Recognizes and binds the 7-methylguanosine-containing mRNA cap during an early step in the initiation. Acts as a repressor of translation initiation (PubMed:17368478, PubMed:22751931, PubMed:25624349, PubMed:33581076, PubMed:9582349). In contrast to EIF4E, it is unable to bind eIF4G (EIF4G1, EIF4G2 or EIF4G3), suggesting that it acts by competing with EIF4E and block assembly of eIF4F at the cap (By similarity). In P-bodies, component of a complex that promotes miRNA-mediated translational repression (PubMed:28487484). Involved in virus-induced host response by mediating miRNA MIR34A-induced translational silencing which controls IFNB1 production by a negative feedback mechanism (PubMed:28487484, PubMed:33581076). ; Component of the 4EHP-GYF2 complex, a multiprotein complex that acts as a repressor of translation initiation (PubMed:22751931, PubMed:35878012). In association with GIGYF2, assists ribosome-associated quality control (RQC) by sequestering the mRNA cap, blocking ribosome initiation and decreasing the translational load on problematic messages. Part of a pathway that works in parallel to RQC-mediated degradation of the stalled nascent polypeptide. GIGYF2 and EIF4E2 work downstream and independently of ZNF598, which seems to work as a scaffold that can recruit them to faulty mRNA even if alternative recruitment mechanisms may exist (PubMed:32726578). ; (Microbial infection) Upon SARS coronavirus-2/SARS-CoV-2 infection, the interaction with non-structural protein 2 (nsp2) with GIGYF2 enhances GIGYF2 binding to EIF4E2 and increases repression of translation initiation of genes involved in antiviral innate immune response such as IFNB1.
