What does eIF4E do?
eIF4E is a eukaryotic translation initiation factor involved in directing ribosomes to the cap structure of mRNAs. It is a 24-kD polypeptide that exists as both a free form and as part of the eIF4F pre-initiation complex. Almost all cellular mRNA require eIF4E in order to be translated into protein.
Is eIF4E an oncogene?
eIF4E is a potent oncogene elevated in up to 30% of human malignancies, including carcinomas of the breast, prostate, lung, head, and neck as well as in many leukemias and lymphomas (Crew and others 1996; Nathan and others 1997a; De Benedetti and Harris 1999; Crew and others 2000; Berkel and others 2001; Seki and …
Where does eIF4E bind to?
eIF4E binds the 7-methylguanosine cap at the 5′ end of mRNA. eIF4E recruits the scaffold protein eIF4G that in turn recruits the 40S ribosomal subunit to the mRNA. eIF4G can also bind other initiation factors including the RNA helicase eIF4A. The eIF4E/4G/4 A complex is called eIF4F.
Which eukaryotic initiation factor is known as cap-binding protein?
The mRNA cap-binding protein, eukaryotic initiation factor-4E (eIF-4E), recognizes the mRNA cap structure and regulates translation. Insulin activation induces the phosphorylation of serine in eIF-4E, which in turn increases the affinity of eIF-4E for the mRNA cap structure and increases translation.
How is translation initiated in eukaryotes?
Translation initiation is a complex process in which initiator tRNA, 40S, and 60S ribosomal subunits are assembled by eukaryotic initiation factors (eIFs) into an 80S ribosome at the initiation codon of mRNA.
What is the function of eEF2?
Eukaryotic elongation factor 2 (eEF2) is a GTP-binding protein that mediates the translocation of peptidyl-tRNA from the A site to the P site on the ribosome (Moldave, 1985).
Which initiation factor acts as a scaffold?
Eukaryotic initiation factor (eIF) 4G is an integral member of the translation initiation machinery. The molecule serves as a scaffold for several other initiation factors, including eIF4E, eIF4AI, the eIF3 complex, and poly(A)-binding protein (PABP).
What does poly A binding protein do?
Poly (A) tails are found at the 3′ ends of almost all eukaryotic mRNAs. They are bound by two different poly (A) binding proteins, PABPC in the cytoplasm and PABPN1 in the nucleus. PABPC functions in the initiation of translation and in the regulation of mRNA decay.