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Friend K, Brooks HA, Propson NE, Thomson JA, Kimble J. Embryonic Stem Cell Growth Factors Regulate eIF2α Phosphorylation. PLoS One 2015; 10:e0139076. [PMID: 26406898 PMCID: PMC4583406 DOI: 10.1371/journal.pone.0139076] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 09/09/2015] [Indexed: 12/18/2022] Open
Abstract
Growth factors and transcription factors are well known to regulate pluripotent stem cells, but less is known about translational control in stem cells. Here, we use embryonic stem cells (ESCs) to investigate a connection between ESC growth factors and eIF2α-mediated translational control (eIF2α phosphorylation promotes protein expression from mRNAs with upstream open-reading frames, or uORFs). We find abundant phosphorylated P-eIF2α (P-eIF2α) in both pluripotent mouse and human ESCs, but little P-eIF2α in ESCs triggered to differentiate. We show that the growth factors LIF (leukemia inhibitory factor) and BMP4 (bone morphogenic protein 4) both maintain P-eIF2α in mESCs, but use distinct mechanisms: LIF inhibits an eIF2α phosphatase whereas BMP4 activates an eIF2α kinase. The mRNAs encoding the pluripotency factors Nanog and c-Myc possess uORFs while Oct4 mRNA does not. We find that salubrinal, a chemical that increases eIF2α phosphorylation, promotes Nanog and c-Myc expression, but not Oct4 expression. These experiments connect ESC growth factors to eIF2α phosphorylation and suggest a chemical substitute for LIF to enhance Nanog and c-Myc expression.
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Affiliation(s)
- Kyle Friend
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, United States of America
- Department of Chemistry and Biochemistry, Washington and Lee University, Lexington, Virginia, 24450, United States of America
- * E-mail: (KF); (JK)
| | - Hunter A. Brooks
- Department of Chemistry and Biochemistry, Washington and Lee University, Lexington, Virginia, 24450, United States of America
| | - Nicholas E. Propson
- The Morgridge Institute for Research, 309 North Orchard Street, Madison, Wisconsin, 53715, United States of America
| | - James A. Thomson
- The Morgridge Institute for Research, 309 North Orchard Street, Madison, Wisconsin, 53715, United States of America
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706, United States of America
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, United States of America
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, 53706, United States of America
- * E-mail: (KF); (JK)
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Oka T, Tsuji H, Noda C, Sakai K, Hong YM, Suzuki I, Muñoz S, Natori Y. Isolation and characterization of a novel perchloric acid-soluble protein inhibiting cell-free protein synthesis. J Biol Chem 1995; 270:30060-7. [PMID: 8530410 DOI: 10.1074/jbc.270.50.30060] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We found a novel protein in the postmitochondria supernatant fraction of rat liver, which is soluble in 5% perchloric acid and strongly inhibits protein synthesis in a rabbit reticulocyte lysate system. The protein extracted from the supernatant fraction with 5% perchloric acid was purified by ammonium sulfate fractionation and CM-Sephadex chromatography. The protein was shown to consist of two identical subunits with a molecular mass of 14 kDa. By immunoscreening with the rabbit antisera against the protein, a cDNA encoding the protein was cloned and sequenced. The cDNA contained an open reading frame of 411 base pairs encoding a 136-amino acid protein with a molecular mass of 14,149 Da. The deduced amino acid sequence was completely identical with that constructed from all of the above peptides. Interestingly, the perchloric acid-soluble protein inhibited cell-free protein synthesis in the rabbit reticulocyte lysate system in a different manner from RNase A. The protein is likely to inhibit an initiation stage of cell-free protein synthesis. Among the rat tissues tested, the protein was located only in liver and kidney. These findings are the first report on a new inhibitor that may be involved in the regulation of protein synthesis in those tissues.
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Affiliation(s)
- T Oka
- Department of Nutrition, School of Medicine, University of Tokushima, Japan
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Chen JJ, Throop MS, Gehrke L, Kuo I, Pal JK, Brodsky M, London IM. Cloning of the cDNA of the heme-regulated eukaryotic initiation factor 2 alpha (eIF-2 alpha) kinase of rabbit reticulocytes: homology to yeast GCN2 protein kinase and human double-stranded-RNA-dependent eIF-2 alpha kinase. Proc Natl Acad Sci U S A 1991; 88:7729-33. [PMID: 1679235 PMCID: PMC52376 DOI: 10.1073/pnas.88.17.7729] [Citation(s) in RCA: 161] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have cloned the cDNA of the heme-regulated eIF-2 alpha kinase (HRI) of rabbit reticulocytes. In vitro translation of mRNA transcribed from the HRI cDNA yields a 90-kDa polypeptide that exhibits eIF-2 alpha kinase activity and is recognized by a monoclonal antibody directed against authentic HRI. The open reading frame sequence of the HRI cDNA contains all 11 catalytic domains of protein kinases with consensus sequences of protein-serine/threonine kinases in conserved catalytic domains VI and VIII. The HRI cDNA also contains an insert of approximately 140 amino acids between catalytic domains V and VI. The HRI cDNA coding sequence has extensive homology to GCN2 protein kinase of Saccharomyces cerevisiae and to human double-stranded-RNA-dependent eIF-2 alpha kinase. This observation suggests that GCN2 protein kinase may be an eIF-2 alpha kinase in yeast. In addition, HRI has an unusually high degree of homology to three protein kinases (NimA, Wee1, and CDC2) that are involved in the regulation of the cell cycle.
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Affiliation(s)
- J J Chen
- Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Cambridge
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Chen JJ, Pal JK, Petryshyn R, Kuo I, Yang JM, Throop MS, Gehrke L, London IM. Amino acid microsequencing of internal tryptic peptides of heme-regulated eukaryotic initiation factor 2 alpha subunit kinase: homology to protein kinases. Proc Natl Acad Sci U S A 1991; 88:315-9. [PMID: 1671169 PMCID: PMC50801 DOI: 10.1073/pnas.88.2.315] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have purified the heme-regulated eukaryotic initiation factor 2 alpha subunit (eIF-2 alpha) kinase (HRI) from rabbit reticulocytes for amino acid microsequencing. This kinase is a single 92-kDa polypeptide and migrates in perfect alignment with 32P-labeled HRI on SDS/PAGE. Its functions of binding ATP and of autophosphorylation and eIF-2 alpha phosphorylation are inhibited by hemin. The amino acid sequences of three tryptic peptides of HRI have been obtained. A search of the data base of the National Biomedical Research Foundation reveals that these amino acid sequences are unique and that two of these three sequences show homology to protein kinases. HRI peptide P-52 contains Asp-Phe-Gly, which is the most highly conserved short stretch of amino acids in catalytic domain VII of protein kinases. HRI peptide P-74 contains the conserved amino acid residues Asp-(Met)-Tyr-Ser-(Val)-Gly-Val found in catalytic domain IX of protein kinases [Hanks, S. K., Quinn, A. M. & Hunter, T. (1988) Science 241, 42-52]. These findings are consistent with the autokinase and eIF-2 alpha kinase activities of HRI. Synthetic HRI peptide P-74 is a very potent inhibitor of eIF-2 alpha phosphorylation by HRI. Since little is known about the function of conserved domain IX, P-74 peptide may be useful in elucidating the role of this domain of protein kinases.
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Affiliation(s)
- J J Chen
- Harvard-MIT Division of Health Sciences, Cambridge, MA 02139
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5
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Positive modulation of hemoglobin, heme, and transferrin receptor synthesis by murine interferon-alpha and -beta in differentiating Friend cells. Pivotal role of heme synthesis. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)52468-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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6
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Michelson AM, Ernst V, Levin DH, London IM. Effects of glucose 6-phosphate and hemin on activation of heme-regulated eIF-2 alpha kinase in gel-filtered reticulocyte lysates. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(17)39762-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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7
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Leroux A, London IM. Regulation of protein synthesis by phosphorylation of eukaryotic initiation factor 2 alpha in intact reticulocytes and reticulocyte lysates. Proc Natl Acad Sci U S A 1982; 79:2147-51. [PMID: 6954531 PMCID: PMC346147 DOI: 10.1073/pnas.79.7.2147] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Studies in intact rabbit reticulocytes and reticulocyte lysates provide further evidence of a functional role for the phosphorylation of eukaryotic initiation factor 2 alpha (eIF-2 alpha) in the regulation of initiation of protein synthesis in eukaryotic cells. In intact reticulocytes treated with isonicotinic acid hydrazide to inhibit heme synthesis, the phosphorylation of eIF-2 alpha was significantly greater than in control cells. In heme-deficient reticulocyte lysates and in lysates treated with double-stranded RNA, significant phosphorylation of eIF-2 alpha occurred prior to the onset of inhibition of protein synthesis; a large proportion, however, of the total eIF-2 alpha remained unphosphorylated. These findings indicate that a modest concentration of phosphorylated eIF-2 alpha can suffice to inhibit initiation, and they suggest that one of the factors with which eIF-2 must interact may be rate limiting, especially when eIF-2 alpha is phosphorylated.
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Gupta NK. Roles of eukaryotic initiation factor 2 ancillary factors in the regulation of eukaryotic protein synthesis initiation. CURRENT TOPICS IN CELLULAR REGULATION 1982; 21:1-33. [PMID: 6754267 DOI: 10.1016/b978-0-12-152821-8.50005-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Roy R, Ghosh-Dastidar P, Das A, Yaghmai B, Gupta N. Protein synthesis in rabbit reticulocytes. Co-eIF-2A reverses mRNA inhibition of ternary complex (Met-tRNAf.eIF-2.GTP) formation by eIF-2. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)69310-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Jagus R, Anderson WF, Safer B. The regulation of initiation of mammalian protein synthesis. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1981; 25:127-85. [PMID: 6164076 DOI: 10.1016/s0079-6603(08)60484-5] [Citation(s) in RCA: 228] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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12
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Amesz H, Goumans H, Haubrich-Morree T, Voorma HO, Benne R. Purification and characterization of a protein factor that reverses the inhibition of protein synthesis by the heme-regulated translational inhibitor in rabbit reticulocyte lysates. EUROPEAN JOURNAL OF BIOCHEMISTRY 1979; 98:513-20. [PMID: 488111 DOI: 10.1111/j.1432-1033.1979.tb13212.x] [Citation(s) in RCA: 103] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We have purified and partially characterized a supernatant factor which reverses the effect of the heme-regulated translational inhibitor on protein synthesis in rabbit reticulocyte lysates. The anti-inhibitor restores protein synthesis activity in heme deficient lysates (and in lysates to which the inhibitor has been added) to the level observed in the presence of heme. The factor has no effect on the phosphorylation of eIF-2 by the inhibitor nor on any reaction carried out with purified initiation factors. The anti-inhibitor probably consists of three subunits with molecular weights of 81000, 60000 and 41000. The factor is isolated from the postribosomal supernatant of rabbit reticulocytes both free and complexed to eIF-2. A possible mechanism of action is discussed.
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14
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Ranu RS, London IM. Regulation of protein synthesis in rabbit reticulocyte lysates: preparation of efficient protein synthesis lysates and the purification and characterization of the heme-regulated translational inhibitory protein kinase. Methods Enzymol 1979; 60:459-84. [PMID: 459912 DOI: 10.1016/s0076-6879(79)60045-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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15
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Ernst V, Levin D, London I. Evidence that glucose 6-phosphate regulates protein synthesis initiation in reticulocyte lysates. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34479-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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16
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REGULATION OF EUKARYOTIC PROTEIN CHAIN INITIATION BY PROTEIN KINASES AND HEME. Gene Expr 1978. [DOI: 10.1016/b978-0-08-022624-8.50009-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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17
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Freedman ML, Spieler PJ, Rosman J, Wildman JM. Cyclic AMP maintenance of rabbit reticulocyte haem and protein synthesis in the presence of ethanol and benzene. Br J Haematol 1977; 37:179-94. [PMID: 203310 DOI: 10.1111/j.1365-2141.1977.tb06834.x] [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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Lenz JR, Baglioni C. Haemin protects Met-tRNAf binding activity of isolated reticulocyte ribosomes from inactivation by protein kinase. Nature 1977; 266:191-3. [PMID: 859596 DOI: 10.1038/266191a0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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19
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Ranu RS, London IM. Regulation of protein synthesis in rabbit reticulocyte lysates: purification and initial characterization of the cyclic 3':5'-AMP independent protein kinase of the heme-regulated translational inhibitor. Proc Natl Acad Sci U S A 1976; 73:4349-53. [PMID: 1069987 PMCID: PMC431449 DOI: 10.1073/pnas.73.12.4349] [Citation(s) in RCA: 113] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The heme-regulated translational inhibitor (HRI) has been purified 4800-fold. On electrophoresis in sodium dodecyl sulfate/polyacrylamide gel, the purified HRI showed one major polypeptide band. The purified HRI inhibits protein synthesis in lysates containing optimal levels of hemin with inhibition kinetics which parallel those observed in heme-deficiency. Data are presented which are consistent with an enzymatic function of HRI in the inhibition of protein synthesis. The HRI is an adenosine 3':5'-cyclic monophosphate independent protein kinase which phosphorylates the small subunit (38,000) but not the large subunits (52,000 and 50,000) of the initiation factor which forms a ternary complex with Met-tRNAf and GTP. This evidence supports the hypothesis that inhibition of protein synthesis by HRI involves the phosphorylation of the initiation factor. These findings are discussed in relation to various models for the regulation of protein kinase activity by heme. (see article).
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20
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Cherbas L, London IM. On the mechanism of delayed inhibition of protein synthesis in heme-defecient rabbit reticulocyte lysates. Proc Natl Acad Sci U S A 1976; 73:3506-10. [PMID: 1068462 PMCID: PMC431145 DOI: 10.1073/pnas.73.10.3506] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In the absence of added hemin, protein synthesis in a rabbit reticulocyte lysate declines abruptly (shuts off) after about 5 min at 30 degrees. In these studies we have examined the basis for the lag period preceding shut-off. The initiation factor that binds Met-tRNAf, previously shown to be rate-limiting in inhibited, heme-deficient lysates, is found to be used stoichiometrically in the presence of excess inhibitor. We suggest that a principal effect of the inhibitor is to impair the recycling of the Met-tRNAf-binding factor; the lag period is attributable largely to the presence of a pool of excess Met-tRNAf-binding factor, which, once used in initiation, cannot be recycled because of the action of the inhibitor.
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21
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Ranu RS, Levin DH, Delaunay J, Ernst V, London IM. Regulation of protein synthesis in rabbit reticulocyte lysates: characteristics of inhibition of protein synthesis by a translational inhibitor from heme-deficient lysates and its relationship to the initiation factor which binds Met-tRNAf. Proc Natl Acad Sci U S A 1976; 73:2720-4. [PMID: 1066685 PMCID: PMC430720 DOI: 10.1073/pnas.73.8.2720] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In heme-deficient reticulocyte lysates a translational inhibitor which regulates protein synthesis is formed or activated. To define the mechanism of action of the translational inhibitor (RI), RI was partially purified. We have utilized the isolated RI to examine its relationship to the translational inhibitor formed in situ in heme-deficiency, some quantitative aspects of inhibition of protein synthesis, and the relationship of RI concentration to the initiation factor (IF-MP) which forms a ternary complex with Met-tRNAf and GTP (IF-MP-Met-tRNAf-GTP). The results demonstrate that the activity of isolated RI is related to the in situ heme-deficiency inhibitor by several criteria: (a) the biphasic kinetics of inhibition manifested by RI in lysates containing optimal levels of hemin are very similar to those observed in heme-deficiency, i.e., an initial period in which several rounds of protein synthesis proceed at the control rate followed by an abrupt decline in the rate of protein synthesis. (b) Both inhibitions are accompanied by the disaggreagation of polyribosomes with a concomitant increase in 80S ribosomes. (c) Both inhibitions are reversed by IF-MP. The isolated RI blocked protein synthesis in lysates at temperatures ranging from 15 degrees to 30 degrees. Although the rate of protein synthesis was a function of the temperature of incubation, the number of rounds of protein synthesis prior to shut-off was essentially the same at various temperatures. When RI was added to lysates, at increasing intervals after the start of incubation, the period of synthesis before shut-off (lag) progressively decreased. The inhibition of protein synthesis by RI was immediately reversed by the addition of IF-MP. The extent of reversal increased with increasing concentrations of IF-MP; at low levels of RI almost complete reversal of inhibition by IF-MP was obtained. However, at high levels of RI which did not appreciably increase the degree of inhibition of protein synthesis, equivalent amounts of IF-MP were less effective in reversing inhibition. These results suggest that the inhibition of protein synthesis by the isolated inhibitor involves the initiation factor IF-MP.
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Clemens MJ. Functional relationships between a reticulocyte polypeptide-chain-initiation factor (IF-MP) and the translational inhibitor involved in regulation of protein synthesis by haemin. EUROPEAN JOURNAL OF BIOCHEMISTRY 1976; 66:413-22. [PMID: 947756 DOI: 10.1111/j.1432-1033.1976.tb10531.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The rate of initiation of protein synthesis in rabbit reticulocyte lysates is regulated by a translational inhibitor protein which is activated in the absence of added haemin. The effects of this inhibitor on amino acid incorporation are overcome by the protein synthesis initiation factor IF-MP which binds Met-tRNAf in a ternary complex with GTP and which can transfer this complex to small ribosomal subunits. Addition of this factor to haemin-deficient lysates prevents loss of polysomes and regenerates polysomes from 80-S single ribosomes, thus confirming an effect at the level of polypeptide initiation. The ability of the initiation factor to overcome the effects of various concentrations of the translational inhibitor suggests that the inhibitor inactivates the factor catalytically rather than stoichiometrically. In a system in vitro consisting of salt-washed 40-S ribosomal subunits, initiator Met-tRNAf and GTP, the initiation factor IF-MP transfers Met-tRNAf to the subunits in the absence of any other factor or mRNA. Equilibrium buoyant density gradient analysis in CsCl shows that formaldehyde-fixed subunits carrying Met-tRNAf bound under these conditions have a buoyant density approximately 0.02 g/cm3 lower than the bulk of salt-washed subunits, suggesting that approximately 100000 daltons of additional protein are associated with these subunits. This is in marked contrast to the amounts of protein bound to subunits incubated with Met-tRNAf and GTP in the presence of a crude ribosomal salt-wash fraction. The translational inhibitor has no effect on formation of the ternary complex IF-MP-Met-tRNAf-GTP but does impair the factor-catalysed transfer of Met-tRNAf to washed subunits. The possible mechanisms of action of the inhibitor on polypeptide chain initiation are reviewed in the light of these results.
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Bonanou-Tzedaki SA, Arnstein HR. Subcellular localization of a lesion in protein synthesis in rabbit reticulocytes incubated at elevated temperatures. EUROPEAN JOURNAL OF BIOCHEMISTRY 1976; 61:397-407. [PMID: 1248466 DOI: 10.1111/j.1432-1033.1976.tb10033.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
When rabbit reticulocytes are incubated at 43-45 degrees C their rate of protein synthesis rapidly decreases, compared to a contol 37 degrees C incubation. Lysates prepared from cells incubated at this supra-optimal temperature have an equally decreased capacity for endogenous, but not poly(uridylic acid)-directed, protein synthesis. Subcellular fractionation traced the lesion to the crude ribosomal pellet, 0.5 M KCl ribosomal wash and postribosomal supernatant of the temperature-shocked cells. Preparation of purified ribosomal subparticles showed, however, that they were as active as the control in protein synthesis. In this paper we present evidence that the decreased activity of the heated lysate, 0.5 mM KCl wash and postribosomal supernatant is due to an inhibitor and can be overcome by the addition of 0.5 M KCl or supernatant from control cells. The results are discussed in terms of the inactivation of a component, essential for initiation of endogenous protein synthesis, which is probably partitioned between ribosomes and supernatant. We also suggest that the decreased protein synthetic activity of the heated cells may be related to their decreased synthesis of haem.
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Hardesty B, Kramer G, Cimadevilla M, Pinphanichakarn P, Konecki D. Translation level control in normal and leukemic cells. HAMATOLOGIE UND BLUTTRANSFUSION 1976; 19:531-40. [PMID: 1070462 DOI: 10.1007/978-3-642-87524-3_50] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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25
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Giloh H, Schochot L, Mager J. Inhibition of peptide chain initiation in lysates from ATP-depleted cells. II. Studies on the mechanism of the lesion and its relation to similar alterations caused by oxidized glutathione and hemin deprivation. BIOCHIMICA ET BIOPHYSICA ACTA 1975; 414:309-20. [PMID: 173394 DOI: 10.1016/0005-2787(75)90169-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The impairment of peptide chain initiation in lysates from ATP-depleted rabbit reticulocytes is accompanied by a loss of their ability to form the 40 S methionyl-tRNAfMet complex with a resultant failure to promote the AUG codon-dependent combination of the complex with the 60 S ribosomal subunit. These partial initiation reactions, as well as the overall protein-synthetic activity of the defective lysates could be restored by addition of a 0.5 M KC1 ribosomal extract or normal postribosomal supernatant or a 40-70% (NH4)2-SO4 fraction derived from it. Alternatively, reactivation of the impaired lysates could be achieved by supplementation with millimolar amounts of cyclic AMP or certain purine derivatives. The same subcellular fractions, as well as cyclic AMP or purine derivatives were also capable of overcoming the inhibition caused by incubating reticulocyte lysates in the presence of oxidized glutathione or in the absence of hemin. Severe intracellular ATP deprivation resulted in accumulation of a soluble translational inhibitor in the postribosomal fraction, thus resembling the parallel phenomenon described in hemin-deprived lysates. The striking similarities between the three kinds of inhibition studied by us point to an identical site of the underlying biochemical lesion, despite the different mechanisms mediating their induction.
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Gross M. Reversal of the inhibitory action of the hemin-controlled translational repressor by a post-ribosomal supernatant factor from rabbit reticulocyte lysate. Biochem Biophys Res Commun 1975; 67:1507-15. [PMID: 1201099 DOI: 10.1016/0006-291x(75)90197-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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27
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Cimadevilla JM, Kramer G, Pinphanichakarn P, Konecki D, Hardesty B. Inhibition of peptide chain initiation by a nonhemin-regulated translational repressor from Friend leukemia cells. Arch Biochem Biophys 1975; 171:145-53. [PMID: 1190790 DOI: 10.1016/0003-9861(75)90017-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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28
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Cimadevilla JM, Hardesty B. Evidence for a non-hemin regulated translational repressor in Friend leukemia virus transformed murine proerythroblasts. Biochem Biophys Res Commun 1975; 63:931-7. [PMID: 1131275 DOI: 10.1016/0006-291x(75)90658-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Clemens MJ, Safer B, Merrick WC, Anderson WF, London IM. Inhibition of protein synthesis in rabbit reticulocyte lysates by double-stranded RNA and oxidized glutathione: indirect mode of action on polypeptide chain initiation. Proc Natl Acad Sci U S A 1975; 72:1286-90. [PMID: 805425 PMCID: PMC432517 DOI: 10.1073/pnas.72.4.1286] [Citation(s) in RCA: 88] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
In the presence of added double-stranded RNA or oxidized glutathione, protein synthesis in heminsupplemented reticulocyte lysates declines abruptly after 8-12 min of incubation at 30 degrees. The kinetics of amino-acid incorporation are very similar to those seen when lysates incorporation are very similar to those seen when lysates are incubated in the absence of added hemin. The inhibitory effects of double-stranded RNA (dsRNA) and oxidized glutathione (GSSG) are partially overcome by a homogeneous initiation factor, IF-MP, which also stimulates protein synthesis in hemin-deficient lysates. This factor is involved in the binding of Met-tRNAfmet to 40S ribosomal subunits during protein chain initiation. However, neither dsRNA alone nor GSSG alone significantly inhibits formation of [40S subunit-Met-tRNAf] complexes induced in reticulocyte lysates by dsRNA or GSSG involves one or more components present in the lysates but absent from the fractionated in vitro system. Such components may be related to the translational inhibitor that is active in hemin-deficient lysates.
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Gross M. Control of globin synthesis by hemin. An intermediate form of the translational repressor in rabbit reticulocyte lysates. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 366:319-32. [PMID: 4425656 DOI: 10.1016/0005-2787(74)90292-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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33
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Hunter AR. Control of haemoglobin synthesis. Effect of iron deprivation in reticulocytes on the distribution of ribosomes on globin mRNAs. EUROPEAN JOURNAL OF BIOCHEMISTRY 1974; 47:509-16. [PMID: 4434993 DOI: 10.1111/j.1432-1033.1974.tb03719.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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34
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Beuzard Y, London IM. The effects of hemin and double-stranded RNA on alpha and beta globin synthesis in reticulocyte and Krebs II ascites cell-free systems and the relationship of these effects to an initiation factor preparation. Proc Natl Acad Sci U S A 1974; 71:2863-6. [PMID: 4528029 PMCID: PMC388572 DOI: 10.1073/pnas.71.7.2863] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Protein synthesis in reticulocyte lysates ceases abruptly in the absence of added hemin or in the presence of double-stranded RNA. A similar effect of double-stranded RNA is observed in Krebs II ascites cell-free systems translating exogenous globin mRNA. The shut-off of protein synthesis is due to inhibition of initiation and can be prevented or reversed by addition of the initiation factor preparation M(3). Preparations of M(1), M(2), and dissociation factor are ineffective under these conditions. The effects of added hemin, M(3), and globin mRNA on the synthesis of alpha and beta globin chains have been studied in the reticulocyte and ascites cell extracts. When the concentration of M(3) is rate limiting, the synthesis of beta chains exceeds that of alpha chains. When the concentration of mRNA is rate limiting, synthesis of alpha and beta chains is more nearly equal.
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Gross M. Isolation and characterization of an antibody to a highly purified preparation of the hemin-controlled translational repressor from rabbit reticulocytes. Biochem Biophys Res Commun 1974; 57:611-9. [PMID: 4133311 DOI: 10.1016/0006-291x(74)90590-7] [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: 01/09/2023]
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36
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Woodward WR, Herbert E. Preparation and characterization of an inhibitor of globin synthesis from the postribosomal supernatant of reticulocyte lysates. Methods Enzymol 1974; 30:731-40. [PMID: 4853741 DOI: 10.1016/0076-6879(74)30070-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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37
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38
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Regulation of Synthesis of Non-Globin Proteins in Cell-free Extracts of Rabbit Reticulocytes. J Biol Chem 1973. [DOI: 10.1016/s0021-9258(19)43961-6] [Citation(s) in RCA: 91] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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39
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Lodish HF. Biosynthesis of reticulocyte membrane proteins by membrane-free polyribosomes. Proc Natl Acad Sci U S A 1973; 70:1526-30. [PMID: 4514321 PMCID: PMC433535 DOI: 10.1073/pnas.70.5.1526] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Intact rabbit reticulocyte cells synthesize two predominant species of membrane polypeptides; at least 10 reticulocyte membrane polypeptide species are not produced by the cells. Cell-free extracts of reticulocytes, free of any membranes or membrane-bound polyribosomes, synthesize large amounts of these two membrane polypeptides; one of these polypeptides appears to be modified, probably by loss of 20-40 amino acids, after it is incorporated into the membrane. Deprivation of hemin results in inhibition of synthesis by lysates of membrane proteins, globin, and all other cytoplasmic proteins.
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40
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Gupta NK, Aerni RJ. Protein synthesis in rabbit reticulocytes: control of protein synthesis initiation by a met-tRNA Met f deacylase and peptide chain initiation factors. Biochem Biophys Res Commun 1973; 51:907-16. [PMID: 4703560 DOI: 10.1016/0006-291x(73)90013-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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41
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Beuzard Y, Rodvien R, London IM. Effect of hemin on the synthesis of hemoglobin and other proteins in mammalian cells. Proc Natl Acad Sci U S A 1973; 70:1022-6. [PMID: 4197926 PMCID: PMC433416 DOI: 10.1073/pnas.70.4.1022] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The initiation of globin synthesis in intact reticulocytes and in reticulocyte lysates is maintained by the addition of hemin. The specificity of this effect has been studied to determine whether it is restricted to hemoglobin and erythroid cells. In intact reticulocytes, hemin (500 muM) enhances the synthesis of carbonic anhydrase as well as of hemoglobin. Similar enhancement of protein synthesis is observed on addition of hemin (500 muM) to intact Krebs II ascites tumor cells, in cell-free extracts of these cells, added hemin (50 muM) increases endogenous protein synthesis and the translation of exogenous rabbit globin messenger RNA. These results provide evidence that the effect of hemin is not restricted to globin, and they suggest that hemin may enhance protein synthesis in at least some nonerythroid cells.
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42
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Gross M, Rabinovitz M. Control of globin synthesis by hemin. Effect of temperature on globin synthesis by the reticulocyte cell-free system and the activity of translational repressors formed in the absence of hemin. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 299:472-9. [PMID: 4699584 DOI: 10.1016/0005-2787(73)90272-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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43
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Rhoads RE, McKnight GS, Schimke RT. Quantitative Measurement of Ovalbumin Messenger Ribonucleic Acid Activity. J Biol Chem 1973. [DOI: 10.1016/s0021-9258(19)44182-3] [Citation(s) in RCA: 141] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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44
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Gross M, Rabinovitz M. Partial purification of a translational repressor mediating hemin control of globin synthesis and implication of results on the site of inhibition. Biochem Biophys Res Commun 1973; 50:832-8. [PMID: 4689080 DOI: 10.1016/0006-291x(73)91320-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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45
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Gross M, Rabinovitz M. Control of globin synthesis by hemin: factors influencing formation of an inhibitor of globin chain initiation in reticulocyte lysates. BIOCHIMICA ET BIOPHYSICA ACTA 1972; 287:340-52. [PMID: 4680051 DOI: 10.1016/0005-2787(72)90383-8] [Citation(s) in RCA: 122] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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46
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47
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Adamson SD, Yau PM, Herbert E, Zucker WV. Involvement of hemin, a stimulatory fraction from ribosomes and a protein synthesis inhibitor in the regulation of hemoglobin synthesis. J Mol Biol 1972; 63:247-64. [PMID: 4634507 DOI: 10.1016/0022-2836(72)90373-7] [Citation(s) in RCA: 86] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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48
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49
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Maxwell CR, Kamper CS, Rabinovitz M. Hemin control of globin synthesis: an assay for the inhibitor formed in the absence of hemin and some characteristics of its formation. J Mol Biol 1971; 58:317-27. [PMID: 5088932 DOI: 10.1016/0022-2836(71)90249-x] [Citation(s) in RCA: 119] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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50
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Balkow K, Korner A. Stimulation of haemoglobin synthesis in reticulocyte lysates by initiation factors. FEBS Lett 1971; 12:157-160. [PMID: 11945565 DOI: 10.1016/0014-5793(71)80057-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- K Balkow
- School of Biological Sciences, University of Sussex, Falmer, BN1 9QG, Sussex, England
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