Abstract
The structure of m7GpppN (where N is any nucleotide), termed cap, is present at the 5' end of all eukaryotic cellular mRNAs (except organellar). The eukaryotic initiation factor 4E (eIF-4E) binds to the cap and facilitates the formation of translation initiation complexes. eIF-4E is implicated in control of cell growth, as its overexpression causes malignant transformation of rodent cells and deregulates HeLa cell growth. It was suggested that overexpression of eIF-4E results in the enhanced translation of poorly translated mRNAs that encode growth-promoting proteins. Indeed, enhanced expression of several proteins, including cyclin D1 and ornithine decarboxylase (ODC), was documented in eIF-4E-overexpressing NTH 3T3 cells. However, the mechanism underlying this increase has not been elucidated. Here, we studied the mode by which eIF-4E increases the expression of cyclin D1 and ODC. We show that the increase in the amount of cyclin D1 and ODC is directly proportional to the degree of eIF-4E overexpression. Two mechanisms, which are not mutually exclusive, are responsible for the increase. In eIF-4E-overexpressing cells the rate of translation initiation of ODC mRNA was increased inasmuch as the mRNA sedimented with heavier polysomes. For cyclin D1 mRNA, translation initiation was not increased, but rather its amount in the cytoplasm increased, without a significant increase in total mRNA. Whereas, in the parental NIH 3T3 cell line, a large proportion of the cyclin D1 mRNA was confined to the nucleus, in eIF-4E-overexpressing cells the vast majority of the mRNA was present in the cytoplasm. These results indicate that eIF-4E affects directly or indirectly mRNA nucleocytoplasmic transport, in addition to its role in translation initiation.
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Auvinen M., Paasinen A., Andersson L. C., Hölttä E. Ornithine decarboxylase activity is critical for cell transformation. Nature. 1992 Nov 26;360(6402):355–358. doi: 10.1038/360355a0. [DOI] [PubMed] [Google Scholar]
- Belgrader P., Cheng J., Maquat L. E. Evidence to implicate translation by ribosomes in the mechanism by which nonsense codons reduce the nuclear level of human triosephosphate isomerase mRNA. Proc Natl Acad Sci U S A. 1993 Jan 15;90(2):482–486. doi: 10.1073/pnas.90.2.482. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Belgrader P., Cheng J., Zhou X., Stephenson L. S., Maquat L. E. Mammalian nonsense codons can be cis effectors of nuclear mRNA half-life. Mol Cell Biol. 1994 Dec;14(12):8219–8228. doi: 10.1128/mcb.14.12.8219. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Beltz G. A., Flint S. J. Inhibition of HeLa cell protein synthesis during adenovirus infection. Restriction of cellular messenger RNA sequences to the nucleus. J Mol Biol. 1979 Jun 25;131(2):353–373. doi: 10.1016/0022-2836(79)90081-0. [DOI] [PubMed] [Google Scholar]
- De Benedetti A., Rhoads R. E. Overexpression of eukaryotic protein synthesis initiation factor 4E in HeLa cells results in aberrant growth and morphology. Proc Natl Acad Sci U S A. 1990 Nov;87(21):8212–8216. doi: 10.1073/pnas.87.21.8212. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Feigenblum D., Schneider R. J. Modification of eukaryotic initiation factor 4F during infection by influenza virus. J Virol. 1993 Jun;67(6):3027–3035. doi: 10.1128/jvi.67.6.3027-3035.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Furuichi Y., LaFiandra A., Shatkin A. J. 5'-Terminal structure and mRNA stability. Nature. 1977 Mar 17;266(5599):235–239. doi: 10.1038/266235a0. [DOI] [PubMed] [Google Scholar]
- Grens A., Scheffler I. E. The 5'- and 3'-untranslated regions of ornithine decarboxylase mRNA affect the translational efficiency. J Biol Chem. 1990 Jul 15;265(20):11810–11816. [PubMed] [Google Scholar]
- Hamm J., Mattaj I. W. An abundant U6 snRNP found in germ cells and embryos of Xenopus laevis. EMBO J. 1989 Dec 20;8(13):4179–4187. doi: 10.1002/j.1460-2075.1989.tb08603.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hamm J., Mattaj I. W. Monomethylated cap structures facilitate RNA export from the nucleus. Cell. 1990 Oct 5;63(1):109–118. doi: 10.1016/0092-8674(90)90292-m. [DOI] [PubMed] [Google Scholar]
- Hershey J. W. Translational control in mammalian cells. Annu Rev Biochem. 1991;60:717–755. doi: 10.1146/annurev.bi.60.070191.003441. [DOI] [PubMed] [Google Scholar]
- Huang J. T., Schneider R. J. Adenovirus inhibition of cellular protein synthesis involves inactivation of cap-binding protein. Cell. 1991 Apr 19;65(2):271–280. doi: 10.1016/0092-8674(91)90161-q. [DOI] [PubMed] [Google Scholar]
- Izaurralde E., Lewis J., McGuigan C., Jankowska M., Darzynkiewicz E., Mattaj I. W. A nuclear cap binding protein complex involved in pre-mRNA splicing. Cell. 1994 Aug 26;78(4):657–668. doi: 10.1016/0092-8674(94)90530-4. [DOI] [PubMed] [Google Scholar]
- Izaurralde E., Stepinski J., Darzynkiewicz E., Mattaj I. W. A cap binding protein that may mediate nuclear export of RNA polymerase II-transcribed RNAs. J Cell Biol. 1992 Sep;118(6):1287–1295. doi: 10.1083/jcb.118.6.1287. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kaspar R. L., Gehrke L. Peripheral blood mononuclear cells stimulated with C5a or lipopolysaccharide to synthesize equivalent levels of IL-1 beta mRNA show unequal IL-1 beta protein accumulation but similar polyribosome profiles. J Immunol. 1994 Jul 1;153(1):277–286. [PubMed] [Google Scholar]
- Konarska M. M., Padgett R. A., Sharp P. A. Recognition of cap structure in splicing in vitro of mRNA precursors. Cell. 1984 Oct;38(3):731–736. doi: 10.1016/0092-8674(84)90268-x. [DOI] [PubMed] [Google Scholar]
- Koromilas A. E., Lazaris-Karatzas A., Sonenberg N. mRNAs containing extensive secondary structure in their 5' non-coding region translate efficiently in cells overexpressing initiation factor eIF-4E. EMBO J. 1992 Nov;11(11):4153–4158. doi: 10.1002/j.1460-2075.1992.tb05508.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lazaris-Karatzas A., Montine K. S., Sonenberg N. Malignant transformation by a eukaryotic initiation factor subunit that binds to mRNA 5' cap. Nature. 1990 Jun 7;345(6275):544–547. doi: 10.1038/345544a0. [DOI] [PubMed] [Google Scholar]
- Lazaris-Karatzas A., Sonenberg N. The mRNA 5' cap-binding protein, eIF-4E, cooperates with v-myc or E1A in the transformation of primary rodent fibroblasts. Mol Cell Biol. 1992 Mar;12(3):1234–1238. doi: 10.1128/mcb.12.3.1234. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lejbkowicz F., Goyer C., Darveau A., Neron S., Lemieux R., Sonenberg N. A fraction of the mRNA 5' cap-binding protein, eukaryotic initiation factor 4E, localizes to the nucleus. Proc Natl Acad Sci U S A. 1992 Oct 15;89(20):9612–9616. doi: 10.1073/pnas.89.20.9612. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Manzella J. M., Blackshear P. J. Regulation of rat ornithine decarboxylase mRNA translation by its 5'-untranslated region. J Biol Chem. 1990 Jul 15;265(20):11817–11822. [PubMed] [Google Scholar]
- Manzella J. M., Rychlik W., Rhoads R. E., Hershey J. W., Blackshear P. J. Insulin induction of ornithine decarboxylase. Importance of mRNA secondary structure and phosphorylation of eucaryotic initiation factors eIF-4B and eIF-4E. J Biol Chem. 1991 Feb 5;266(4):2383–2389. [PubMed] [Google Scholar]
- Maquat L. E. When cells stop making sense: effects of nonsense codons on RNA metabolism in vertebrate cells. RNA. 1995 Jul;1(5):453–465. [PMC free article] [PubMed] [Google Scholar]
- Minich W. B., Balasta M. L., Goss D. J., Rhoads R. E. Chromatographic resolution of in vivo phosphorylated and nonphosphorylated eukaryotic translation initiation factor eIF-4E: increased cap affinity of the phosphorylated form. Proc Natl Acad Sci U S A. 1994 Aug 2;91(16):7668–7672. doi: 10.1073/pnas.91.16.7668. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moore M., Schaack J., Baim S. B., Morimoto R. I., Shenk T. Induced heat shock mRNAs escape the nucleocytoplasmic transport block in adenovirus-infected HeLa cells. Mol Cell Biol. 1987 Dec;7(12):4505–4512. doi: 10.1128/mcb.7.12.4505. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Naeger L. K., Schoborg R. V., Zhao Q., Tullis G. E., Pintel D. J. Nonsense mutations inhibit splicing of MVM RNA in cis when they interrupt the reading frame of either exon of the final spliced product. Genes Dev. 1992 Jun;6(6):1107–1119. doi: 10.1101/gad.6.6.1107. [DOI] [PubMed] [Google Scholar]
- Ohno M., Kataoka N., Shimura Y. A nuclear cap binding protein from HeLa cells. Nucleic Acids Res. 1990 Dec 11;18(23):6989–6995. doi: 10.1093/nar/18.23.6989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Okamoto A., Jiang W., Kim S. J., Spillare E. A., Stoner G. D., Weinstein I. B., Harris C. C. Overexpression of human cyclin D1 reduces the transforming growth factor beta (TGF-beta) type II receptor and growth inhibition by TGF-beta 1 in an immortalized human esophageal epithelial cell line. Proc Natl Acad Sci U S A. 1994 Nov 22;91(24):11576–11580. doi: 10.1073/pnas.91.24.11576. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Patzelt E., Blaas D., Kuechler E. CAP binding proteins associated with the nucleus. Nucleic Acids Res. 1983 Sep 10;11(17):5821–5835. doi: 10.1093/nar/11.17.5821. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pause A., Belsham G. J., Gingras A. C., Donzé O., Lin T. A., Lawrence J. C., Jr, Sonenberg N. Insulin-dependent stimulation of protein synthesis by phosphorylation of a regulator of 5'-cap function. Nature. 1994 Oct 27;371(6500):762–767. doi: 10.1038/371762a0. [DOI] [PubMed] [Google Scholar]
- Pelletier J., Sonenberg N. Insertion mutagenesis to increase secondary structure within the 5' noncoding region of a eukaryotic mRNA reduces translational efficiency. Cell. 1985 Mar;40(3):515–526. doi: 10.1016/0092-8674(85)90200-4. [DOI] [PubMed] [Google Scholar]
- Qian L., Theodor L., Carter M., Vu M. N., Sasaki A. W., Wilkinson M. F. T cell receptor-beta mRNA splicing: regulation of unusual splicing intermediates. Mol Cell Biol. 1993 Mar;13(3):1686–1696. doi: 10.1128/mcb.13.3.1686. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ray B. K., Lawson T. G., Kramer J. C., Cladaras M. H., Grifo J. A., Abramson R. D., Merrick W. C., Thach R. E. ATP-dependent unwinding of messenger RNA structure by eukaryotic initiation factors. J Biol Chem. 1985 Jun 25;260(12):7651–7658. [PubMed] [Google Scholar]
- Rhoads R. E., Joshi-Barve S., Rinker-Schaeffer C. Mechanism of action and regulation of protein synthesis initiation factor 4E: effects on mRNA discrimination, cellular growth rate, and oncogenesis. Prog Nucleic Acid Res Mol Biol. 1993;46:183–219. doi: 10.1016/s0079-6603(08)61022-3. [DOI] [PubMed] [Google Scholar]
- Rinker-Schaeffer C. W., Graff J. R., De Benedetti A., Zimmer S. G., Rhoads R. E. Decreasing the level of translation initiation factor 4E with antisense RNA causes reversal of ras-mediated transformation and tumorigenesis of cloned rat embryo fibroblasts. Int J Cancer. 1993 Nov 11;55(5):841–847. doi: 10.1002/ijc.2910550525. [DOI] [PubMed] [Google Scholar]
- Rosenwald I. B., Lazaris-Karatzas A., Sonenberg N., Schmidt E. V. Elevated levels of cyclin D1 protein in response to increased expression of eukaryotic initiation factor 4E. Mol Cell Biol. 1993 Dec;13(12):7358–7363. doi: 10.1128/mcb.13.12.7358. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rozen F., Edery I., Meerovitch K., Dever T. E., Merrick W. C., Sonenberg N. Bidirectional RNA helicase activity of eucaryotic translation initiation factors 4A and 4F. Mol Cell Biol. 1990 Mar;10(3):1134–1144. doi: 10.1128/mcb.10.3.1134. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rozen F., Sonenberg N. Identification of nuclear cap specific proteins in HeLa cells. Nucleic Acids Res. 1987 Aug 25;15(16):6489–6500. doi: 10.1093/nar/15.16.6489. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shantz L. M., Pegg A. E. Overproduction of ornithine decarboxylase caused by relief of translational repression is associated with neoplastic transformation. Cancer Res. 1994 May 1;54(9):2313–2316. [PubMed] [Google Scholar]
- Shatkin A. J. mRNA cap binding proteins: essential factors for initiating translation. Cell. 1985 Feb;40(2):223–224. doi: 10.1016/0092-8674(85)90132-1. [DOI] [PubMed] [Google Scholar]
- Smith M. R., Jaramillo M., Liu Y. L., Dever T. E., Merrick W. C., Kung H. F., Sonenberg N. Translation initiation factors induce DNA synthesis and transform NIH 3T3 cells. New Biol. 1990 Jul;2(7):648–654. [PubMed] [Google Scholar]
- Sonenberg N. Remarks on the mechanism of ribosome binding to eukaryotic mRNAs. Gene Expr. 1993;3(3):317–323. [PMC free article] [PubMed] [Google Scholar]
- Sonenberg N. Translation factors as effectors of cell growth and tumorigenesis. Curr Opin Cell Biol. 1993 Dec;5(6):955–960. doi: 10.1016/0955-0674(93)90076-3. [DOI] [PubMed] [Google Scholar]
- Thach R. E. Cap recap: the involvement of eIF-4F in regulating gene expression. Cell. 1992 Jan 24;68(2):177–180. doi: 10.1016/0092-8674(92)90461-k. [DOI] [PubMed] [Google Scholar]
- Urlaub G., Mitchell P. J., Ciudad C. J., Chasin L. A. Nonsense mutations in the dihydrofolate reductase gene affect RNA processing. Mol Cell Biol. 1989 Jul;9(7):2868–2880. doi: 10.1128/mcb.9.7.2868. [DOI] [PMC free article] [PubMed] [Google Scholar]