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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1996 May 28;93(11):5578–5583. doi: 10.1073/pnas.93.11.5578

Activation of the translational suppressor 4E-BP1 following infection with encephalomyocarditis virus and poliovirus.

A C Gingras 1, Y Svitkin 1, G J Belsham 1, A Pause 1, N Sonenberg 1
PMCID: PMC39289  PMID: 8643618

Abstract

Infection of cells with picornaviruses, such as poliovirus and encephalomyocarditis virus (EMCV), causes a shutoff of host protein synthesis. The molecular mechanism of the shutoff has been partly elucidated for poliovirus but not for EMCV. Translation initiation in eukaryotes is facilitated by the mRNA 5' cap structure to which the multisubunit translation initiation factor eIF4F binds to promote ribosome binding. Picornaviruses use a mechanism for the translation of their RNA that is independent of the cap structure. Poliovirus infection engenders the cleavage of the eIF4G (formerly p220) component of eIF4F and renders this complex inactive for cap-dependent translation. In contrast, EMCV infection does not result in eIF4G cleavage. Here, we report that both EMCV and poliovirus activate a translational repressor, 4E-BP1, that inhibits cap-dependent translation by binding to the cap-binding subunit eIF4E. Binding of eIF4E occurs only to the underphosphorylated form of 4E-BP1, and this interaction is highly regulated in cells. We show that 4E-BP1 becomes dephosphorylated upon infection with both EMCV and poliovirus. Dephosphorylation of 4E-BP1 temporally coincides with the shutoff of protein synthesis by EMCV but lags behind the shutoff and eIF4G cleavage in poliovirus-infected cells. Dephosphorylation of 4E-BP1 by specifically inhibiting cap-dependent translation may be the major cause of the shutoff phenomenon in EMCV-infected cells.

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Selected References

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  1. Abreu S. L., Lucas-Lenard J. Cellular protein synthesis shutoff by mengovirus: translation of nonviral and viral mRNA's in extracts from uninfected and infected Ehrlich ascites tumor cells. J Virol. 1976 Apr;18(1):182–194. doi: 10.1128/jvi.18.1.182-194.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bablanian R. Depression of macromolecular synthesis in cells infected with guanidine-dependent poliovirus under restrictive conditions. Virology. 1972 Jan;47(1):255–259. doi: 10.1016/0042-6822(72)90260-7. [DOI] [PubMed] [Google Scholar]
  3. Baglioni C., Simili M., Shafritz D. A. Initiation activity of EMC virus RNA, binding to initiation factor eIF-4B and shut-off of host cell protein synthesis. Nature. 1978 Sep 21;275(5677):240–243. doi: 10.1038/275240a0. [DOI] [PubMed] [Google Scholar]
  4. Beretta L., Gingras A. C., Svitkin Y. V., Hall M. N., Sonenberg N. Rapamycin blocks the phosphorylation of 4E-BP1 and inhibits cap-dependent initiation of translation. EMBO J. 1996 Feb 1;15(3):658–664. [PMC free article] [PubMed] [Google Scholar]
  5. Black T. L., Safer B., Hovanessian A., Katze M. G. The cellular 68,000-Mr protein kinase is highly autophosphorylated and activated yet significantly degraded during poliovirus infection: implications for translational regulation. J Virol. 1989 May;63(5):2244–2251. doi: 10.1128/jvi.63.5.2244-2251.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Blanar M. A., Rutter W. J. Interaction cloning: identification of a helix-loop-helix zipper protein that interacts with c-Fos. Science. 1992 May 15;256(5059):1014–1018. doi: 10.1126/science.1589769. [DOI] [PubMed] [Google Scholar]
  7. Bonneau A. M., Sonenberg N. Proteolysis of the p220 component of the cap-binding protein complex is not sufficient for complete inhibition of host cell protein synthesis after poliovirus infection. J Virol. 1987 Apr;61(4):986–991. doi: 10.1128/jvi.61.4.986-991.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Carrasco L. Picornavirus inhibitors. Pharmacol Ther. 1994;64(2):215–290. doi: 10.1016/0163-7258(94)90040-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Carrasco L., Smith A. E. Sodium ions and the shut-off of host cell protein synthesis by picornaviruses. Nature. 1976 Dec 23;264(5588):807–809. doi: 10.1038/264807a0. [DOI] [PubMed] [Google Scholar]
  10. Dalgarno L., Martin E. M., Liu S. L., Work T. S. Characterization of the products formed by the RNA polymerases of cells infected with encephalomyocarditis virus. J Mol Biol. 1966 Jan;15(1):77–91. doi: 10.1016/s0022-2836(66)80210-3. [DOI] [PubMed] [Google Scholar]
  11. Duke G. M., Hoffman M. A., Palmenberg A. C. Sequence and structural elements that contribute to efficient encephalomyocarditis virus RNA translation. J Virol. 1992 Mar;66(3):1602–1609. doi: 10.1128/jvi.66.3.1602-1609.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Duncan R., Milburn S. C., Hershey J. W. Regulated phosphorylation and low abundance of HeLa cell initiation factor eIF-4F suggest a role in translational control. Heat shock effects on eIF-4F. J Biol Chem. 1987 Jan 5;262(1):380–388. [PubMed] [Google Scholar]
  13. Edery I., Hümbelin M., Darveau A., Lee K. A., Milburn S., Hershey J. W., Trachsel H., Sonenberg N. Involvement of eukaryotic initiation factor 4A in the cap recognition process. J Biol Chem. 1983 Sep 25;258(18):11398–11403. [PubMed] [Google Scholar]
  14. Etchison D., Milburn S. C., Edery I., Sonenberg N., Hershey J. W. Inhibition of HeLa cell protein synthesis following poliovirus infection correlates with the proteolysis of a 220,000-dalton polypeptide associated with eucaryotic initiation factor 3 and a cap binding protein complex. J Biol Chem. 1982 Dec 25;257(24):14806–14810. [PubMed] [Google Scholar]
  15. Graves L. M., Bornfeldt K. E., Argast G. M., Krebs E. G., Kong X., Lin T. A., Lawrence J. C., Jr cAMP- and rapamycin-sensitive regulation of the association of eukaryotic initiation factor 4E and the translational regulator PHAS-I in aortic smooth muscle cells. Proc Natl Acad Sci U S A. 1995 Aug 1;92(16):7222–7226. doi: 10.1073/pnas.92.16.7222. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Haghighat A., Mader S., Pause A., Sonenberg N. Repression of cap-dependent translation by 4E-binding protein 1: competition with p220 for binding to eukaryotic initiation factor-4E. EMBO J. 1995 Nov 15;14(22):5701–5709. doi: 10.1002/j.1460-2075.1995.tb00257.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Helentjaris T., Ehrenfeld E. Control of protein synthesis in extracts from poliovirus-infected cells. I. mRNA discrimination by crude initiation factors. J Virol. 1978 May;26(2):510–521. doi: 10.1128/jvi.26.2.510-521.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Hiremath L. S., Webb N. R., Rhoads R. E. Immunological detection of the messenger RNA cap-binding protein. J Biol Chem. 1985 Jul 5;260(13):7843–7849. [PubMed] [Google Scholar]
  19. Hu C., Pang S., Kong X., Velleca M., Lawrence J. C., Jr Molecular cloning and tissue distribution of PHAS-I, an intracellular target for insulin and growth factors. Proc Natl Acad Sci U S A. 1994 Apr 26;91(9):3730–3734. doi: 10.1073/pnas.91.9.3730. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Jackson R. J., Howell M. T., Kaminski A. The novel mechanism of initiation of picornavirus RNA translation. Trends Biochem Sci. 1990 Dec;15(12):477–483. doi: 10.1016/0968-0004(90)90302-r. [DOI] [PubMed] [Google Scholar]
  21. Jang S. K., Kräusslich H. G., Nicklin M. J., Duke G. M., Palmenberg A. C., Wimmer E. A segment of the 5' nontranslated region of encephalomyocarditis virus RNA directs internal entry of ribosomes during in vitro translation. J Virol. 1988 Aug;62(8):2636–2643. doi: 10.1128/jvi.62.8.2636-2643.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Jen G., Thach R. E. Inhibition of host translation in encephalomyocarditis virus-infected L cells: a novel mechanism. J Virol. 1982 Jul;43(1):250–261. doi: 10.1128/jvi.43.1.250-261.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Kaufmann Y., Goldstein E., Penman S. Poliovirus-induced inhibition of polypeptide initiation in vitro on native polyribosomes. Proc Natl Acad Sci U S A. 1976 Jun;73(6):1834–1838. doi: 10.1073/pnas.73.6.1834. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  25. Lawrence C., Thach R. E. Encephalomyocarditis virus infection of mouse plasmacytoma cells. I. Inhibition of cellular protein synthesis. J Virol. 1974 Sep;14(3):598–610. doi: 10.1128/jvi.14.3.598-610.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Leibowitz R., Penman S. Regulation of protein synthesis in HeLa cells. 3. Inhibition during poliovirus infection. J Virol. 1971 Nov;8(5):661–668. doi: 10.1128/jvi.8.5.661-668.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Lin T. A., Kong X., Haystead T. A., Pause A., Belsham G., Sonenberg N., Lawrence J. C., Jr PHAS-I as a link between mitogen-activated protein kinase and translation initiation. Science. 1994 Oct 28;266(5185):653–656. doi: 10.1126/science.7939721. [DOI] [PubMed] [Google Scholar]
  28. Lin T. A., Kong X., Saltiel A. R., Blackshear P. J., Lawrence J. C., Jr Control of PHAS-I by insulin in 3T3-L1 adipocytes. Synthesis, degradation, and phosphorylation by a rapamycin-sensitive and mitogen-activated protein kinase-independent pathway. J Biol Chem. 1995 Aug 4;270(31):18531–18538. doi: 10.1074/jbc.270.31.18531. [DOI] [PubMed] [Google Scholar]
  29. Mader S., Lee H., Pause A., Sonenberg N. The translation initiation factor eIF-4E binds to a common motif shared by the translation factor eIF-4 gamma and the translational repressors 4E-binding proteins. Mol Cell Biol. 1995 Sep;15(9):4990–4997. doi: 10.1128/mcb.15.9.4990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Mosenkis J., Daniels-McQueen S., Janovec S., Duncan R., Hershey J. W., Grifo J. A., Merrick W. C., Thach R. E. Shutoff of host translation by encephalomyocarditis virus infection does not involve cleavage of the eucaryotic initiation factor 4F polypeptide that accompanies poliovirus infection. J Virol. 1985 May;54(2):643–645. doi: 10.1128/jvi.54.2.643-645.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. 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]
  32. Pause A., Méthot N., Svitkin Y., Merrick W. C., Sonenberg N. Dominant negative mutants of mammalian translation initiation factor eIF-4A define a critical role for eIF-4F in cap-dependent and cap-independent initiation of translation. EMBO J. 1994 Mar 1;13(5):1205–1215. doi: 10.1002/j.1460-2075.1994.tb06370.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Pelletier J., Sonenberg N. Internal initiation of translation of eukaryotic mRNA directed by a sequence derived from poliovirus RNA. Nature. 1988 Jul 28;334(6180):320–325. doi: 10.1038/334320a0. [DOI] [PubMed] [Google Scholar]
  34. Pérez L., Carrasco L. Lack of direct correlation between p220 cleavage and the shut-off of host translation after poliovirus infection. Virology. 1992 Jul;189(1):178–186. doi: 10.1016/0042-6822(92)90693-j. [DOI] [PubMed] [Google Scholar]
  35. 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]
  36. Rose J. K., Trachsel H., Leong K., Baltimore D. Inhibition of translation by poliovirus: inactivation of a specific initiation factor. Proc Natl Acad Sci U S A. 1978 Jun;75(6):2732–2736. doi: 10.1073/pnas.75.6.2732. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. 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]
  38. Rueckert R. R., Pallansch M. A. Preparation and characterization of encephalomyocarditis (EMC) virus. Methods Enzymol. 1981;78(Pt A):315–325. [PubMed] [Google Scholar]
  39. Scheper G. C., Voorma H. O., Thomas A. A. Eukaryotic initiation factors-4E and -4F stimulate 5' cap-dependent as well as internal initiation of protein synthesis. J Biol Chem. 1992 Apr 15;267(11):7269–7274. [PubMed] [Google Scholar]
  40. Shatkin A. J. Capping of eucaryotic mRNAs. Cell. 1976 Dec;9(4 Pt 2):645–653. doi: 10.1016/0092-8674(76)90128-8. [DOI] [PubMed] [Google Scholar]
  41. Sonenberg N. Regulation of translation by poliovirus. Adv Virus Res. 1987;33:175–204. doi: 10.1016/s0065-3527(08)60318-8. [DOI] [PubMed] [Google Scholar]
  42. Svitkin Y. V., Agol V. I. Complete translation of encephalomyocarditis virus RNA and faithful cleavage of virus-specific proteins in a cell-free system from Krebs-2 cells. FEBS Lett. 1978 Mar 1;87(1):7–11. doi: 10.1016/0014-5793(78)80121-5. [DOI] [PubMed] [Google Scholar]
  43. Svitkin Y. V., Ginevskaya V. A., Ugarova T. Y., Agol V. I. A cell-free model of the encephalomyocarditis virus-induced inhibition of host cell protein synthesis. Virology. 1978 Jun 1;87(1):199–203. doi: 10.1016/0042-6822(78)90172-1. [DOI] [PubMed] [Google Scholar]
  44. Svitkin Y. V., Lyapustin V. N., Lashkevich V. A., Agol V. I. Differences between translation products of tick-borne encephalitis virus RNA in cell-free systems from Krebs-2 cells and rabbit reticulocytes: involvement of membranes in the processing of nascent precursors of flavivirus structural proteins. Virology. 1984 Jun;135(2):536–541. doi: 10.1016/0042-6822(84)90207-1. [DOI] [PubMed] [Google Scholar]
  45. Svitkin Y. V., Ugarova T. Y., Ginevskaya V. A., Kalinina N. O., Scarlat I. V., Agol V. I. Efficiency of translation of viral and cellular mRNA's in extracts from cells infected with encephalomyocarditis virus. Intervirology. 1974;4(4):214–220. doi: 10.1159/000149965. [DOI] [PubMed] [Google Scholar]

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