpha) stimulates the expression of a number of genes in a pathway that begins with binding to specific high-affinity plasma membrane receptors. All IFN-alpha-stimulated genes cloned thus far are characterized by the presence of a DNA element, termed Interferon-Stimulated Response Element (ISRE), usually in the 5' upstream region of the genes. The ISRE binds a nuclear factor(s) following IFN-receptor triggered signal transduction and provides a convenient assay for the rapid phase of IFN-alpha signal transduction. This phase utilizes a phospholipase A2-generated second messenger which modulates ISRE-binding factors. Expression cloning has resulted in the identification of two specific ISRE-binding proteins that are candidates as signal recipients. Further advances in our understanding of the molecular mechanisms of IFN action may come through the use of yeast genetics. The human p68 kinase expressed in yeast has a growth inhibitory phenotype and provides a useful alternative system for analyzing components of the IFN-stimulated pathways.
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Affiliation(s)
- B R Williams
- Research Institute, Hospital for Sick Children, University of Toronto, Canada
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16
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Tamm I, Kikuchi T. Activation of signal transduction pathways protects quiescent Balb/c-3T3 fibroblasts against death due to serum deprivation. J Cell Physiol 1991; 148:85-95. [PMID: 1713593 DOI: 10.1002/jcp.1041480111] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Platelet-derived growth factor (PDGF), epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1), and insulin protect density-inhibited murine Balb/c-3T3 fibroblasts against death by distinctive mechanisms. Determination of the cell survival-enhancing activity of growth factors by cell enumeration and neutral red uptake measurement gives equivalent results. PDGF displays a steep dose-response relationship in the 1-5 ng/ml range. The other factors display shallow log-linear relationships in the following ranges: EGF: 0.2-5 ng/ml; IGF-1: 2-80 ng/ml; and insulin: 57-4,500 ng/ml. Agonists that lead to the activation of protein kinase A, including forskolin, 8-bromoadenosine 3':5'-cyclic monophosphate (Br-cAMP) and N6,2'-O-dibutyryladenosine 3':5'-cyclic monophosphate (db-cAMP), markedly increase both short-term (5-h) and long-term (20-h) survival of cells. 2-Isobutyl-1-methylxanthine (IBMX) markedly enhances short-term survival, but its effect decays with time. The protein kinase C agonist 12-O-tetradecanoyl phorbol-13-acetate (TPA) has a moderate protective effect at concentrations of 16-32 nM, and 64 nM TPA is highly effective. The synthetic diaclglycerols 1,2-dioctanoylglycerol (DiC8) and 1-oleoyl-2-acetylglycerol (OAG) and the calcium ionophore ionomycin show low activity. Supplementation of EGF with a protein kinase A or C agonist results in a varying additive increase in short-term (5-h) cell survival and supplementation of EGF + insulin or PDGF + EGF + insulin increases further the already high level of protection given by the growth factor combinations. Combining a protein kinase A and a protein kinase C agonist in the absence of growth factors gives an approximately additive increase in cell survival. Results obtained with kinase, RNA, and protein synthesis inhibitors suggest that: 1) activated protein kinase C catalyzes one or more phosphorylation events in quiescent Balb/c-3T3 cells that lead to gene expression with the protein product(s) mediating protection of quiescent cells against death, and 2) phosphorylation events catalyzed by protein kinase A largely serve to protect cells by a mechanism not requiring de novo RNA and protein biosynthesis.
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Affiliation(s)
- I Tamm
- Rockefeller University, New York, New York 10021
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17
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Enhancement of expression of exogenous genes by 2-aminopurine. Regulation at the post-transcriptional level. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(17)35254-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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18
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Boeggeman E, Masibay AS, Qasba PK, Sreevalsan T. Identification and partial characterization of genes that are transactivated by different pathways in quiescent mouse cells stimulated with serum. J Cell Physiol 1990; 145:286-94. [PMID: 1978837 DOI: 10.1002/jcp.1041450213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have identified four cDNA clones, cl-1, cl-5, cl-15, and cl-16, that represent genes induced by serum in resting mouse 3T3 cells. Partial sequence analysis of the four cDNAs indicated that cl-15 corresponds to the mouse beta-actin gene. Comparison of the DNA sequences of the other three clones with the sequence data bank (Genbank) showed little homology to other known DNA sequences and thus represent novel genes. The level of the mRNAs corresponding to the four genes began to increase in resting cells following serum stimulation, reached a peak between 5 h and 8 h and then started to decline. Inhibitors of transcription diminished the induction of the mRNAs corresponding to the four genes. Cycloheximide and anisomycin had little effect on the induction of beta actin mRNA while the induction of the other three genes was suppressed by the same inhibitors. 12-O-Tetradecanoylphorbol-13-acetate and the calcium ionophore A23187 enhanced the expression of the cl-16 mRNA while epidermal growth factor, fibroblast growth factor, or insulin enhanced the expression of cl-1- and cl-5-specific transcripts. The level of beta-actin mRNA was elevated in resting cells by epidermal growth factor and 12-O-tetradecanoylphorbol-13-acetate and to a lesser extent by fibroblast growth factor, insulin, and dibutyryl cyclic AMP-elevating agents. Pertussis toxin, an inhibitor of the action of G proteins, did not significantly suppress the activation of the four genes by serum. However, 2-aminopurine, a protein kinase inhibitor, suppressed the induction of the four transcripts in serum-stimulated cells. The possible pathways involved in the activation of these genes in resting cells are discussed.
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Affiliation(s)
- E Boeggeman
- Department of Microbiology, Georgetown University School of Medicine, Washington, D.C. 20007
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19
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DeStefano J, Olmsted E, Panniers R, Lucas-Lenard J. The alpha subunit of eucaryotic initiation factor 2 is phosphorylated in mengovirus-infected mouse L cells. J Virol 1990; 64:4445-53. [PMID: 2166823 PMCID: PMC247914 DOI: 10.1128/jvi.64.9.4445-4453.1990] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Infection of mouse L cells with mengovirus resulted in the activation of a protein kinase (PK) that selectively phosphorylated the small, 38,000-molecular-weight alpha subunit of eucaryotic initiation factor 2 (eIF-2) in vitro. The mengovirus-activated kinase was detected in vitro approximately 3 h after virus adsorption. The ratio of phosphorylated to unphosphorylated eIF-2 also increased in vivo between 3 and 7 h after adsorption. The virus-activated kinase fractionated with the ribosomal pellet and had a high affinity for DEAE-cellulose and Mono Q ion-exchange columns. Gel electrophoresis of the kinase activity eluting from the Mono Q column and silver staining of the gel revealed only one protein band with a molecular mass of 70 kilodaltons. The optimal assay conditions for the mengovirus-activated kinase paralleled those of the double-stranded RNA-activated PK (dsRNA-PK). Lysates from infected cells contained elements capable of activating partially purified dsRNA-PK. These elements were identified as double-stranded RNA by their sensitivity to double-stranded RNase. The phosphorylation of the alpha subunit of eIF-2 coincided with the synthesis of dsRNA in infected cells, suggesting that the mengovirus-activated kinase is the dsRNA-PK. The phosphorylation of the alpha subunit of eIF-2 correlated with the global inhibition of protein synthesis that occurs at late times after infection.
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Affiliation(s)
- J DeStefano
- Department of Molecular and Cell Biology, University of Connecticut, Storrs 06269-3125
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20
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Samuel CE, Brody MS. Biosynthesis of reovirus-specified polypeptides. 2-aminopurine increases the efficiency of translation of reovirus s1 mRNA but not s4 mRNA in transfected cells. Virology 1990; 176:106-13. [PMID: 2330670 DOI: 10.1016/0042-6822(90)90235-j] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The effect of 2-aminopurine (2AP), an inhibitor of the RNA-dependent P1/eIF-2 protein kinase, on the expression of the reovirus serotype 1 Lang strain S1 and S4 genes in transfected simian COS cells was examined. In the absence of 2AP, the s4-encoded sigma 3 gene product was expressed about five times more efficiently than the s1-encoded sigma 1 gene product. When COS cells were treated with 2AP, the synthesis of the sigma 1 polypeptide was increased about fivefold compared to that in untreated cells even though s1 mRNA levels were not detectably altered. In contrast to the increased translational efficiency of the s1 mRNA observed in 2AP-treated cells, the translational efficiency of the s4 mRNA was not affected by 2AP treatment. However, the cytoplasmic accumulation of s4 mRNA was transiently decreased by 2AP treatment. These results demonstrate that the expression of the reovirus S1 and S4 genes in transient transfection assays is differentially affected by 2AP. Furthermore, when considered together with the prior observation that the reovirus s1 mRNA is a potent activator of the RNA-dependent protein kinase relative to the s4 mRNA which is a very poor activator, the results are consistent with the suggestion that the differential translational efficiency of the reovirus s1 and s4 mRNAs in vivo may be attributed in part to their differential ability to activate the P1/eIF-2 protein kinase.
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Affiliation(s)
- C E Samuel
- Department of Biological Sciences, University of California, Santa Barbara 93106
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21
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O'Neill RE, Racaniello VR. Inhibition of translation in cells infected with a poliovirus 2Apro mutant correlates with phosphorylation of the alpha subunit of eucaryotic initiation factor 2. J Virol 1989; 63:5069-75. [PMID: 2555543 PMCID: PMC251168 DOI: 10.1128/jvi.63.12.5069-5075.1989] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
A poliovirus type 2 Lansing mutant was constructed by inserting 6 base pairs into the 2Apro region of an infectious cDNA clone, resulting in the addition of a leucine and threonine into the polypeptide sequence. The resulting small-plaque mutant, 2A-2, had a reduced viral yield in HeLa cells and synthesized viral proteins inefficiently. Infection with the mutant did not lead to specific inhibition of host cell protein synthesis early in infection, and this defect was attributed to a failure to induce cleavage of the cap-binding complex protein p220. At late times after infection with the mutant virus, both cellular and viral protein syntheses were severely inhibited. To explain this global inhibition of protein synthesis, the phosphorylation state of the alpha subunit of eucaryotic initiation factor 2 (eIF-2 alpha) was examined. eIF-2 alpha was phosphorylated in both R2-2A-2- and wild-type-virus-infected cells, indicating that poliovirus does not encode a function that blocks phosphorylation of eIF-2 alpha. The kinetics and extent of eIF-2 alpha phosphorylation correlated with the production of double-stranded RNA in infected cells, suggesting that eIF-2 alpha is phosphorylated by P1/eIF-2 alpha kinase. When HeLa cells were infected with R2-2A-2 in the presence of 2-aminopurine, a protein kinase inhibitor, much higher virus titers were produced, cleavage of p220 occurred, and host cell protein synthesis was specifically inhibited. Since phosphorylation of eIF-2 alpha was not inhibited by 2-aminopurine, we propose that 2-aminopurine rescues the ability of R2-2A-2 to induce cleavage of p220 by inhibition of a second as yet unidentified kinase.
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Affiliation(s)
- R E O'Neill
- Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
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22
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Hovanessian AG. The double stranded RNA-activated protein kinase induced by interferon: dsRNA-PK. JOURNAL OF INTERFERON RESEARCH 1989; 9:641-7. [PMID: 2481698 DOI: 10.1089/jir.1989.9.641] [Citation(s) in RCA: 162] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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23
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Gene induction by interferons and double-stranded RNA: selective inhibition by 2-aminopurine. Mol Cell Biol 1988. [PMID: 2460741 DOI: 10.1128/mcb.8.10.4289] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcription of several interferon-inducible human genes is also induced by double-stranded RNA. The nature and the mechanism of action of signals generated by interferons and by double-stranded RNA which mediate the induction of these genes are under investigation. Here we report that 2-aminopurine, a known inhibitor of protein kinases, could selectively block this induction process. Induction of mRNAs 561 and 6-16 in HeLaM cells by double-stranded RNA was completely inhibited by 10 mM 2-aminopurine, whereas cellular protein and RNA syntheses as well as the induction of metallothionein mRNA by CdCl2 were unaffected by this inhibitor. In addition, 2-aminopurine blocked the induction of the same two mRNAs and of mRNAs 2-5(A) synthetase, 2A, and 1-8 by alpha interferon and of mRNAs 2A and 1-8 by gamma interferon in HeLaM cells. The observed inhibition was at the level of transcription, and for establishing efficient inhibition, the 2-aminopurine treatment had to begin at early stages of interferon treatment. In GM2767 cells, 2-aminopurine inhibited induction of mRNAs 561 and 6-16 by double-stranded RNA but not by alpha interferon. These results suggest that double-stranded RNA-induced signal 2 is distinct from the interferon-alpha-induced signal 2 (R. K. Tiwari, J. Kusari, and G. C. Sen, EMBO J. 6:3373-3378, 1987) and that 2-aminopurine can block the former but not the latter. Moreover, it appeared that 2-aminopurine could block the production of signal 1 by interferons. This was confirmed by experiments in which we separately tested the effects of 2-aminopurine on signal 1 and signal 2 production by interferons in HeLaM cells. Although no direct experimental evidence is available as yet, our results are consistent with the hypothesis that the functioning of a protein kinase activity may be necessary for transcriptional induction of genes by double-stranded RNA and for gene induction by interferons in those cells in which signal 1 production is needed.
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24
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Tiwari RK, Kusari J, Kumar R, Sen GC. Gene induction by interferons and double-stranded RNA: selective inhibition by 2-aminopurine. Mol Cell Biol 1988; 8:4289-94. [PMID: 2460741 PMCID: PMC365501 DOI: 10.1128/mcb.8.10.4289-4294.1988] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Transcription of several interferon-inducible human genes is also induced by double-stranded RNA. The nature and the mechanism of action of signals generated by interferons and by double-stranded RNA which mediate the induction of these genes are under investigation. Here we report that 2-aminopurine, a known inhibitor of protein kinases, could selectively block this induction process. Induction of mRNAs 561 and 6-16 in HeLaM cells by double-stranded RNA was completely inhibited by 10 mM 2-aminopurine, whereas cellular protein and RNA syntheses as well as the induction of metallothionein mRNA by CdCl2 were unaffected by this inhibitor. In addition, 2-aminopurine blocked the induction of the same two mRNAs and of mRNAs 2-5(A) synthetase, 2A, and 1-8 by alpha interferon and of mRNAs 2A and 1-8 by gamma interferon in HeLaM cells. The observed inhibition was at the level of transcription, and for establishing efficient inhibition, the 2-aminopurine treatment had to begin at early stages of interferon treatment. In GM2767 cells, 2-aminopurine inhibited induction of mRNAs 561 and 6-16 by double-stranded RNA but not by alpha interferon. These results suggest that double-stranded RNA-induced signal 2 is distinct from the interferon-alpha-induced signal 2 (R. K. Tiwari, J. Kusari, and G. C. Sen, EMBO J. 6:3373-3378, 1987) and that 2-aminopurine can block the former but not the latter. Moreover, it appeared that 2-aminopurine could block the production of signal 1 by interferons. This was confirmed by experiments in which we separately tested the effects of 2-aminopurine on signal 1 and signal 2 production by interferons in HeLaM cells. Although no direct experimental evidence is available as yet, our results are consistent with the hypothesis that the functioning of a protein kinase activity may be necessary for transcriptional induction of genes by double-stranded RNA and for gene induction by interferons in those cells in which signal 1 production is needed.
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Affiliation(s)
- R K Tiwari
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021
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25
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Zinn K, Keller A, Whittemore LA, Maniatis T. 2-Aminopurine selectively inhibits the induction of beta-interferon, c-fos, and c-myc gene expression. Science 1988; 240:210-3. [PMID: 3281258 DOI: 10.1126/science.3281258] [Citation(s) in RCA: 206] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The protein kinase inhibitor 2-aminopurine (2AP) blocks the induction of the human beta-interferon gene by virus or poly(I)-poly(C) at the level of transcription. This inhibition is specific, since 2AP does not inhibit induction of either the hsp70 heat-shock gene by high temperature or the metallothionein gene by cadmium or dexamethasone. However, 2AP does block the induction of the c-fos and c-myc proto-oncogenes by serum growth factors or virus, suggesting that a protein kinase may be involved in the regulation of these genes, as well as of the beta-interferon gene. However, different factors must be required for the induction of these three genes, since they are not coordinately regulated by the same inducers in most of the cell lines examined.
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Affiliation(s)
- K Zinn
- Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, MA 02138
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26
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Sitikov AS, Simonenko PN, Shestakova EA, Ryazanov AG, Ovchinnikov LP. cAMP-dependent activation of protein synthesis correlates with dephosphorylation of elongation factor 2. FEBS Lett 1988; 228:327-31. [PMID: 2830143 DOI: 10.1016/0014-5793(88)80025-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The addition of 5 mM cAMP to a cell-free translation system from rabbit reticulocytes increases the rate of protein synthesis 3 5-fold. Lower concentrations of cAMP (0.005, 0.05 and 0.5 mM) have no effect on translation in this system. cAMP at all the concentrations tested stimulates the phosphorylation of the same pattern of polypeptides, while 5 mM cAMP additionally stimulates dephosphorylation of the 95 kDa polypeptide identified as elongation factor 2 (EF-2). Testing of the preparations of EF-2 with a different content of the phosphorylated form in poly(U)-directed poly(Phe) synthesis reveals that the EF-2 activity correlates with the fraction of non-phosphorylated EF-2. Thus cAMP-dependent activation of protein synthesis seems to be due to dephosphorylation of EF-2.
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Affiliation(s)
- A S Sitikov
- Institute of Protein Research, Academy of Sciences of the USSR, Pushchino, Moscow Region
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27
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Findeis MA, Whitesides GM. Protein synthesis in cell-free reticulocyte lysates on multi-hour incubation. Appl Biochem Biotechnol 1987; 15:169-89. [PMID: 3454128 DOI: 10.1007/bf02798447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cell-free protein synthesis in rabbit reticulocyte lysate translation mixtures has been studied during multi-hour incubations. In an impaired lysate obtained from cells stored at 0 degrees C before lysis, and showing a low initial rate of synthesis, translation could be stimulated by a factor of 4 by including RNase inhibitor and additional ATP and GTP. In translation mixtures prepared from normal lysates, protein synthesis could be improved by approximately 50% by the addition of excess GTP. The observed increases in protein synthesis were obtained by improved maintenance of the initial rate of synthesis.
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Affiliation(s)
- M A Findeis
- Department of Chemistry, Harvard University, Cambridge, MA 02138
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28
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Gross M, Redman R. Effect of antibody to the hemin-controlled translational repressor in rabbit reticulocyte lysate. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 908:123-30. [PMID: 3814599 DOI: 10.1016/0167-4781(87)90051-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We have examined the effect of the purified IgG from the serum of guinea pigs immunized with a highly purified preparation of rabbit reticulocyte, hemin-controlled translational repressor (HCR) on protein synthesis in the reticulocyte lysate. We have found that the anti-HCR (but not non-immune) IgG completely prevents or reverses the suppression of protein synthesis that occurs in hemin-deficient lysate, providing a direct and definitive demonstration that the inhibitory effect of hemin-deficiency is mediated solely by the activation of HCR. The anti-HCR IgG also prevents or reverses the phosphorylation of eIF-2 alpha and the reduced binding of Met-tRNAf to 40 S ribosomal subunits that accompanies the inhibition of protein synthesis in hemin-deficient lysate. In contrast, the anti-HCR IgG has no effect on the inhibition produced by low levels of double-stranded RNA (that is due to the activation of a separate protein kinase), but it does partly reverse inhibition due to oxidized glutathione, ethanol, and phosphatidylserine, indicating that the effect of these components is mediated, at least in part, by the activation of HCR. Finally, we have confirmed our earlier observation that an excess of proHCR, the inactive precursor of HCR, has little effect on the neutralization of HCR by limiting anti-HCR IgG, suggesting that the antigenic determinants on HCR are not exposed on ProHCR.
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29
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Adenovirus VAI RNA prevents phosphorylation of the eukaryotic initiation factor 2 alpha subunit subsequent to infection. Proc Natl Acad Sci U S A 1985; 82:4321-5. [PMID: 2989814 PMCID: PMC390405 DOI: 10.1073/pnas.82.13.4321] [Citation(s) in RCA: 138] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The virus-associated VAI RNA of adenovirus is a small, RNA polymerase III-transcribed species required for efficient translation of mRNAs late after infection. Deletion mutant dl331 fails to produce this RNA and, as a result, grows poorly. Three lines of evidence suggest that VAI RNA facilitates translation by preventing inactivation of the function of eukaryotic initiation factor 2 (eIF-2). First, the mutant's translational defect can be relieved by addition of eIF-2 or eIF-2B (GTP recycling factor). Second, extracts of mutant-infected cells exhibit enhanced protein P1/eIF-2 alpha subunit kinase activity. Third, dl331 can grow with nearly normal kinetics in cells that do not express the kinase.
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30
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Morley SJ, Jackson RJ. Preparation and properties of an improved cell-free protein synthesis system from mammalian liver. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 825:45-56. [PMID: 3995042 DOI: 10.1016/0167-4781(85)90078-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A cell-free protein synthesis system derived from mouse liver has been developed which faithfully translates endogenous and exogenous mRNA. The system is based on the unfractionated post-mitochondrial supernatant. The main measures taken to improve the activity of the system were: the use of high levels (30 mM) of creatine phosphate as an energy-generating system to counteract a hyperactive nucleoside triphosphatase activity in the extracts, the choice of homgenisation buffer, and the use of potassium acetate rather than KCl in the assay. The system exhibits a high initial rate of amino acid incorporation, and reinitiates translation on endogenous mRNA. Added tobacco mosaic virus (TMV) RNA is faithfully translated into full-length products at a rate of 60-80 amino acid residues per min at 30 degrees. The rate of overall amino acid incorporation slows after about 20 min and eventually ceases due to a failure in the re-initiation of translation, and not because of degradation of mRNA. Over a limited period of time, this improved cell-free translation system is comparable in activity to other eukaryotic systems generated to date, and should be useful in studies of the control of translation rates in mammalian liver.
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31
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Knoller S, Kaempfer R. Isolation of a heme-controlled inhibitor of translation that blocks the interaction between messenger rna and eukaryotic initiation factor 2. Biochemistry 1984; 23:2462-9. [PMID: 6477877 DOI: 10.1021/bi00306a022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A heme-controlled inhibitor of translation was isolated from the S-100 of rabbit reticulocytes by a novel procedure including chromatography on double-stranded ribonucleic acid (dsRNA)-cellulose. The inhibitor thus purified is extremely active and functionally resembles previously studied heme-controlled inhibitor preparations in terms of kinetics and extent of inhibition of translation, relief of inhibition by eukaryotic initiation factor 2 (eIF-2), relief of inhibition by 2-aminopurine, and preferential inhibition of alpha-over beta-globin synthesis. The action of this inhibitor on translation is resistant to treatment with bacterial alkaline phosphatase, micrococcal nuclease, or trypsin and to incubation at 95 degrees C, pH 2 or pH 12. The inhibitor not only is retained on DEAE-cellulose, phosphocellulose, and dsRNA-cellulose but also exhibits a high affinity for the dye Cibacron Blue, properties that suggest that it may be a protein. Unlike previously described heme-controlled inhibitor preparations, or preparations that did not pass over dsRNA-cellulose, the inhibitor recovered upon dsRNA-cellulose chromatography does not exhibit eIF-2 kinase activity. The inhibitor does not block ternary complex formation between eIF-2, methionyl-tRNAfMet, and GTP but inhibits the ability of eIF-2 to form a complex with labeled globin mRNA. In the presence of inhibitor, the formation of mRNA/eIF-2 complexes can be restored effectively by an excess of eIF-2 but not by an excess of mRNA. The inhibitor thus appears to block the interaction between eIF-2 and mRNA not by competing with eIF-2 for a binding site on mRNA but, instead, by acting on eIF-2 itself.(ABSTRACT TRUNCATED AT 250 WORDS)
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32
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De Benedetti A, Baglioni C. Phosphorylation of initiation factor eIF-2 alpha, binding of mRNA to 48 S complexes, and its reutilization in initiation of protein synthesis. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(17)43899-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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33
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Jackson RJ, Herbert P, Campbell EA, Hunt T. The roles of sugar phosphates and thiol-reducing systems in the control of reticulocyte protein synthesis. ACTA ACUST UNITED AC 1983; 131:313-24. [PMID: 6550533 DOI: 10.1111/j.1432-1033.1983.tb07264.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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34
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Jackson RJ, Campbell EA, Herbert P, Hunt T. The preparation and properties of gel-filtered rabbit-reticulocyte lysate protein-synthesis systems. EUROPEAN JOURNAL OF BIOCHEMISTRY 1983; 131:289-301. [PMID: 6832153 DOI: 10.1111/j.1432-1033.1983.tb07262.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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35
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36
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Siebert P, Hunziker W, Norman AW. Cell-free translation analysis of the vitamin D-dependent calcium binding protein mRNA activity present in total RNA and polysomal extracts from chick intestine. Arch Biochem Biophys 1982; 219:286-96. [PMID: 6187283 DOI: 10.1016/0003-9861(82)90159-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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37
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Robbins CH, Kramer G, Saneto R, Hardesty B, Johnson HM. Dissociation of protein kinase activity and the induction of the antiviral state in a cell line responsive to the antiviral effects of interferon. Biochem Biophys Res Commun 1981; 103:103-10. [PMID: 6172123 DOI: 10.1016/0006-291x(81)91666-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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38
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39
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Inglis MM, Newton AA. Comparison of the activities of HSV-1 and cellular mRNAs as templates for in vitro translation. Virology 1981; 110:1-15. [PMID: 6163251 DOI: 10.1016/0042-6822(81)90002-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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40
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Activity of eukaryotic initiation factor 2 is modified by processes distinct from phosphorylation. II. Activity of eukaryotic initiation factor 2 in lysate is modified by oxidation-reduction state of its sulfhydryl groups. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)69967-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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41
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Wu JM, Suhadolnik RJ. The effect of hemin, adenosine 3',5'-monophosphate and phosphorylated sugars on Met-tRNAfMet deacylase activity in rabbit reticulocyte lysates. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 609:392-9. [PMID: 6254566 DOI: 10.1016/0005-2787(80)90113-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The effect of hemin, phosphorylated sugars, adenosine 3',5'-monophosphate (cyclic AMP) and a number of purines on a specific initiator tRNA deacylase activity in rabbit reticulocytes has been investigated. In the concentration range established to be optimal for maximal stimulation of translation (5.5-30.0 microM), hemin produces a 20-82% inhibition of Met-tRNAfMet deacylation. In contrast, all phosphorylated sugars tested, with the exception of fructose 1,6-diphosphate, are without effect. High concentrations of cyclic AMP (2-4 mM) also significantly inhibit the deacylase activity. The role of hemin and Met-tRNAfMet deacylase in the control of peptide initiation are discussed.
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42
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43
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44
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45
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West DK, Baglioni C. Induction of interferon in HeLa cells of a protein kinase activated by double-stranded RNA. EUROPEAN JOURNAL OF BIOCHEMISTRY 1979; 101:461-8. [PMID: 520308 DOI: 10.1111/j.1432-1033.1979.tb19740.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Treatment of HeLa cells with human fibroblast interferon results in increased levels of latent protein kinase activity that can be activated by double-stranded RNA (dsRNA). The protein kinase activity in extracts of interferon-treated cells is assayed by two methods: (a) inhibition of protein synthesis in rabbit reticulocyte lysates and (b) phosphorylation of two polypeptides of Mr 72000 (P1) and 38000 (the eIF-2 alpha subunit of initiation factor 2). When extracts of interferon-treated cells are fractionated by centrifugation at 150000 x g, the protein kinase activity is found in the pellet fraction. The kinase is maximally activated by 0.1 micrograms/ml poly(I) . poly(C). An increase in protein kinase activity is detected after 8 h of treatment with 100 units interferon/ml or after a 17-h treatment with 12.5 units/ml or greater interferon concentrations. Therefore, the kinase activity increases as a function of both time of treatment and interferon concentration. Addition of actinomycin D to cells during interferon treatment prevents this increase. The protein kinase activity decreases gradually over three days when interferon-treated cells are subsequently grown in the absence of interferon.
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46
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Mumby M, Traugh JA. Dephosphorylation of translational initiation factors and 40S ribosomal subunits by phosphoprotein phosphatases from rabbit reticulocytes. Biochemistry 1979; 18:4548-56. [PMID: 227442 DOI: 10.1021/bi00588a015] [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: 12/13/2022]
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47
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Levin D, Ernst V, London I. Effects of the catalytic subunit of cAMP-dependent protein kinase (type II) from reticulocytes and bovine heart muscle on protein phosphorylation and protein synthesis in reticulocyte lysates. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(18)36036-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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48
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Cooper JA, Moss B. In vitro translation of immediate early, early, and late classes of RNA from vaccinia virus-infected cells. Virology 1979; 96:368-80. [PMID: 462811 DOI: 10.1016/0042-6822(79)90095-3] [Citation(s) in RCA: 114] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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49
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West DK, Lenz RJ, Baglioni C. Stimulation of protein synthesis and Met-tRNAf binding by phosphorylated sugars: studies on their mechanism of action. Biochemistry 1979; 18:624-32. [PMID: 420805 DOI: 10.1021/bi00571a012] [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: 12/15/2022]
Abstract
It has been previously reported by J. R. Lenz et al. [(1978) Biochemistry 17, 80--87] that certain phosphorylated sugars stimulate protein synthesis in extracts of mammalian cells. This effect was found to be due to a stimulation of Met-tRNAf binding to 40S ribosomal subunits, both in whole extracts and with isolated ribosomes. However, formation of a ternary complex of Met-tRNAf, initiation factor eIF-2, and GTP was not stimulated. It was also shown that the stimulation is not due solely to metabolism of the sugars. The present communication further characterizes the stimulatory effect of the sugars. They were found to prevent the inactivation of ribosomes that occurs during protein synthesis incubations. The sugars were also found to inhibit cAMP-dependent protein kinases noncompetitively. However, they stimulate Met-tRNAf binding to 40S ribosomal subunits even under conditions in which an inhibition of protein kinase has no effect. Although it has bot been possible to demonstrate a direct association of the sugars with the 40S initiation complex, the evidence suggests that their effect is mediated by an interaction with one of the components involved in the formation of this complex.
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Hovanessian AG, Kerr IM. The (2'-5') oligoadenylate (pppA2'-5'A2'-5'A) synthetase and protein kinase(s) from interferon-treated cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 1979; 93:515-26. [PMID: 217683 DOI: 10.1111/j.1432-1033.1979.tb12850.x] [Citation(s) in RCA: 159] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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