Details

Autor(en) / Beteiligte

• Patrick, Ryan M.
• Lee, Jessica C.H.
• Teetsel, Jade R.J.
• Yang, Soo-Hyun
• Choy, Grace S.
• Browning, Karen S.

Titel

Discovery and characterization of conserved binding of eIF4E 1 (CBE1), a eukaryotic translation initiation factor 4E–binding plant protein

Ist Teil von

• The Journal of biological chemistry, 2018-11, Vol.293 (44), p.17240-17247

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2018

Quelle

MEDLINE

Beschreibungen/Notizen

• In many eukaryotes, translation initiation is regulated by proteins that bind to the mRNA cap–binding protein eukaryotic translation initiation factor 4E (eIF4E). These proteins commonly prevent association of eIF4E with eIF4G or form repressive messenger ribonucleoproteins that exclude the translation machinery. Such gene-regulatory mechanisms in plants, and even the presence of eIF4E-interacting proteins other than eIF4G (and the plant-specific isoform eIFiso4G, which binds eIFiso4E), are unknown. Here, we report the discovery of a plant-specific protein, conserved binding of eIF4E 1 (CBE1). We found that CBE1 has an evolutionarily conserved eIF4E-binding motif in its N-terminal domain and binds eIF4E or eIFiso4E in vitro. CBE1 thereby forms cap-binding complexes and is an eIF4E-dependent constituent of these complexes in vivo. Of note, plant mutants lacking CBE1 exhibited dysregulation of cell cycle–related transcripts and accumulated higher levels of mRNAs encoding proteins involved in mitosis than did WT plants. Our findings indicate that CBE1 is a plant protein that can form mRNA cap–binding complexes having the potential for regulating gene expression. Because mammalian translation factors are known regulators of cell cycle progression, we propose that CBE1 may represent such first translation factor–associated plant-specific cell cycle regulator.