What is eif4?

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.

What is the function of eIF4F?

Functions of the constituent proteins of eIF4F include recognition of the mRNA 5′ cap structure (eIF4E), delivery of an RNA helicase to the 5′ region (eIF4A), bridging of the mRNA and the ribosome (eIF4G), and circularization of the mRNA via interaction with poly(A)-binding protein (eIF4G).

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.

Which initiation factor acts as a scaffold?

Eukaryotic initiation factor
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 are the other subunits of eIF4F?

The other subunits of eIF4F are a 47-kD polypeptide, termed eIF4A, that possesses ATPase and RNA helicase activities, and a 220-kD scaffolding polypeptide, eIF4G. Some viruses cut eIF4G in such a way that the eIF4E binding site is removed and the virus is able to translate its proteins without eIF4E.

What kind of protein is the EIF4E gene?

Eukaryotic translation initiation factor 4E, also known as eIF4E, is a protein that in humans is encoded by the EIF4E gene. Most eukaryotic cellular mRNAs are blocked at their 5′-ends with the 7-methyl- guanosine five-prime cap structure, m7GpppX (where X is any nucleotide).

What is the role of eIF4G1 in translation initiation?

EIF4G1 eukaryotic translation initiation factor 4 gamma 1 [ (human)] Summary. The protein encoded by this gene is a component of the multi-subunit protein complex EIF4F. This complex facilitates the recruitment of mRNA to the ribosome, which is a rate-limiting step during the initiation phase of protein synthesis.

How is the regulation of eIF4E carried out?

Regulation of eIF4E may be achieved via three distinct mechanisms: transcription, phosphorylation, and inhibitory proteins. a. Regulation of eIF4E by Gene Expression