The 4E-BP-eIF4E axis promotes rapamycin-sensitive growth and proliferation in lymphocytes

Related Experiment Video

Updated: Mar 20, 2026

Monitoring eIF4F Assembly by Measuring eIF4E-eIF4G Interaction in Live Cells
08:47

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

Published on: May 1, 2020

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Lomon So1, Jongdae Lee2, Miguel Palafox1

  • 1Department of Molecular Biology and Biochemistry, and Institute for Immunology, University of California, Irvine, Irvine, CA 92697, USA.

Science Signaling
|June 2, 2016
PubMed

Insights

Rapamycin targets the 4E-BP-eIF4E pathway in lymphocytes, controlling both cell growth and proliferation. This pathway, not S6Ks, is key to rapamycin's immunosuppressive effects on lymphocytes.

Area of Science:

  • Immunology
  • Molecular Biology
  • Cell Biology

Background:

  • Rapamycin is a clinical immunosuppressant with unclear molecular mechanisms in lymphocytes.
  • Mammalian target of rapamycin (mTOR) signaling involves effectors like S6 kinases (S6Ks) and 4E-binding proteins (4E-BPs).
  • S6Ks are linked to cell growth, and 4E-BPs to proliferation, with mTORC1 integrating these functions.

Purpose of the Study:

  • To elucidate the molecular basis of rapamycin's selective immunosuppressive effects on lymphocytes.
  • To investigate the distinct roles of S6Ks and 4E-BPs in lymphocyte growth and proliferation.
  • To determine the specific signaling axis responsible for rapamycin's action in lymphocytes.

Main Methods:

  • Investigated the roles of S6Ks and 4E-BPs in lymphocyte signaling.
  • Analyzed the impact of rapamycin on eIF4E function in lymphocytes.
  • Assessed the relative abundance and sensitivity of 4E-BP1 and 4E-BP2 to rapamycin.

Main Results:

  • The 4E-BP-eIF4E signaling axis, not S6Ks, controlled both lymphocyte growth and proliferation.
  • Rapamycin selectively disrupted eIF4E function in lymphocytes.
  • Increased 4E-BP2 abundance and its higher sensitivity to rapamycin were observed in lymphocytes.

Conclusions:

  • The 4E-BP-eIF4E axis is uniquely sensitive to rapamycin in lymphocytes.
  • This axis coordinates lymphocyte growth and proliferation, driving clonal expansion.
  • Understanding this pathway offers insights into rapamycin's immunosuppressive action.

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