Recognizes and binds the 7-methylguanosine-containing mRNA cap during an early step in the initiation of protein synthesis and facilitates ribosome binding by inducing the unwinding of the mRNAs secondary structures. All 5 eIF4E proteins bind monomethyl cap structures. Only ife-1, ife-2 and ife-5 bind trimethyl cap structures which result from trans-splicing. Translation of trimethyl cap structure mRNAs may be regulated by intracellular redox state; disulfide bonds change the width and depth of the cap-binding cavity determining selectivity to mRNA caps (PubMed:10744754, PubMed:9553113). Probably by regulating mRNA translation in somatic cells, negatively regulates lifespan independently of daf-2/insulin and let-363/TOR pathways (PubMed:17277769). Negatively regulates resistance to oxidative stress (PubMed:17277769). May play a role in embryonic development (PubMed:17277769). eIF4F is a multi-subunit complex, the composition of which varies with external and internal environmental conditions. It is composed of at least eIF4A, eIF4E and eIF4G. eIF4E is also known to interact with other partners. Highly expressed in all somatic tissues. Expressed at the 2-fold embryonic stage and throughout larval stages and adulthood. RNAi-mediated knockdown increases lifespan. Lifespan is further increased in an age-1 hx546, daf-2 e1370, clk-1 qm30 or eat-2 ad465 mutant background. Belongs to the eukaryotic initiation factor 4E family.