4E-BP restrains eIF4E phosphorylation.
Translation (Austin)
; 1(2): e25819, 2013.
Article
en En
| MEDLINE
| ID: mdl-26824022
In eukaryotes, mRNA translation is dependent on the cap-binding protein eIF4E. Through its simultaneous interaction with the mRNA cap structure and with the ribosome-associated eIF4G adaptor protein, eIF4E physically posits the ribosome at the 5' extremity of capped mRNA. eIF4E activity is regulated by phosphorylation on a unique site by the eIF4G-associated kinase MNK. eIF4E assembly with the eIF4G-MNK sub-complex can be however antagonized by the hypophosphorylated forms of eIF4E-binding protein (4E-BP). We show here that eIF4E phosphorylation is dramatically affected by disruption of eIF4E-eIF4G interaction, independently of changes in MNK expression. eIF4E phosphorylation is actually strongly downregulated upon eIF4G shutdown or upon sequestration by hypophosphorylated 4E-BP, consequent to mTOR inhibition. Downregulation of 4E-BP renders eIF4E phosphorylation insensitive to mTOR inhibition. These data highlight the important role of 4E-BP in regulating eIF4E phosphorylation independently of changes in MNK expression.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Translation (Austin)
Año:
2013
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Estados Unidos