Related Experiment Video
Updated: Jul 16, 2025
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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
Summary
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.
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