1. Biochemistry and Chemical Biology
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eIF1A residues implicated in cancer stabilize translation preinitiation complexes and favor suboptimal initiation sites in yeast

  1. Pilar Martin-Marcos
  2. Fujun Zhou
  3. Charm Karunasiri
  4. Fan Zhang
  5. Jinsheng Dong
  6. Jagpreet Nanda
  7. Neelam Sen
  8. Mercedes Tamame
  9. Michael Zeschnigk
  10. Jon R Lorsch  Is a corresponding author
  11. Alan G Hinnebusch  Is a corresponding author
  1. National Institutes of Health, United States
  2. Universidad de Salamanca, Spain
  3. University Duisburg-Essen, Germany
Research Article
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Cite this article as: eLife 2017;6:e31250 doi: 10.7554/eLife.31250
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Abstract

The translation pre-initiation complex (PIC) scans the mRNA for an AUG codon in favorable context, and AUG recognition stabilizes a closed PIC conformation. The unstructured N-terminal tail (NTT) of yeast eIF1A deploys five basic residues to contact tRNAi, mRNA, or 18S rRNA exclusively in the closed state. Interestingly, EIF1AX mutations altering the human eIF1A NTT are associated with uveal melanoma (UM). We found that substituting all five basic residues, and seven UM-associated substitutions, in yeast eIF1A suppresses initiation at near-cognate UUG codons and AUGs in poor context. Ribosome profiling of NTT substitution R13P reveals heightened discrimination against unfavorable AUG context genome-wide. Both R13P and K16D substitutions destabilize the closed complex at UUG codons in reconstituted PICs. Thus, electrostatic interactions involving the eIF1A NTT stabilize the closed conformation and promote utilization of suboptimal start codons. We predict UM-associated mutations alter human gene expression by increasing discrimination against poor initiation sites.

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Article and author information

Author details

  1. Pilar Martin-Marcos

    Laboratory on the Mechanism and Regulation of Protein Synthesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
    Competing interests
    No competing interests declared.
  2. Fujun Zhou

    Laboratory on the Mechanism and Regulation of Protein Synthesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
    Competing interests
    No competing interests declared.
  3. Charm Karunasiri

    Laboratory on the Mechanism and Regulation of Protein Synthesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
    Competing interests
    No competing interests declared.
  4. Fan Zhang

    Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
    Competing interests
    No competing interests declared.
  5. Jinsheng Dong

    Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
    Competing interests
    No competing interests declared.
  6. Jagpreet Nanda

    Laboratory on the Mechanism and Regulation of Protein Synthesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
    Competing interests
    No competing interests declared.
  7. Neelam Sen

    Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
    Competing interests
    No competing interests declared.
  8. Mercedes Tamame

    Instituto de Biología Funcional y Genómica (IBFG-CSIC)), Universidad de Salamanca, Salamanca, Spain
    Competing interests
    No competing interests declared.
  9. Michael Zeschnigk

    Institute of Human Genetics and Eye Cancer Research Group, University Duisburg-Essen, Essen, Germany
    Competing interests
    No competing interests declared.
  10. Jon R Lorsch

    Laboratory on the Mechanism and Regulation of Protein Synthesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
    For correspondence
    jon.lorsch@nih.gov
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4521-4999
  11. Alan G Hinnebusch

    Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
    For correspondence
    ahinnebusch@nih.gov
    Competing interests
    Alan G Hinnebusch, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1627-8395

Funding

National Institutes of Health (Intramural Research Program)

  • Alan G Hinnebusch

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Nahum Sonenberg, McGill University, Canada

Publication history

  1. Received: August 14, 2017
  2. Accepted: December 4, 2017
  3. Accepted Manuscript published: December 5, 2017 (version 1)
  4. Version of Record published: January 5, 2018 (version 2)

Copyright

This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

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