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DAP5 associates with eIF2β and eIF4AI to promote Internal Ribosome Entry Site driven translation

Noa Liberman1, Valentina Gandin2, Yuri V Svitkin3

  • 1Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 7610001, Israel nliberman@genetics.med.harvard.edu.

Nucleic Acids Research
|March 18, 2015
PubMed

Insights

DAP5 protein selectively stimulates Internal Ribosome Entry Site (IRES)-dependent mRNA translation by associating with eIF2β and eIF4AI. This protein is crucial for cap-independent translation initiation, especially during cellular stress.

Area of Science:

  • Molecular Biology
  • Gene Expression
  • Protein Synthesis

Background:

  • mRNA translation initiation is a critical regulatory step.
  • Cap-dependent translation relies on eIF4E; Internal Ribosome Entry Sites (IRESes) offer an alternative pathway.
  • Cap-independent translation is vital during cellular stress, mitosis, and viral infections.

Purpose of the Study:

  • To elucidate the role of DAP5 in mRNA translation.
  • To investigate DAP5's mechanism in regulating cap-dependent versus cap-independent translation.
  • To determine if DAP5 selectively controls specific translation pathways.

Main Methods:

  • Co-immunoprecipitation assays to detect protein-protein interactions.
  • Analysis of IRES-dependent and cap-dependent translation activity.
  • Investigating the association of DAP5 with translation factors eIF2β and eIF4AI.

Main Results:

  • DAP5 directly associates with translation factors eIF2β and eIF4AI.
  • DAP5 specifically enhances IRES-dependent translation of cellular mRNAs.
  • DAP5 is not required for cap-dependent translation initiation.

Conclusions:

  • DAP5 acts as a selective enhancer of cap-independent translation.
  • The findings reveal a novel mechanism for regulating IRES-mediated translation.
  • DAP5 plays a distinct role in cellular mRNA translation control, particularly under stress conditions.

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