eIF4

Eukaryotic translation initiation factor 4 (eIF4) is a translation initiation complex that regulates the recruitment of ribosomes to messenger RNA (mRNA) during cap-dependent protein synthesis[1][2]. The eIF4 complex consists primarily of eIF4E, eIF4A, and eIF4G, where eIF4E binds the 5′ mRNA cap structure, eIF4A functions as an RNA helicase, and eIF4G serves as a scaffold connecting translation initiation components[1][3]. Mechanistically, eIF4 activity controls translation initiation through regulation of mRNA circularization, ribosome recruitment, and scanning of the 5′ untranslated region[2][4]. Dysregulation of eIF4-dependent translation contributes to cancer development by promoting selective protein synthesis programs that support cell proliferation and survival[5]. In cancer models, increased eIF4E expression or enhanced eIF4E activity is associated with altered translation of growth-related mRNAs and tumor progression[5][6]. Compared with related translation initiation factors, eIF4E is distinguished by its specific recognition of the mRNA 5′ cap, whereas eIF4A and eIF4G perform helicase and scaffolding functions within the same initiation complex[1][3]. For experimental applications, genetic depletion of eIF4 components and pharmacological inhibition of eIF4E-eIF4G interaction are used to investigate translational regulation and disease-associated protein synthesis[6][7]. Small-molecule inhibitors targeting eIF4A or compounds disrupting eIF4E-mediated initiation have been developed as tools to study translation-dependent cellular processes and cancer biology[7][8].