High impact information on Eif4e

• Exit from M phase seems to require deadenylation and subsequent translational silencing of cyclin B1 mRNA by Maskin, a CPEB and eIF4E binding factor, whose expression is cell cycle regulated [1].
• The microinjection of messenger RNA encoding the eukaryotic translation initiation factor 4E (eIF-4E) into early embryos of Xenopus laevis leads to the induction of mesoderm in ectodermal explants [2].
• We show that X77K resides in a cytoplasmic complex with eIF4E, CPEB (cytoplasmic polyadenylation element-binding protein), CPSF-100 and XGLD2, but is not required for cytoplasmic polyadenylation per se [3].
• We now show that cellular stresses such as arsenite, anisomycin and heat shock also result in increased phosphorylation of eIF4E, eIF4F complex formation and the association of PABP with eIF4G, in conditions under which the rate of protein synthesis is severely inhibited [4].
• The stress-induced changes in eIF4E phosphorylation were totally abrogated by the p38 mitogen-activated protein (MAP) kinase inhibitor SB203580, and were partly inhibited by the phosphoinositide 3-kinase inhibitor LY294002 and the mammalian target of rapamycin (mTOR) inhibitor rapamycin [4].

Biological context of Eif4e

• mRNA encoding the translation initiation factor eIF-4E is expressed early in Xenopus embryogenesis [5].
• However, eIF4E phosphorylation was unaffected by extracellular signal-regulated protein kinase (MAP kinase) inhibitor PD98059 [4].

Anatomical context of Eif4e

• Expression of the eIF-4E mRNA in Xenopus oocytes and embryos was examined by RT-PCR [5].
• The translation initiation factor eIF-4E plays an important role in regulating the overall rate of translation in eukaryotic cells [5].

References