Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

A mechanistic overview of translation initiation in eukaryotes

Nature Structural & Molecular Biology volume 19, pages 568–576 (2012)Cite this article

Subjects

Abstract

Translation initiation in eukaryotes is a complex and highly regulated process requiring the action of at least 12 protein factors. The pathway is distinguished by the formation of a pre-initiation complex that recruits the 5′ end of the mRNA and scans along it to locate the start codon. During the past decade, a combination of genetics, biochemistry and structural studies has begun to illuminate key molecular events in this critical phase of gene expression. Here, we outline our current understanding of eukaryotic translation initiation and discuss important outstanding challenges.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Schematic of the translation initiation pathway in eukaryotes.
Figure 2: The architecture of the open PIC.
Figure 3: Two models for mRNA recruitment.
Figure 4: Scanning, two ways.
Figure 5: A model for start codon recognition and subunit joining.

Similar content being viewed by others

Accession codes

Accessions

Protein Data Bank

References

  1. Sonenberg, N. & Hinnebusch, A.G. Regulation of translation initiation in eukaryotes: mechanisms and biological targets. Cell 136, 731–745 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Jackson, R.J., Hellen, C.U.T. & Pestova, T.V. The mechanism of eukaryotic translation initiation and principles of its regulation. Nat. Rev. Mol. Cell Biol. 11, 113–127 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Hinnebusch, A.G. Molecular mechanism of scanning and start codon selection in eukaryotes. Microbiol. Mol. Biol. Rev. 75, 434–467 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Kolitz, S.E. & Lorsch, J.R. Eukaryotic initiator tRNA: finely tuned and ready for action. FEBS Lett. 584, 396–404 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Kapp, L.D. & Lorsch, J. GTP-dependent recognition of the methionine moiety on initiator tRNA by translation factor eIF2. J. Mol. Biol. 335, 923–936 (2004).

    Article  CAS  PubMed  Google Scholar 

  6. Naveau, M., Lazennec-Schurdevin, C., Panvert, M., Mechulam, Y. & Schmitt, E. tRNA binding properties of eukaryotic translation initiation factor 2 from Encephalitozoon cuniculi. Biochemistry 49, 8680–8688 (2010).

    Article  CAS  PubMed  Google Scholar 

  7. Shin, B.-S. et al. Initiation factor eIF2γ promotes eIF2–GTP–Met-tRNAiMet ternary complex binding to the 40S ribosome. Nat. Struct. Mol. Biol. 18, 1227–1234 (2011). Provides the first structural information on the position and architecture of the ternary complex on the 40S subunit.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Asano, K., Clayton, J., Shalev, A. & Hinnebusch, A.G. A multifactor complex of eukaryotic initiation factors, eIF1, eIF2, eIF3, eIF5, and initiator tRNAMet is an important translation initiation intermediate in vivo. Genes Dev. 14, 2534–2546 (2000).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Singh, C.R., He, H., Ii, M., Yamamoto, Y. & Asano, K. Efficient incorporation of eukaryotic initiation factor 1 into the multifactor complex is critical for formation of functional ribosomal preinitiation complexes in vivo. J. Biol. Chem. 279, 31910–31920 (2004).

    Article  CAS  PubMed  Google Scholar 

  10. Olsen, D.S. et al. Domains of eIF1A that mediate binding to eIF2, eIF3 and eIF5B and promote ternary complex recruitment in vivo. EMBO J. 22, 193–204 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Pisarev, A.V. et al. Specific functional interactions of nucleotides at key −3 and +4 positions flanking the initiation codon with components of the mammalian 48S translation initiation complex. Genes Dev. 20, 624–636 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Asano, K. et al. Multiple roles for the C-terminal domain of eIF5 in translation initiation complex assembly and GTPase activation. EMBO J. 20, 2326–2337 (2001).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  13. Algire, M.A. et al. Development and characterization of a reconstituted yeast translation initiation system. RNA 8, 382–397 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Majumdar, R., Bandyopadhyay, A. & Maitra, U. Mammalian translation initiation factor eIF1 functions with eIF1A and eIF3 in the formation of a stable 40 40 S preinitiation complex. J. Biol. Chem. 278, 6580–6587 (2003).

    Article  CAS  PubMed  Google Scholar 

  15. Kolupaeva, V.G., Unbehaun, A., Lomakin, I.B., Hellen, C.U.T. & Pestova, T.V. Binding of eukaryotic initiation factor 3 to ribosomal 40S subunits and its role in ribosomal dissociation and anti-association. RNA 11, 470–486 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Lomakin, I.B. Position of eukaryotic initiation factor eIF1 on the 40S ribosomal subunit determined by directed hydroxyl radical probing. Genes Dev. 17, 2786–2797 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Rabl, J., Leibundgut, M., Ataide, S.F., Haag, A. & Ban, N. Crystal structure of the eukaryotic 40S ribosomal subunit in complex with initiation factor 1. Science 331, 730–736 (2011). Crystal structure of the Tetrahymena 40S subunit bound to eIF1, suggesting a mechanism for eIF1 release upon full accommodation of the initiator tRNA into the P site.

    Article  CAS  PubMed  Google Scholar 

  18. Yu, Y. et al. Position of eukaryotic translation initiation factor eIF1A on the 40S ribosomal subunit mapped by directed hydroxyl radical probing. Nucleic Acids Res. 37, 5167–5182 (2009). Maps the positions of the eIF1A domains on the 40S subunit.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Alone, P.V. & Dever, T.E. Direct binding of translation initiation factor eIF2γ-G domain to its GTPase-activating and GDP-GTP exchange factors eIF5 and eIF2Bɛ. J. Biol. Chem. 281, 12636–12644 (2006).

    Article  CAS  PubMed  Google Scholar 

  20. Paulin, F.E., Campbell, L.E., O'Brien, K., Loughlin, J. & Proud, C.G. Eukaryotic translation initiation factor 5 (eIF5) acts as a classical GTPase-activator protein. Curr. Biol. 11, 55–59 (2001).

    Article  CAS  PubMed  Google Scholar 

  21. Das, S., Ghosh, R. & Maitra, U. Eukaryotic translation initiation factor 5 functions as a GTPase-activating protein. J. Biol. Chem. 276, 6720–6726 (2001).

    Article  CAS  PubMed  Google Scholar 

  22. Asano, K., Krishnamoorthy, T., Phan, L., Pavitt, G.D. & Hinnebusch, A.G. Conserved bipartite motifs in yeast eIF5 and eIF2Bɛ, GTPase-activating and GDP-GTP exchange factors in translation initiation, mediate binding to their common substrate eIF2. EMBO J. 18, 1673–1688 (1999).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Yamamoto, Y. et al. The eukaryotic initiation factor (eIF) 5 HEAT domain mediates multifactor assembly and scanning with distinct interfaces to eIF1, eIF2, eIF3, and eIF4G. Proc. Natl. Acad. Sci. USA 102, 16164–16169 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Siridechadilok, B., Fraser, C., Hall, R. & Doudna, J. Structural roles for human translation factor eIF3 in initiation of protein synthesis. Science 310, 1513–1515 (2005).

    Article  CAS  PubMed  Google Scholar 

  25. Pisarev, A.V., Kolupaeva, V.G., Yusupov, M.M., Hellen, C.U.T. & Pestova, T.V. Ribosomal position and contacts of mRNA in eukaryotic translation initiation complexes. EMBO J. 27, 1609–1621 (2008). Provides structural information on the relative positions of eIF3 and mRNA on the 40S subunit.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Valášek, L. et al. The yeast eIF3 subunits TIF32/a, NIP1/c, and eIF5 make critical connections with the 40S ribosome in vivo. Genes Dev. 17, 786–799 (2003).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  27. Chiu, W.-L. et al. The C-terminal region of eukaryotic translation initiation factor 3a (eIF3a) promotes mRNA recruitment, scanning, and, together with eIF3j and the eIF3b RNA recognition motif, selection of AUG start codons. Mol. Cell. Biol. 30, 4415–4434 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Sokabe, M., Fraser, C.S. & Hershey, J.W.B. The human translation initiation multi-factor complex promotes methionyl-tRNAi binding to the 40S ribosomal subunit. Nucleic Acids Res. 40, 905–913 (2012).

    Article  CAS  PubMed  Google Scholar 

  29. Valášek, L., Nielsen, K.H. & Hinnebusch, A.G. Direct eIF2-eIF3 contact in the multifactor complex is important for translation initiation in vivo. EMBO J. 21, 5886–5898 (2002).

    Article  PubMed  PubMed Central  Google Scholar 

  30. Nielsen, K.H. et al. Functions of eIF3 downstream of 48S assembly impact AUG recognition and GCN4 translational control. EMBO J. 23, 1166–1177 (2004).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Valášek, L., Nielsen, K.H., Zhang, F., Fekete, C.A. & Hinnebusch, A.G. Interactions of eukaryotic translation initiation factor 3 (eIF3) subunit NIP1/c with eIF1 and eIF5 promote preinitiation complex assembly and regulate start codon selection. Mol. Cell. Biol. 24, 9437–9455 (2004).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  32. Singh, C.R. et al. Eukaryotic translation initiation factor 5 is critical for integrity of the scanning preinitiation complex and accurate control of GCN4 translation. Mol. Cell. Biol. 25, 5480–5491 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Jivotovskaya, A.V., Valášek, L., Hinnebusch, A.G. & Nielsen, K.H. Eukaryotic translation initiation factor 3 (eIF3) and eIF2 can promote mRNA binding to 40S subunits independently of eIF4G in yeast. Mol. Cell. Biol. 26, 1355–1372 (2006). Provides evidence for the central role of eIF3 in mRNA recruitment in vivo.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Hasek, J. et al. Rpg1p, the subunit of the Saccharomyces cerevisiae eIF3 core complex, is a microtubule-interacting protein. Cell Motil. Cytoskeleton 45, 235–246 (2000).

    Article  CAS  PubMed  Google Scholar 

  35. Palecek, J., Hasek, J. & Ruis, H. Rpg1p/Tif32p, a subunit of translation initiation factor 3, interacts with actin-associated protein Sla2p. Biochem. Biophys. Res. Commun. 282, 1244–1250 (2001).

    Article  CAS  PubMed  Google Scholar 

  36. Pincheira, R., Chen, Q., Huang, Z. & Zhang, J.T. Two subcellular localizations of eIF3 p170 and its interaction with membrane-bound microfilaments: implications for alternative functions of p170. Eur. J. Cell Biol. 80, 410–418 (2001).

    Article  CAS  PubMed  Google Scholar 

  37. Maag, D. Communication between eukaryotic translation initiation factors 1 and 1A on the yeast small ribosomal subunit. J. Mol. Biol. 330, 917–924 (2003).

    Article  CAS  PubMed  Google Scholar 

  38. Pestova, T.V., Borukhov, S.I. & Hellen, C.U.T. Eukaryotic ribosomes require initiation factors 1 and 1A to locate initiation codons. Nature 394, 854–859 (1998).

    Article  CAS  PubMed  Google Scholar 

  39. Passmore, L.A. et al. The eukaryotic translation initiation factors eIF1 and eIF1A induce an open conformation of the 40S ribosome. Mol. Cell 26, 41–50 (2007). Cryo-EM reconstructions highlighting the role of eIF1 in stabilizing the open state of the 40S subunit.

    Article  CAS  PubMed  Google Scholar 

  40. Maag, D., Fekete, C., Gryczynski, Z. & Lorsch, J. A conformational change in the eukaryotic translation preinitiation complex and release of eIF1 signal recognition of the start codon. Mol. Cell 17, 265–275 (2005).Demonstrates that eIF1 is released from the PIC upon start codon recognition.

    Article  CAS  PubMed  Google Scholar 

  41. Saini, A.K., Nanda, J.S., Lorsch, J.R. & Hinnebusch, A.G. Regulatory elements in eIF1A control the fidelity of start codon selection by modulating tRNAiMet binding to the ribosome. Genes Dev. 24, 97–110 (2010). Maps the regions of the eIF1A CTT and NTT responsible for their opposing roles in start codon recognition.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  42. Fekete, C.A. et al. N- and C-terminal residues of eIF1A have opposing effects on the fidelity of start codon selection. EMBO J. 26, 1602–1614 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Chaudhuri, J., Chowdhury, D. & Maitra, U. Distinct functions of eukaryotic translation initiation factors eIF1A and eIF3 in the formation of the 40 S ribosomal preinitiation complex. J. Biol. Chem. 274, 17975–17980 (1999).

    Article  CAS  PubMed  Google Scholar 

  44. Uchida, N., Hoshino, S.-I., Imataka, H., Sonenberg, N. & Katada, T. A novel role of the mammalian GSPT/eRF3 associating with poly(A)-binding protein in Cap/Poly(A)-dependent translation. J. Biol. Chem. 277, 50286–50292 (2002).

    Article  CAS  PubMed  Google Scholar 

  45. Park, E.-H. et al. Multiple elements in the eIF4G1 N-terminus promote assembly of eIF4G1•PABP mRNPs in vivo. EMBO J. 30, 302–316 (2011).

    Article  CAS  PubMed  Google Scholar 

  46. Kaye, N.M., Emmett, K.J., Merrick, W.C. & Jankowsky, E. Intrinsic RNA binding by the eukaryotic initiation factor 4F depends on a minimal RNA length but not on the m7G cap. J. Biol. Chem. 284, 17742–17750 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Mitchell, S.F. et al. The 5′-7-methylguanosine cap on eukaryotic mRNAs serves both to stimulate canonical translation initiation and to block an alternative pathway. Mol. Cell 39, 950–962 (2010). Demonstrates that eIF3 is critical for mRNA recruitment in vitro and identifies a new role for the 5′ cap in blocking the formation of aberrant 43S–mRNA complexes.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Yanagiya, A. et al. Requirement of RNA binding of mammalian eukaryotic translation initiation factor 4GI (eIF4GI) for efficient interaction of eIF4E with the mRNA cap. Mol. Cell. Biol. 29, 1661–1669 (2009).

    Article  CAS  PubMed  Google Scholar 

  49. Tarun, S.Z., Wells, S., Deardorff, J. & Sachs, A. Translation initiation factor eIF4G mediates in vitro poly(A) tail-dependent translation. Proc. Natl. Acad. Sci. USA 94, 9046–9051 (1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  50. Kahvejian, A., Svitkin, Y.V., Sukarieh, R., M'Boutchou, M.-N. & Sonenberg, N. Mammalian poly(A)-binding protein is a eukaryotic translation initiation factor, which acts via multiple mechanisms. Genes Dev. 19, 104–113 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  51. Hinton, T.M., Coldwell, M.J., Carpenter, G.A., Morley, S.J. & Pain, V.M. Functional analysis of individual binding activities of the scaffold protein eIF4G. J. Biol. Chem. 282, 1695–1708 (2007).

    Article  CAS  PubMed  Google Scholar 

  52. Svitkin, Y.V. et al. General RNA-binding proteins have a function in poly(A)-binding protein-dependent translation. EMBO J. 28, 58–68 (2009). Provides evidence that the effects of PABP and the poly(A) tail are most pronounced under conditions of strong competition for mRNA binding.

    Article  CAS  PubMed  Google Scholar 

  53. Ramírez-Valle, F., Braunstein, S., Zavadil, J., Formenti, S.C. & Schneider, R.J. eIF4GI links nutrient sensing by mTOR to cell proliferation and inhibition of autophagy. J. Cell Biol. 181, 293–307 (2008).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  54. Park, E.-H., Zhang, F., Warringer, J., Sunnerhagen, P. & Hinnebusch, A.G. Depletion of eIF4G from yeast cells narrows the range of translational efficiencies genome-wide. BMC Genomics 12, 68 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  55. Mayberry, L.K., Allen, M.L., Dennis, M.D. & Browning, K.S. Evidence for variation in the optimal translation initiation complex: plant eIF4B, eIF4F, and eIF(iso)4F differentially promote translation of mRNAs. Plant Physiol. 150, 1844–1854 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  56. Lorsch, J.R. & Herschlag, D. The DEAD box protein eIF4A. 1. A minimal kinetic and thermodynamic framework reveals coupled binding of RNA and nucleotide. Biochemistry 37, 2180–2193 (1998).

    Article  CAS  PubMed  Google Scholar 

  57. Sengoku, T., Nureki, O., Nakamura, A., Kobayashi, S. & Yokoyama, S. Structural basis for RNA unwinding by the DEAD-box protein Drosophila Vasa. Cell 125, 287–300 (2006).

    Article  CAS  PubMed  Google Scholar 

  58. Liu, F., Putnam, A. & Jankowsky, E. ATP hydrolysis is required for DEAD-box protein recycling but not for duplex unwinding. Proc. Natl. Acad. Sci. USA 105, 20209–20214 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Oberer, M., Marintchev, A. & Wagner, G. Structural basis for the enhancement of eIF4A helicase activity by eIF4G. Genes Dev. 19, 2212–2223 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  60. Marintchev, A. et al. Topology and regulation of the human eIF4A/4G/4H helicase complex in translation initiation. Cell 136, 447–460 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  61. Hilbert, M., Kebbel, F., Gubaev, A. & Klostermeier, D. eIF4G stimulates the activity of the DEAD box protein eIF4A by a conformational guidance mechanism. Nucleic Acids Res. 39, 2260–2270 (2011).

    Article  CAS  PubMed  Google Scholar 

  62. Rogers, G.W., Richter, N.J., Lima, W.F. & Merrick, W.C. Modulation of the helicase activity of eIF4A by eIF4B, eIF4H, and eIF4F. J. Biol. Chem. 276, 30914–30922 (2001).

    Article  CAS  PubMed  Google Scholar 

  63. Rozovsky, N., Butterworth, A.C. & Moore, M.J. Interactions between eIF4AI and its accessory factors eIF4B and eIF4H. RNA 14, 2136–2148 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  64. Bi, X., Ren, J. & Goss, D.J. Wheat germ translation initiation factor eIF4B affects eIF4A and eIFiso4F helicase activity by increasing the ATP binding affinity of eIF4A. Biochemistry 39, 5758–5765 (2000).

    Article  CAS  PubMed  Google Scholar 

  65. Cheng, S., Sultana, S., Goss, D.J. & Gallie, D.R. Translation initiation factor 4B homodimerization, RNA binding, and interaction with Poly(A)-binding protein are enhanced by zinc. J. Biol. Chem. 283, 36140–36153 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  66. Özeş, A.R., Feoktistova, K., Avanzino, B.C. & Fraser, C.S. Duplex unwinding and ATPase activities of the DEAD-box helicase eIF4A are coupled by eIF4G and eIF4B. J. Mol. Biol. 412, 674–687 (2011).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  67. Nielsen, K.H. et al. Synergistic activation of eIF4A by eIF4B and eIF4G. Nucleic Acids Res. 39, 2678–2689 (2011).

    Article  CAS  PubMed  Google Scholar 

  68. Altmann, M., Wittmer, B., Methot, N., Sonenberg, N. & Trachsel, H. The Saccharomyces cerevisiae translation initiation factor Tif3 and its mammalian homologue, eIF-4B, have RNA annealing activity. EMBO J. 14, 3820–3827 (1995).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  69. Niederberger, N., Trachsel, H. & Altmann, M. The RNA recognition motif of yeast translation initiation factor Tif3/eIF4B is required but not sufficient for RNA strand-exchange and translational activity. RNA 4, 1259–1267 (1998).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  70. LeFebvre, A.K. et al. Translation initiation factor eIF4G–1 binds to eIF3 through the eIF3e subunit. J. Biol. Chem. 281, 22917–22932 (2006).

    Article  CAS  PubMed  Google Scholar 

  71. Méthot, N., Song, M.S. & Sonenberg, N. A region rich in aspartic acid, arginine, tyrosine, and glycine (DRYG) mediates eukaryotic initiation factor 4B (eIF4B) self-association and interaction with eIF3. Mol. Cell. Biol. 16, 5328–5334 (1996).

    Article  PubMed  PubMed Central  Google Scholar 

  72. Dmitriev, S.E., Terenin, I., Dunaevsky, Y., Merrick, W. & Shatsky, I. Assembly of 48S translation initiation complexes from purified components with mRNAs that have some base pairing within their 5′ untranslated regions. Mol. Cell. Biol. 23, 8925–8933 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  73. Hinnebusch, A.G. eIF3: a versatile scaffold for translation initiation complexes. Trends Biochem. Sci. 31, 553–562 (2006).

    Article  CAS  PubMed  Google Scholar 

  74. Nielsen, K.H., Valasek, L., Sykes, C., Jivotovskaya, A. & Hinnebusch, A.G. Interaction of the RNP1 motif in PRT1 with HCR1 promotes 40S binding of eukaryotic initiation factor 3 in yeast. Mol. Cell. Biol. 26, 2984–2998 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  75. Unbehaun, A., Borukhov, S.I., Hellen, C.U.T. & Pestova, T.V. Release of initiation factors from 48S complexes during ribosomal subunit joining and the link between establishment of codon-anticodon base-pairing and hydrolysis of eIF2-bound GTP. Genes Dev. 18, 3078–3093 (2004).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  76. Cuchalová, L. et al. The RNA recognition motif of eukaryotic translation initiation factor 3g (eIF3g) is required for resumption of scanning of posttermination ribosomes for reinitiation on GCN4 and together with eIF3i stimulates linear scanning. Mol. Cell. Biol. 30, 4671–4686 (2010).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  77. Elantak, L. et al. The indispensable N-terminal half of eIF3j/HCR1 cooperates with its structurally conserved binding partner eIF3b/PRT1-RRM and with eIF1A in stringent AUG selection. J. Mol. Biol. 396, 1097–1116 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  78. Mignone, F., Gissi, C., Liuni, S. & Pesole, G. Untranslated regions of mRNAs. Genome Biol. 3, reviews0004.1–reviews0004.10 (2002).

  79. Ivanov, I.P., Loughran, G., Sachs, M.S. & Atkins, J.F. Initiation context modulates autoregulation of eukaryotic translation initiation factor 1 (eIF1). Proc. Natl. Acad. Sci. USA 107, 18056–18060 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  80. Martin-Marcos, P., Cheung, Y.-N. & Hinnebusch, A.G. Functional elements in initiation factors 1, 1A, and 2β discriminate against poor AUG context and non-AUG start codons. Mol. Cell. Biol. 31, 4814–4831 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  81. Berthelot, K., Muldoon, M., Rajkowitsch, L., Hughes, J. & McCarthy, J.E.G. Dynamics and processivity of 40S ribosome scanning on mRNA in yeast. Mol. Microbiol. 51, 987–1001 (2004).

    Article  CAS  PubMed  Google Scholar 

  82. Vassilenko, K.S., Alekhina, O.M., Dmitriev, S.E., Shatsky, I.N. & Spirin, A.S. Unidirectional constant rate motion of the ribosomal scanning particle during eukaryotic translation initiation. Nucleic Acids Res. 39, 5555–5567 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  83. Pestova, T.V. & Kolupaeva, V. The roles of individual eukaryotic translation initiation factors in ribosomal scanning and initiation codon selection. Genes Dev. 16, 2906–2922 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  84. Prévôt, D. et al. Characterization of a novel RNA-binding region of eIF4GI critical for ribosomal scanning. EMBO J. 22, 1909–1921 (2003).

    Article  PubMed  PubMed Central  Google Scholar 

  85. Watanabe, R. et al. The eukaryotic initiation factor (eIF) 4G HEAT domain promotes translation re-initiation in yeast both dependent on and independent of eIF4A mRNA helicase. J. Biol. Chem. 285, 21922–21933 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  86. Lindqvist, L., Imataka, H. & Pelletier, J. Cap-dependent eukaryotic initiation factor-mRNA interactions probed by cross-linking. RNA 14, 960–969 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  87. von der Haar, T. & McCarthy, J.E. Intracellular translation initiation factor levels in Saccharomyces cerevisiae and their role in cap-complex function. Mol. Microbiol. 46, 531–544 (2002).

    Article  CAS  PubMed  Google Scholar 

  88. Pisareva, V.P., Pisarev, A.V., Komar, A.A., Hellen, C.U.T. & Pestova, T.V. Translation initiation on mammalian mRNAs with structured 5′UTRs requires DExH-box protein DHX29. Cell 135, 1237–1250 (2008). Demonstrates that helicases besides eIF4A are required for recruitment and scanning of mRNAs containing highly stable, secondary structure elements.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  89. Abaeva, I.S., Marintchev, A., Pisareva, V.P., Hellen, C.U.T. & Pestova, T.V. Bypassing of stems versus linear base-by-base inspection of mammalian mRNAs during ribosomal scanning. EMBO J. 30, 115–129 (2011).

    Article  CAS  PubMed  Google Scholar 

  90. Spirin, A.S. How does a scanning ribosomal particle move along the 5′-untranslated region of eukaryotic mRNA? Brownian Ratchet model. Biochemistry 48, 10688–10692 (2009).

    Article  CAS  PubMed  Google Scholar 

  91. Rajagopal, V., Park, E.-H., Hinnebusch, A.G. & Lorsch, J.R. Specific domains in yeast eIF4G strongly bias the RNA unwinding activity of the eIF4F complex towards duplexes with 5′-overhangs. J. Biol. Chem. published online, doi:10.1074/jbc.M112.347278 (30 March 2012).

  92. Algire, M.A., Maag, D. & Lorsch, J.R. Pi release from eIF2, not GTP hydrolysis, is the step controlled by start-site selection during eukaryotic translation initiation. Mol. Cell 20, 251–262 (2005).

    Article  CAS  PubMed  Google Scholar 

  93. Cheung, Y.-N. et al. Dissociation of eIF1 from the 40S ribosomal subunit is a key step in start codon selection in vivo. Genes Dev. 21, 1217–1230 (2007). Demonstrates the key role of eIF1 in maintaining start codon fidelity in vivo.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  94. Nanda, J.S. et al. eIF1 controls multiple steps in start codon recognition during eukaryotic translation initiation. J. Mol. Biol. 394, 268–285 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  95. Reibarkh, M. et al. Eukaryotic initiation factor (eIF) 1 carries two distinct eIF5-binding faces important for multifactor assembly and AUG selection. J. Biol. Chem. 283, 1094–1103 (2008).

    Article  CAS  PubMed  Google Scholar 

  96. Loughran, G., Sachs, M.S., Atkins, J.F. & Ivanov, I.P. Stringency of start codon selection modulates autoregulation of translation initiation factor eIF5. Nucleic Acids Res. 40, 2898–2906 (2012).

    Article  CAS  PubMed  Google Scholar 

  97. Maag, D., Algire, M.A. & Lorsch, J.R. Communication between eukaryotic translation initiation factors 5 and 1A within the ribosomal pre-initiation complex plays a role in start site selection. J. Mol. Biol. 356, 724–737 (2006).

    Article  CAS  PubMed  Google Scholar 

  98. Herrmannová, A. et al. Structural analysis of an eIF3 subcomplex reveals conserved interactions required for a stable and proper translation pre-initiation complex assembly. Nucleic Acids Res. 40, 2294–2311 (2012).

    Article  PubMed  CAS  Google Scholar 

  99. Pestova, T.V. et al. The joining of ribosomal subunits in eukaryotes requires eIF5B. Nature 403, 332–335 (2000).

    Article  CAS  PubMed  Google Scholar 

  100. Acker, M.G., Shin, B.-S., Dever, T.E. & Lorsch, J.R. Interaction between eukaryotic initiation factors 1A and 5B is required for efficient ribosomal subunit joining. J. Biol. Chem. 281, 8469–8475 (2006).

    Article  CAS  PubMed  Google Scholar 

  101. Acker, M.G. et al. Kinetic analysis of late steps of eukaryotic translation initiation. J. Mol. Biol. 385, 491–506 (2009).

    Article  CAS  PubMed  Google Scholar 

  102. Shin, B.S. et al. Uncoupling of initiation factor eIF5B/IF2 GTPase and translational activities by mutations that lower ribosome affinity. Cell 111, 1015–1025 (2002).

    Article  CAS  PubMed  Google Scholar 

  103. Marintchev, A., Kolupaeva, V., Pestova, T. & Wagner, G. Mapping the binding interface between human eukaryotic initiation factors 1A and 5B: a new interaction between old partners. Proc. Natl. Acad. Sci. USA 100, 1535–1540 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  104. Szamecz, B. et al. eIF3a cooperates with sequences 5′ of uORF1 to promote resumption of scanning by post-termination ribosomes for reinitiation on GCN4 mRNA. Genes Dev. 22, 2414–2425 (2008). Identifies a role for eIF3 in scanning and reinitiation in vivo.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  105. Pöyry, T.A.A., Kaminski, A., Connell, E.J., Fraser, C.S. & Jackson, R.J. The mechanism of an exceptional case of reinitiation after translation of a long ORF reveals why such events do not generally occur in mammalian mRNA translation. Genes Dev. 21, 3149–3162 (2007).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  106. Ben-Shem, A. et al. The structure of the eukaryotic ribosome at 3.0 Å resolution. Science 334, 1524–1529 (2011).

    Article  CAS  PubMed  Google Scholar 

  107. You, T., Coghill, G.M. & Brown, A.J.P. A quantitative model for mRNA translation in Saccharomyces cerevisiae. Yeast 27, 785–800 (2010).

    Article  CAS  PubMed  Google Scholar 

  108. You, T., Stansfield, I., Romano, M.C., Brown, A.J.P. & Coghill, G.M. Analysing GCN4 translational control in yeast by stochastic chemical kinetics modelling and simulation. BMC Syst. Biol. 5, 131 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA

    Colin Echeverría Aitken & Jon R Lorsch

Authors
  1. Colin Echeverría Aitken
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jon R Lorsch
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding authors

Correspondence to Colin Echeverría Aitken or Jon R Lorsch.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Aitken, C., Lorsch, J. A mechanistic overview of translation initiation in eukaryotes. Nat Struct Mol Biol 19, 568–576 (2012). https://doi.org/10.1038/nsmb.2303

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nsmb.2303

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing