Function:Component of the protein complex eIF4F , which is involved in the recognition of the mRNA cap , ATP-dependent unwinding of 5'-terminal secondary structure and recruitment of mRNA to the ribosome. ,PTM:Following infection by certain enteroviruses , rhinoviruses and aphthoviruses , EIF4G1 is cleaved by the viral protease 2A , or the leader protease in the case of aphthoviruses. This shuts down the capped cellular mRNA transcription. ,PTM:Phosphorylated at multiple sites in vivo. ,sequence Caution:Aberrant splicing. ,similarity:Belongs to the eIF4G family. ,similarity:Contains 1 MI domain. ,similarity:Contains 1 MIF4G domain. ,similarity:Contains 1 W2 domain. ,subunit: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 EIF4G1/EIF4G3. Interacts with eIF3 , mutually exclusive with EIF4A1 or EIFA2 , EIF4E and through its N-terminus with PAPBC1. Interacts through its C-terminus with the serine/threonine kinases MKNK1 , and with MKNK2. Appears to act as a scaffold protein , holding these enzymes in place to phosphorylate EIF4E. Non-phosphorylated EIF4EBP1 competes with EIF4G1/EIF4G3 to interact with EIF4E; insulin stimulated MAP-kinase (MAPK1 and MAPK3) phosphorylation of EIF4EBP1 causes dissociation of the complex allowing EIF4G1/EIF4G3 to bind and consequent initiation of translation. EIF4G1/EIF4G3 interacts with PABPC1 to bring about circularization of the mRNA. Rapamycin can attenuate insulin stimulation mediated by FKBPs. Interacts with EIF4E3. Interacts with MIF4GD. Interacts with rotavirus A NSP3; in this interaction , NSP3 takes the place of PABPC1 thereby inducing shutoff of host protein synthesis. ,
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