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Komar AA, Merrick WC. A Retrospective on eIF2A-and Not the Alpha Subunit of eIF2. Int J Mol Sci 2020; 21:E2054. [PMID: 32192132 PMCID: PMC7139343 DOI: 10.3390/ijms21062054] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 02/29/2020] [Accepted: 03/13/2020] [Indexed: 12/31/2022] Open
Abstract
Initiation of protein synthesis in eukaryotes is a complex process requiring more than 12 different initiation factors, comprising over 30 polypeptide chains. The functions of many of these factors have been established in great detail; however, the precise role of some of them and their mechanism of action is still not well understood. Eukaryotic initiation factor 2A (eIF2A) is a single chain 65 kDa protein that was initially believed to serve as the functional homologue of prokaryotic IF2, since eIF2A and IF2 catalyze biochemically similar reactions, i.e., they stimulate initiator Met-tRNAi binding to the small ribosomal subunit. However, subsequent identification of a heterotrimeric 126 kDa factor, eIF2 (α,β,γ) showed that this factor, and not eIF2A, was primarily responsible for the binding of Met-tRNAi to 40S subunit in eukaryotes. It was found however, that eIF2A can promote recruitment of Met-tRNAi to 40S/mRNA complexes under conditions of inhibition of eIF2 activity (eIF2α-phosphorylation), or its absence. eIF2A does not function in major steps in the initiation process, but is suggested to act at some minor/alternative initiation events such as re-initiation, internal initiation, or non-AUG initiation, important for translational control of specific mRNAs. This review summarizes our current understanding of the eIF2A structure and function.
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Affiliation(s)
- Anton A. Komar
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological and Environmental Sciences, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA;
| | - William C. Merrick
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA;
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Studies on the mechanism of action of a eukaryotic codon-dependent factor specific for initiator Met-tRNAf and ribosomal 40 S subunits. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)34608-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Treadwell BV, Mauser L, Robinson WG. Initiation factors for protein synthesis from wheat germ. Methods Enzymol 1979; 60:181-93. [PMID: 459898 DOI: 10.1016/s0076-6879(79)60015-0] [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: 12/15/2022]
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Tewari S, Murray S, Noble EP. Studies on the effects of chronic ethanol ingestion on the properties of rat brain ribosomes. J Neurosci Res 1978; 3:375-87. [PMID: 739560 DOI: 10.1002/jnr.490030509] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Previous observations have demonstrated decreased in vivo and in vitro protein synthesis by brain ribosomal systems following long-term ethanol ingestion. For further investigation of the properties of brain ribosomes, the 40S and 60S ribosomal subunits were successfully isolated from control and chronic 10% ethanol-drinking rats. For a successful dissociation of ribosomes into subunits NH4Cl, puromycin and a high-salt treatment at 10 degrees C were essential with a critical concentration of Mg2+ since ribosomes could not be resolved at less than 7 mM Mg2+. Analysis of the A260 profile of the subunits on the sucrose gradients showed no significant differences between the control and ethanol-ingesting groups. Studies on 3H-labeled ribosomes following in vivo RNA labeling showed correspondence of the radioactive profiles from the incorporation of [5(-3) H) orotic acid into RNA with the sucrose gradient absorbance profile of 60S and 40S ribosomal subunits. Furthermore, active reassociation of both subunits occurred at 37 degrees C as demonstrated by the increased [14 C]-phenylalanine incorporation in the presence of poly(U). Results further showed that the poly(U)-dependent [14C]phenylalanine incorporation was significantly reduced by the subunits from the ethanol-ingesting animals. These findings suggest that long-term ingestion of ethanol caused functional changes in the properties of brain ribosomes, specifically on the reassociation process of the two subunits.
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Preobrazhensky AA, Spirin AS. Informosomes and their protein components: the present state of knowledge. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1978; 21:1-38. [PMID: 358275 DOI: 10.1016/s0079-6603(08)60265-2] [Citation(s) in RCA: 146] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Thompson HA, Sadnik I, Scheinbuks J, Moldave K. Studies on native ribosomal subunits from rat liver. Purification and characterization of a ribosome dissociation factor. Biochemistry 1977; 16:2221-30. [PMID: 861207 DOI: 10.1021/bi00629a028] [Citation(s) in RCA: 77] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A population of free, native ribosomal 40S subunits, that do not react with 60S subunits to form 80S ribosomes, has been identified in the postmicrosomal fraction of rat liver homogenates. A protein (IF-3) has been purified from high salt (0.88 M KCI) extracts of native 40S subunits by gradient centrifugation and by ammonium sulfate fractionation; it prevents the reassociation of subunits and to a limited extent dissociates ribosomes to subunits. The activity is measured by ultracentrifugation of the reaction products on linear sucrose gradients, or with an assay developed in this laboratory that couples dissociation with the 60S-specific peptidyltransferase reaction; the latter procedure measures the amount of 60S subunits released from ribosomes or remaining in incubations in the presence of IF-3. Dissociation factor activity is recovered from most of the particles that are resolved by zonal centrifugation of the total "native subunits" obtained from the postmicrosomal fraction; the highest concentration of IF-3, however, appears to be associated with native 40S subunits. The purified dissociation factor IF-3 is composed of about ten polypeptides and the molecular weight is estimated to be between 500 000 and 700 000, on the basis of glycerol and cesium chloride gradient centrifugation. When purified 40S subunits react with IF-3 or when 80S ribosomes are dissociated by IF-3, a product is formed which is dependent on the concentration of the protein factor and has the characteristics of a 40SIF-3 complex; centrifugation of the complex on sucrose and cesium chloride gradients suggests that the complex consists of 1 equiv of each of the two components. Although dissociation factor IF-3 appears to react in a specific manner with free or ribosome-associated 40S subunits, the reaction with subunits differs in several respects from that with ribosomes. The dissociation factor also appears to interact with 60S subunits but multiple complexes are formed, some with more than 1 IF-3 equiv per 60S particle. The IF-3 converts 40S dimers (55S particles) to the 40S-IF-3 complex and dissociates free, native 80S particles present in the postmicrosomal fraction, but it does not affect polysome-associated ribosomes engaged in protein synthesis.
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Spremulli LL, Walthall BJ, Lax SR, Ravel JM. Purification and properties of a Met-tRNAf binding factor from wheat germ. Arch Biochem Biophys 1977; 178:565-75. [PMID: 836045 DOI: 10.1016/0003-9861(77)90227-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Harbitz I, Hauge JG. Purification and properties of a methionine formylmethionyl-tRNA-binding initiation factor from pig liver. Arch Biochem Biophys 1976; 176:766-78. [PMID: 984854 DOI: 10.1016/0003-9861(76)90221-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Tiryaki D, Bermek E. On the mode of action of eucaryotic initiation factor 1. HOPPE-SEYLER'S ZEITSCHRIFT FUR PHYSIOLOGISCHE CHEMIE 1976; 357:721-6. [PMID: 964930 DOI: 10.1515/bchm2.1976.357.1.721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A factor isolated from the human tonsillar ribosomal wash specifically stimulated the poly (U)-dependent binding of Phe-tRNA to 40S subunits at low Mg2+ concentration and without any requirement for GTP. The stimulated binding of Phe-tRNA to 40S particles was inhibited in proportion to added deacylated tRNA. The factor was inactivated by N-ethylmaleimide, but in the presence of 40S subunits a considerable protection was observed. 40S subunits, incubated with the factor and isolated by centrifugation, carried significant factor activity. The results imply that the human tonsillar factor, which shows a great functional analogy to the eucaryotic initiation factor 1 from other sources, exerts its effect by an initial interaction with the 40S subunit.
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McCuiston J, Parker R, Moldave K. Partial purification and characterization of a binding factor specific for initiator tRNA and ribosomal 40S subunits and of an aminoacyl-tRNA hydrolase specific for 40S-bound Met-tRNAf from rat liver. Arch Biochem Biophys 1976; 172:387-98. [PMID: 1259415 DOI: 10.1016/0003-9861(76)90090-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Comolli R, Delpiano C, Schubert AC. Dependency on the source of supernatant factors for optimal 14C-polyphenylalanine synthesis by high-salt wash treated liver ribosomal subunits in rats of different ages. Exp Gerontol 1976; 11:5-10. [PMID: 1278270 DOI: 10.1016/0531-5565(76)90004-8] [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: 12/26/2022]
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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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Safer B, Adams SL, Anderson WF, Merrick WC. Binding of MET-TRNAf and GTP to homogeneous initiation factor MP. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)40695-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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17
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Purification and physical properties of homogeneous initiation factor MP from rabbit reticulocytes. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)40694-7] [Citation(s) in RCA: 120] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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18
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Adams SL, Safer B, Anderson WF, Merrick WC. Eukaryotic initiation complex formation. Evidence for two distinct pathways. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)40696-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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19
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Innanen VT, Nicholls DM. fMet-tRNA F Met binding and peptidyl transferase function in free and bound ribosomes from normal and puromycin aminonucleoside-treated rats. Chem Biol Interact 1975; 11:431-9. [PMID: 1192550 DOI: 10.1016/0009-2797(75)90010-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Treatment of rats with the aminonucleoside of puromycin, which increases the incorporation of labelled phenylalanyl-tRNA into polypeptide chains in liver ribosome preparations studied in vitro, did not change the factor-dependent binding of fMet-tRNA f Met to ribosomes nor the peptidyl transferase function of the ribosomes. Peptidyl transferase function, as measured by fMet-tRNA f Met-puromycin formation, was comparable in the free and bound ribosome preparations. Similarly, the factor-dependent binding of fMet-tRNA f Met to ribosomes was the same in free ribosome preparations obtained from rat liver as it was in bound ribosome preparations that had been freed of membranes by puromycin incubation and high salt wash.
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Filipowicz W, Sierra JM, Ochoa S. Polypeptide chain initiation in eukaryotes: initiation factor MP in Artemia salina embryos. Proc Natl Acad Sci U S A 1975; 72:3947-51. [PMID: 1105571 PMCID: PMC433114 DOI: 10.1073/pnas.72.10.3947] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The activity of IF-MP, a polypeptide chain initiation factor that forms a ternary complex with eukaryotic initiator Met-tRNA and GTP and promotes binding of the initiator to 40S ribosomes, is very low in undeveloped Artemia salina embryos but increases over 20-fold following resumption of development upon hydration of the cysts. The factor is present in both the ribosomal salt wash and high-speed-supernatant. Its specific activity is 50 times higher in the wash but its total activity is only about twice as high in the wash as in the supernatant. As is true of IF-MP from other eukaryotic sources, the A. salina factor is specific for eukaryotic Met-tRNAi and sensitive to SH-reagents, and its activity is GTP dependent.
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21
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Wells GN, Beevers L. Protein synthesis in the cotyledons of Pisum sativum L. Messenger RNA-independent formation of a methionyl-tRNA initiation complex. Arch Biochem Biophys 1975; 170:384-91. [PMID: 1190771 DOI: 10.1016/0003-9861(75)90133-2] [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: 12/26/2022]
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22
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Cimadevilla JM, Hardesty B. Isolation and partial characterization of a 40 S ribosomal subunit-transfer ribonucleic acid binding factor from rabbit reticulocytes. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)41314-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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23
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Comparison of fMet-tRNAf and Met-tRNAf from Escherichia coli and rabbit liver in initiation of hemoglobin synthesis. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)41596-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Merrick WC, Anderson WF. Purification and characterization of homogeneous protein synthesis initiation factor M1 from rabbit reticulocytes. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)41799-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Gupta NK, Chatterjee B, Chen YC, Majumdar A. Protein synthesis in rabbit reticulocytes. A study of Met-tRNA f Met binding factor(s) and Met-tRNA f Met binding to ribosomes and AUG codon. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)41864-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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26
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Hubert C, Baliga BS, Villee CA, Munro HN. Protein synthesis in a cell-free system prepared from human placenta. II. pH 5 enzyme inefficiency due to defects in tRNA charging with resulting loss of elongation factor 1. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 374:359-74. [PMID: 4611498 DOI: 10.1016/0005-2787(74)90257-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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27
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Scheinbuks J, Sypherd PS, Moldave K. Studies on the structure and function of ribosomes from regenerating rat liver. Biochem Biophys Res Commun 1974; 61:322-8. [PMID: 4441400 DOI: 10.1016/0006-291x(74)90569-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Steinert PM, Baliga BS, Munro HN. Available sulphydryl groups of mammalian ribosomes in different functional states. J Mol Biol 1974; 88:895-911. [PMID: 4427385 DOI: 10.1016/0022-2836(74)90406-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Grummt F. Studies on two initiation factors of protein synthesis from rat-liver cytoplasm. EUROPEAN JOURNAL OF BIOCHEMISTRY 1974; 43:337-42. [PMID: 4599285 DOI: 10.1111/j.1432-1033.1974.tb03417.x] [Citation(s) in RCA: 26] [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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Wells GN, Beevers L. Protein synthesis in the cotyledons of Pisum sativum L. Protein factors involved in the binding of phenylalanyl-transfer ribonucleic acid to ribosomes. Biochem J 1974; 139:61-9. [PMID: 4463949 PMCID: PMC1166251 DOI: 10.1042/bj1390061] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
1. Proteinaceous factors contained in a 0.5m-KCl extract of ribosomes from pea cotyledons form a ternary complex at 0 degrees C with [(14)C]phenylalanyl-tRNA and poly(U). The complex is measured by its quantitative retention on Millipore filters. 2. Complex-assembly is optimal at 5mm-Mg(2+) and is independent of GTP and ribosomes. 3. The addition of ribosomes is required to stabilize the complex at 34 degrees C. The complex binds to a puromycin-sensitive site on the ribosome. 4. Soluble factors from the 250000g supernatant of pea cotyledon form a Millipore-retainable complex dependent on GTP and ribosomes. 5. Complex-formation by soluble factors has a Mg(2+) optimum of 10-12mm and forms a puromycin-insensitive complex with ribosomes. 6. The function of the ribosomal protein factors and the supernatant fraction in initiation of protein synthesis is discussed.
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Cimadevilla JM, Morrisey J, Hardesty B. A functional interaction between methionyl-transfer RNA hydrolase and a transfer RNA binding factor. J Mol Biol 1974; 83:437-46. [PMID: 4830855 DOI: 10.1016/0022-2836(74)90505-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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32
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Grove BK, Johnson TC, Gilbert BE. Thermostability of mammalian brain ribosomes and the effects of nucleoside triphosphates on their heat-sensitivity. Biochem J 1974; 137:291-8. [PMID: 4596142 PMCID: PMC1166116 DOI: 10.1042/bj1370291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Mammalian brain ribosomes were found to be heat-labile. On preincubation of the ribosomes at 37 degrees C, their ability to participate in polypeptide-synthesis reactions was substantially diminished. Despite the sensitivity of ribosomal protein synthesis to heat-inactivation, preincubation resulted in no significant alterations in ribosomal sedimentation profiles or changes in the integrity of the ribosomal RNA. The thermolability of brain ribosomes was shown to be associated with their inability to bind both template RNA and aminoacyl-tRNA. Similar experiments with brain ribosomal subunits demonstrated that the small (40S) subunit was more sensitive to heat-inactivation than the large (60S) subunit. The presence of ATP (1mm) protected ribosomes from thermal inactivation, although this protection was shown to be temporary. The protection appeared to be specific to nucleoside triphosphates, since GTP and UTP also stabilized ribosomes to thermal denaturation whereas nucleoside diphosphates (ADP) and nucleoside monophosphates (AMP and cyclic AMP) did not alter ribosomal sensitivity to heat. Although 1mm concentrations of nucleoside triphosphates protected ribosomes from heat-inactivation, the presence of higher concentrations resulted in complete inactivation of ribosomal activity.
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Cimadevilla JM, Hardesty B. Assay and isolation of a 40 S ribosomal subunit-Met-tRNAfMet binding factor from rabbit reticulocytes. Methods Enzymol 1974; 30:206-15. [PMID: 4850660 DOI: 10.1016/0076-6879(74)30023-7] [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: 01/12/2023]
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Leader DP, Wool IG. Isolation, purification, and assay of an initiation factor from rat liver cytosol that promotes binding of aminoacyl-tRNA to 40 S ribosomal subunits. Methods Enzymol 1974; 30:180-6. [PMID: 4852601 DOI: 10.1016/0076-6879(74)30020-1] [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: 01/12/2023]
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Woodley CL, Chen YC, Gupta NK. Purification and properties of the peptide chain initiation factors from rabbit reticulocytes. Methods Enzymol 1974; 30:141-53. [PMID: 4604997 DOI: 10.1016/0076-6879(74)30017-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Ochoa S, Mazumder R. 1. Polypeptide Chain Initiation. ACTA ACUST UNITED AC 1974. [DOI: 10.1016/s1874-6047(08)60133-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
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37
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Zasloff M, Ochoa S. Purification of eukaryotic initiation factor 1 (EIF1) from Artemia salina embryos. Methods Enzymol 1974; 30:197-206. [PMID: 4853976 DOI: 10.1016/0076-6879(74)30022-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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38
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Gilbert BE, Johnson TC. Mouse brain ribosomal subunits: role of ribosome-associated factors on aminoacyl-tRNA binding and polypeptide synthesis. Brain Res 1973; 63:313-22. [PMID: 4764301 DOI: 10.1016/0006-8993(73)90098-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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40
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Ayuso-Parilla M, Hirsch CA, Henshaw EC. Release of the Nonribosomal Proteins from the Mammalian Native 40 S Ribosomal Subunit by Aurintricarboxylic Acid. J Biol Chem 1973. [DOI: 10.1016/s0021-9258(19)43783-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Andron LA, Strehler BL. Recent evidence on tRNA and tRNA acylase-mediated cellular control mechanisms: a review. Mech Ageing Dev 1973; 2:97-116. [PMID: 4199831 DOI: 10.1016/0047-6374(73)90009-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Pain VM, Clemens MJ. The role of soluble protein factors in the translational control of protein synthesis in eukaryotic cells. FEBS Lett 1973; 32:205-12. [PMID: 4582153 DOI: 10.1016/0014-5793(73)80834-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Nicholls DM. Increased translation in liver involves a supernatant factor following laser irradiation. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 308:168-79. [PMID: 4579083 DOI: 10.1016/0005-2787(73)90134-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Zasloff M, Ochoa S. Polypeptide chain initiation in eukaryotes. IV. Purification and properties of supernatant initiation factor from Artemia salina embryos. J Mol Biol 1973; 73:65-76. [PMID: 4690308 DOI: 10.1016/0022-2836(73)90159-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Schroer RA, Moldave K. Interaction of rat liver ribosomal subunits with homologous Met-tRNAs. Arch Biochem Biophys 1973; 154:422-30. [PMID: 4689785 DOI: 10.1016/0003-9861(73)90075-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Schroer RA, Moldave K. Factor-independent interaction of met-tRNA i and ApUpG with 40 S subunits of rat liver ribosomes. Biochem Biophys Res Commun 1972; 48:1572-7. [PMID: 5077837 DOI: 10.1016/0006-291x(72)90893-5] [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: 01/13/2023]
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McCroskey RP, Zasloff M, Ochoa S. Polypeptide chain initiation and stepwise elongation with Artemia ribosomes and factors. Proc Natl Acad Sci U S A 1972; 69:2451-5. [PMID: 4560686 PMCID: PMC426963 DOI: 10.1073/pnas.69.9.2451] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The supernatant initiation factor from Artemia salina embryos promotes, besides the AUG-dependent binding of fMet-tRNA(f), the poly(U)-dependent binding of N-acetylPhe-tRNA to 40S ribosomal subunits; the bound N-acylaminoacyl-tRNA reacts directly with puromycin upon addition of 60S subunits. Both the binding reaction and the synthesis of N-acylaminoacyl-puromycin occur in the absence of GTP or other ribonucleoside triphosphates. To a smaller extent, the factor also mediates the 40S ribosomal binding of Met-tRNA(f) and Phe-tRNA; in this case, the bound aminoacyl-tRNA is less reactive with puromycin. After the poly(U)- and supernatant factor-dependent binding of N-acetylPhe-tRNA to 40S subunits at low Mg(2+) concentration, binding of a second aminoacyl-tRNA (Phe-tRNA), with ensuing formation of the first peptide bond, is dependent upon the addition of the 60S subunit, elongation factor EF-1, and GTP. Further growth of the polypeptide chain requires translocation and is, therefore, dependent upon the addition of elongation factor EF-2. As with the Escherichia coli system, once requirements for translation of the third codon have been met, no further additions are necessary for elongation of a peptide chain.
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