What is the function of elF4E?
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.
Which eukaryotic initiation factor is known as cap binding protein?
eIF-4E
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 do cell Signalling pathways control the activity of eIF4E in health and disease?
eIF4E amounts and activity are regulated by multiple mechanisms. These include: (1) amplification of the gene encoding eIF4E; (2) transcriptional activation, particularly by c-Myc; (3) control of eIF4E activity by eIF4E-binding proteins (4E-BPs) and (4) post-translational modifications such as phosphorylation [12].
How many initiation factors are in eukaryotes?
In eukaryotes, at least eleven different initiation factors are required to properly initiate translation. Collectively, they ensure that the methionyl-initiator tRNA (Met-tRNAiMet) is brought in the P site of the ribosome to the initiator AUG of an mRNA.
What happens when eIF4E is phosphorylated?
eIF4E phosphorylation is catalyzed by mitogen-activated protein kinase (MAPK)-interacting serine/threonine kinase (Mnk), a substrate of Erk1/2 and p38 MAPKs. Interaction with the scaffolding protein eIF4G, which also binds eIF4E, brings Mnk and its substrate into physical proximity.
What are Shine Dalgarno and Kozak sequences?
The Shine-Dalgarno sequence is a ribosomal binding site found commonly in bacterial but rarely in archeal mRNA. The Kozak sequence is a protein translation initiation site in eukaryotic mRNA. Discovered by. It was discovered by John Shine and Lynn Dalgarno. It was discovered by Marilyn Kozak.
Where is Kozak sequence located?
A feature specific to eukaryotic mRNA is the Kozak sequence [6], which extends from approximately position −6 to position +6, where +1 is assigned to the adenine of the START codon (throughout the present paper, all positions are given respective to the START codon).
What is role of eIF2 in protein synthesis after it is activated by eIF2B?
eIF2 binds initiator tRNA to ribosomes and promotes mRNA AUG codon recognition. eIF2B is critical for regulation of protein synthesis via a conserved mechanism of phosphorylation of eIF2, which converts eIF2 from a substrate to an inhibitor of eIF2B GEF.
What does phosphorylation of eIF2 do?
Phosphorylated eIF2 acts as a dominant inhibitor of the guanine nucleotide exchange factor eIF2B and prevents the recycling of eIF2 between successive rounds of protein synthesis.
What is the function of eIF4E in protein synthesis?
The cap-binding translation initiation factor eIF4E (eukaryotic initiation factor 4E) is central to protein synthesis in eukaryotes. As an integral component of eIF4F, a complex also containing the large bridging factor eIF4G and eIF4A RNA helicase, eIF4E enables the recruitment of the small ribosomal subunit to the 5′ end of mRNAs.
Can biphenyl inhibitors of eIF4E target internal binding sites?
A biphenyl inhibitor of eIF4E targeting an internal binding site enables the design of cell-permeable PROTAC-degraders The eukaryotic translation initiation factor 4E (eIF4E) is the master regulator of cap-dependent protein synthesis.
Can eIF4E binding protein 1 expression predict survival in colorectal cancer?
eIF4E binding protein 1 expression is associated with clinical survival outcomes in colorectal cancer NCBI Skip to main content Skip to navigation Resources How To About NCBI Accesskeys My NCBISign in to NCBISign Out PMC US National Library of Medicine National Institutes of Health
Is eIF4E the master regulator of cap-dependent protein synthesis?
DOI: 10.1016/j.ejmech.2021.113435 Abstract The eukaryotic translation initiation factor 4E (eIF4E) is the master regulator of cap-dependent protein synthesis.