Related Experiment Video

Updated: Jul 16, 2025

Monitoring eIF4F Assembly by Measuring eIF4E-eIF4G Interaction in Live Cells
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Monitoring eIF4F Assembly by Measuring eIF4E-eIF4G Interaction in Live Cells

Published on: May 1, 2020

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Yeast Tor complex 1 phosphorylates eIF4E-binding protein, Caf20

Yoshiaki Kamada1,2, Ryoko Ando3, Shingo Izawa3

  • 1National Institute for Basic Biology, Okazaki, Japan.

Genes to Cells : Devoted to Molecular & Cellular Mechanisms
|September 13, 2023
PubMed

Insights

This study shows that Tor complex 1 (TORC1) directly phosphorylates yeast

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Tor complex 1 (TORC1) regulates cell growth by controlling translation.
  • In mammals, mTORC1 phosphorylates 4E-BP1, affecting translation initiation.
  • The role of yeast 4E-BPs (Caf20, Eap1) in TORC1-mediated translation is unclear.

Purpose of the Study:

  • To investigate the regulation of yeast 4E-BP, Caf20, by TORC1.
  • To determine if TORC1 influences Caf20 phosphorylation and ribosome association.
  • To elucidate the role of the TORC1-4E-BP pathway in yeast translational control.

Main Methods:

  • In vivo analysis of Caf20 phosphorylation status.
  • In vitro kinase assays to assess direct TORC1 phosphorylation of Caf20.
  • Biochemical assays to detect TORC1-dependent Caf20 recruitment to ribosomes.

Main Results:

  • TORC1 influences the phosphorylation of Caf20 in vivo.
  • TORC1 directly phosphorylates Caf20 in vitro.
  • TORC1 mediates the recruitment of Caf20 to the 80S ribosome.

Conclusions:

  • Yeast 4E-BP, Caf20, is a direct substrate of TORC1.
  • TORC1-mediated phosphorylation and ribosome recruitment of Caf20 suggest its role in translation initiation.
  • This study clarifies the involvement of the TORC1-4E-BP axis in regulating yeast translational efficiency.
Keywords:
4E-BPTORC1Torsignal transductiontranslation initiationyeast

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