1
|
Caraglia M, Budillon A, Vitale G, Lupoli G, Tagliaferri P, Abbruzzese A. Modulation of molecular mechanisms involved in protein synthesis machinery as a new tool for the control of cell proliferation. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:3919-36. [PMID: 10866791 DOI: 10.1046/j.1432-1327.2000.01465.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the past years, the attention of scientists has focused mainly on the study of the genetic information and alterations that regulate eukaryotic cell proliferation and that lead to neoplastic transformation. All therapeutic strategies against cancer are, to date, directed at DNA either with cytotoxic drugs or gene therapy. Little or no interest has been aroused by protein synthesis mechanisms. However, an increasing body of data is emerging about the involvement of translational processes and factors in control of cell proliferation, indicating that protein synthesis can be an additional target for anticancer strategies. In this paper we review the novel insights on the biochemical and molecular events leading to protein biosynthesis and we describe their involvement in cell proliferation and tumorigenesis. A possible mechanistic explanation is given by the interactions that occur between protein synthesis machinery and the proliferative signal transduction pathways and that are therefore suitable targets for indirect modulation of protein synthesis. We briefly describe the molecular tools used to block protein synthesis and the attempts made at increasing their efficacy. Finally, we propose a new multimodal strategy against cancer based on the simultaneous intervention on protein synthesis and signal transduction.
Collapse
Affiliation(s)
- M Caraglia
- Dipartimento di Biochimica e Biofisica, Seconda Università di Napoli, Italy
| | | | | | | | | | | |
Collapse
|
2
|
Affiliation(s)
- C G Proud
- Department of Biochemistry, School of Medical Sciences, University of Bristol, England
| |
Collapse
|
3
|
Bader M, Sarre TF. Characterization of an inhibitor of protein synthesis initiation from mouse erythroleukemia cells. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 1009:61-9. [PMID: 2790031 DOI: 10.1016/0167-4781(89)90079-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This study describes the partial purification of a translational inhibitor from mouse erythroleukemia (MEL) cells. It is present in MEL cells induced to erythroid differentiation and in uninduced cells in approximately equal amounts. The inhibitor blocks initiation but not elongation of in vitro protein synthesis in the rabbit reticulocyte lysate and in extracts prepared from induced or uninduced MEL cells. Nuclease-resistance, heat-sensitivity and the chromatographic behaviour of the inhibitor indicate that it is a protein with a relative molecular mass of approx. (45-70).10(3). The inhibitor has no eIF-2 alpha phosphorylating activity and does not affect the formation of the ternary complex [eIF-2.GTP.Met-tRNAf] nor the binding of Met-tRNAf to the 40 S ribosomal subunit. The inhibitor interferes with the binding of mRNA to the 43 S preinitiation complex, independent of the presence of the m7GTP cap of the mRNA.
Collapse
Affiliation(s)
- M Bader
- Institut für Biologie III, Freiburg, F.R.G
| | | |
Collapse
|
4
|
Sarre TF, Hermann M, Bader M. Differential effect of hemin-controlled eIF-2 alpha kinases from mouse erythroleukemia cells on protein synthesis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 183:137-43. [PMID: 2753041 DOI: 10.1111/j.1432-1033.1989.tb14905.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cultured mouse erythroleukemia (MEL) cells can be induced to erythroid differentiation by a variety of chemical agents. This differentiation process is marked by the onset of globin mRNA and hemoglobin synthesis. In rabbit reticulocytes, globin synthesis is regulated by a hemin-controlled translational inhibitor (HCI) which acts via phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF-2). From both uninduced and induced MEL cells, hemin-controlled eIF-2 alpha kinases have been partially purified. They resemble HCI with respect to their chromatographic behaviour and their sensitivity towards physiological concentrations of hemin (5-10 microM). Further purification on phosphocellulose, however, reveals that the eIF-2 alpha kinase from uninduced MEL cells is chromatographically distinct from HCI, whilst the eIF-2 alpha kinase activity from induced MEL cells represents a mixture of the former and the HCI-type eIF-2 alpha kinase. The latter inhibits protein synthesis in a fractionated system from rabbit reticulocytes which is free of, but sensitive to, HCI, whereas the eIF-2 alpha kinase from uninduced MEL cells does not show any inhibitory activity. This observation is supported by the finding that induced MEL cells respond in vivo to iron depletion with a shut-off of protein synthesis (as do rabbit reticulocytes), whilst uninduced MEL cells do not.
Collapse
Affiliation(s)
- T F Sarre
- Institut für Biologie III, Universität Freiburg im Breisgau, Federal Republic of Germany
| | | | | |
Collapse
|
5
|
Rose DW, Welch WJ, Kramer G, Hardesty B. Possible Involvement of the 90-kDa Heat Shock Protein in the Regulation of Protein Synthesis. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)83339-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
6
|
Sarre TF. The phosphorylation of eukaryotic initiation factor 2: a principle of translational control in mammalian cells. Biosystems 1989; 22:311-25. [PMID: 2679904 DOI: 10.1016/0303-2647(89)90053-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In eukaryotic cells, protein biosynthesis is controlled at the level of polypeptide chain initiation. During the initiation process, eukaryotic initiation factor 2 (eIF-2) catalyzes the binding of Met-tRNAf and GTP to the 40S ribosomal subunit. In a later step, eIF-2 is released from the ribosomal initiation complex, most likely as an eIF-2.GDP complex, and another initiation factor termed eIF-2B is necessary to recycle eIF-2 by displacing GDP by GTP. In rabbit reticulocytes, inhibition of protein synthesis is accompanied by the phosphorylation of the alpha-subunit of eIF-2, a process that does not render eIF-2 inactive, but prevents it from being recycled by eIF-2B. First described in rabbit reticulocytes as inhibitors of translation, two distinct eIF-2 alpha kinases are known: the haemin-controlled kinase (termed HCI) and the double-stranded RNA-activated kinase (termed DAI). eIF-2 alpha phosphorylation appears to be a reversible control mechanism since corresponding phosphatases have been described. Recent reports indicate a correlation between eIF-2 alpha phosphorylation and the inhibition of protein synthesis in several mammalian cell types under a range of physiological conditions. In this review, the physical and functional features of the known eIF-2 alpha kinases are described with respect to their role in mammalian cells and the mode of activation by cellular signals. Furthermore, the possible impact of the eIF-2/eIF-2B ratio and of the subcellular compartmentation of these factors (and the eIF-2 alpha kinases) on mammalian protein synthesis is discussed.
Collapse
Affiliation(s)
- T F Sarre
- Institut für Biologie III, Freiburg, F.R.G
| |
Collapse
|
7
|
Bader M, Sarre TF. A (re)initiation-dependent cell-free protein-synthesis system from mouse erythroleukemia cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 1986; 161:103-9. [PMID: 2430803 DOI: 10.1111/j.1432-1033.1986.tb10129.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cultured mouse erythroleukemia cells (MEL cells) can be induced in vivo to erythroid differentiation which is marked by the onset of globin mRNA and haemoglobin synthesis. When these cells are briefly exposed to hypertonic growth medium prior to lysis, the resulting post-mitochondrial supernatants show a high in vitro protein-synthesis activity. Amino acid incorporation is linear up to 60 min; more than 80% of this is due to (re)initiation, as shown by the inhibition with edeine. Extracts from induced cells reach only a third of overall incorporation as compared to extracts from uninduced cells. This reduction of the protein-synthesizing capacity is also observed in vivo. Polyacrylamide gel electrophoresis shows that extracts from uninduced cells faithfully translate their endogenous mRNA, whereas in extracts from induced cells, non-globin protein synthesis is reduced and globin is preferentially synthesized. Haemin (40 microM) as well as purified eukaryotic initiation factor 2 (eIF-2) from rabbit reticulocytes enhance amino acid incorporation in both kinds of extracts, which suggests that both uninduced and induced MEL cells contain a haemin-controlled eIF-2 alpha kinase. This system should be useful for studying the mechanisms controlling protein synthesis in a nucleated differentiating cell.
Collapse
|
8
|
Wettenhall RE, Kudlicki W, Kramer G, Hardesty B. The NH2-terminal sequence of the alpha and gamma subunits of eukaryotic initiation factor 2 and the phosphorylation site for the heme-regulated eIF-2 alpha kinase. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)67107-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
9
|
Lorberboum H, Galski H, Scharf C, Weinstein D, de Groot N, Hochberg AA. Alkaline phosphatase and protein kinase(s) activities in free cytoplasmic mRNPs from human term placenta. Mol Biol Rep 1986; 11:29-35. [PMID: 3945233 DOI: 10.1007/bf00417592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Free mRNPs isolated from human term placental tissue were examined for protein kinase and phosphoprotein-phosphatase activities. Free mRNPs incubated with [gamma-32P]ATP in a protein kinase standard buffer show self-phosphorylation in the absence of exogenous substrates. Treatment of phosphorylated products with alkali showed a significant phosphorylation of tyrosine residues within the mRNP-proteins. An alkaline-phosphatase activity was found to be tightly associated with the mRNPs. Both heat stable and heat labile alkaline phosphatase activities were found in the mRNPs. Heat labile alkaline phosphatase is the major isoenzyme form of the mRNPs. The existence of both protein kinase(s) and alkaline phosphatase activities in placental free cytoplasmic mRNPs might suggest that a balance between phosphorylation, specifically on tyrosine residues, and dephosphorylation states of some of the mRNP-proteins is relevant for their physiological functions, and may therefore play a role in the regulation of mRNPs' metabolism and, consequently, in mRNA translation.
Collapse
|
10
|
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.
Collapse
|
11
|
Wahba AJ, Woodley CL. Molecular aspects of development in the brine shrimp Artemia. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1984; 31:221-65. [PMID: 6397772 DOI: 10.1016/s0079-6603(08)60379-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
12
|
|
13
|
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]
|
14
|
Fuchs O, Ponka P, Borova J, Neuwirt J, Travnicek M. Effect of heme on globin messenger RNA synthesis in spleen erythroid cells. JOURNAL OF SUPRAMOLECULAR STRUCTURE AND CELLULAR BIOCHEMISTRY 1981; 15:73-81. [PMID: 6166793 DOI: 10.1002/jsscb.1981.380150108] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Synthesis of globin mRNA in erythroid spleen cells from anemic mice was measured after in vitro incubation under conditions in which the level of intracellular heme was manipulated. This newly synthesized globin mRNA was isolated by hybridization with globin cDNA covalently bound to cellulose. Isonicotinic acid hydrazide (INH) and penicillamine were used as specific inhibitors of heme synthesis. It has been found that a 120-min incubation of spleen erythroid cells with 5mM INH or 5mM penicillamine reduced [3H] uridine incorporation into globin mRNA by 24% or 36%, respectively. The addition of heme to INH- or penicillamine-treated cells almost completely restored [3H] uridine incorporation into globin mRNA. These results indicate that heme stimulates transcription of processing of globin mRNA.
Collapse
|
15
|
Bag J, Sells BH. Presence of cyclic-AMP-independent protein kinase activity in RNA-binding proteins of embryonic chicken muscle. EUROPEAN JOURNAL OF BIOCHEMISTRY 1980; 106:411-24. [PMID: 6156824 DOI: 10.1111/j.1432-1033.1980.tb04587.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
16
|
Abstract
Synthesis of globin in reticulocyte lysates depends on the presence of heme, the prosthetic group of hemoglobin. In the absence of heme, an inhibitor of polypeptide chain initiation is activated. The inhibitor is a cyclic AMP-independent protein kinase that catalyzes the phosphorylation by ATP of the small subunit of the initiation factor eIF-2. This blocks the interaction of eIF-2 with eIF-2-stimulating protein (ESP) that is essential for initiation. Our observations are consistent with the view that the inhibitor is activated by phosphorylation catalyzed by a cyclic AMP-dependent protein kinase. Heme inhibits this enzyme and, in this way, prevents activation of the inhibitor of chain initiation.
Collapse
|
17
|
Abstract
Information has been collected to stimulate interest regarding the nature and the possible role of mRNP protein phosphorylation in a cytoplasmic control mechanism for protein synthesis. It does not imply a direct relationship between mRNP protein and initiation factors. These proteins have some properties in common (e.g. molecular weight, phosphorylation, protein kinase, mRNA binding activity). We emphasize that some free mRNP may be translatable after modification of their protein by interference factors belonging to other cellular compartments. Thus, some mRNP proteins might possess initiation factor or protein synthetic activity if we accept Spirin's theory, i.e., "Eukaryotic messenger RNA and informosomes omnia mea mecum porto.
Collapse
|
18
|
Malik Z, Halbrecht I, Djaldetti M. Regulation of hemoglobin synthesis, iron metabolism, and maturation of Friend leukemic cells by 5-amino levulinic acid and hemin. Differentiation 1979; 13:71-9. [PMID: 288721 DOI: 10.1111/j.1432-0436.1979.tb01569.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
19
|
Bag J, Sells BH. The presence of protein kinase activity and acceptors of phosphate groups in nonpolysomal cytoplasmic messenger ribonucleoprotein complexes of embryonic chicken muscle. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(18)50730-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
20
|
Kramer G, Pinphanichakarn P, Hardesty B. Control of eukaryotic protein synthesis by phosphorylation. HAEMATOLOGY AND BLOOD TRANSFUSION 1979; 23:283-90. [PMID: 544364 DOI: 10.1007/978-3-642-67057-2_35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
21
|
Dabney B, Beaudet A. Stimulation of protein synthesis by hemin in extracts of Friend erythroleukemia cells. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34470-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
22
|
Granick J, Sassa S. Hemin control of heme biosynthesis in mouse Friend virus-transformed erythroleukemia cells in culture. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)30385-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
23
|
Henderson AB, Hardesty B. Evidence for an inhibitor of protein synthesis in rabbit reticulocytes activated by high pressure. Biochem Biophys Res Commun 1978; 83:715-23. [PMID: 697853 DOI: 10.1016/0006-291x(78)91048-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
24
|
Safer B, Anderson WF. The molecular mechanism of hemoglobin synthesis and its regulation in the reticulocyte. CRC CRITICAL REVIEWS IN BIOCHEMISTRY 1978; 5:261-90. [PMID: 363353 DOI: 10.3109/10409237809177144] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|