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Updated: Dec 17, 2025

Monitoring eIF4F Assembly by Measuring eIF4E-eIF4G Interaction in Live Cells
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Non-cooperative 4E-BP2 folding with exchange between eIF4E-binding and binding-incompatible states tunes

Jennifer E Dawson1, Alaji Bah1,2, Zhenfu Zhang3

  • 1Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.

Nature Communications
|June 21, 2020
PubMed

Insights

Phosphorylation of intrinsically disordered 4E-BPs regulates translation. This study reveals how C-terminal phosphorylation of 4E-BP2 controls its binding to eIF4E through conformational changes, impacting translation initiation.

Area of Science:

  • Molecular Biology
  • Biochemistry
  • Cell Biology

Background:

  • Intrinsically disordered proteins (IDPs) like 4E-BPs regulate translation.
  • Phosphorylation of 4E-BPs alters their interaction with eIF4E, affecting cap-dependent translation.
  • Previous work showed T37/T46 phosphorylation in 4E-BP2 induces beta-fold domain formation.

Purpose of the Study:

  • To elucidate the mechanism of C-terminal intrinsically disordered region (C-IDR) phosphorylation in 4E-BP2.
  • To understand how C-IDR phospho-sites regulate eIF4E binding.
  • To investigate the role of non-cooperative folding and conformational exchange in 4E-BP2 function.

Main Methods:

  • Biochemical assays to study protein folding and conformational dynamics.
  • Analysis of phosphorylation sites and their impact on protein structure.
  • Investigating protein-protein interactions within the translation initiation complex.

Main Results:

  • The 4E-BP2 C-IDR exhibits non-cooperative folding with exchange between beta strands and helical conformations.
  • Phosphorylation of the C-IDR shifts the conformational equilibrium, modulating eIF4E binding.
  • Phosphorylated T37/T46 residues form stable hairpin turns, acting as transplantable units for phospho-regulation.

Conclusions:

  • Non-cooperative folding and conformational exchange in 4E-BP2 C-IDR lead to graded inhibition of eIF4E binding.
  • Phosphorylation drives 4E-BP2 into an eIF4E binding-incompatible conformation.
  • This mechanism provides a novel way to regulate translation initiation via 4E-BP2 phosphorylation.

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