EIF4G1
EIF4G1 (eukaryotic translation initiation factor 4 gamma 1, also known as p220, PARK18, EIF4G and EIF4F) is a large scaffolding component of the eIF4F complex. It helps recruit mRNA to the ribosome during the initiation of protein synthesis. Browse Assay Genie's current range of EIF4G1 research reagents below, or read on for the biology behind the target.
EIF4G1 is a component of the multi-subunit eIF4F complex, which is involved in recognition of the mRNA cap, ATP-dependent unwinding of 5'-terminal secondary structure and recruitment of mRNA to the ribosome. Recruitment of mRNA to the ribosome is a rate-limiting step in the initiation phase of protein synthesis. The EIF4G1 subunit is a large scaffolding protein with binding sites for other members of the eIF4F complex. Its N-terminal domain can also interact with the poly(A)-binding protein, which may mediate the circularisation of mRNA during translation.
The EIF4G1 protein exists in two mutually exclusive complexes, one with EIF1 and one with EIF4E. Together with EIF1, it is required for leaky scanning, in particular for avoiding a cap-proximal start codon. Together with EIF4E, it antagonises the scanning promoted by EIF1-EIF4G1 and locates the start codon through a TISU element without scanning. As a member of the eIF4F complex, it is also required for endoplasmic reticulum stress-induced translation of ATF4 mRNA.
The EIF4G1 gene belongs to the eukaryotic initiation factor 4G family and is classed by HGNC among the MIF4G domain containing proteins. Alternative splicing gives multiple transcript variants, some of which arise from alternative promoter usage. The protein localises to the cytoplasm, the nucleus and stress granules. The symbol PARK18 is among its recorded aliases, and the mouse ortholog is Eif4g1. Researchers often study EIF4G1 alongside EIF4E and EIF4A1 when examining cap-dependent translation.
EIF4G1 scaffolds the eIF4F complex that recognises the mRNA cap and recruits mRNA to the ribosome, a rate-limiting step in protein synthesis.
With EIF1 or EIF4E, EIF4G1 shapes leaky scanning and TISU-directed start codon location, making it central to studies of initiation fidelity.
As part of eIF4F, EIF4G1 is required for endoplasmic reticulum stress-induced ATF4 mRNA translation.
Its N-terminal interaction with poly(A)-binding protein may mediate mRNA circularisation, and the protein is found in stress granules.
EIF4G1 is a large scaffolding subunit of the eIF4F complex. The complex recognises the mRNA cap, unwinds 5'-terminal secondary structure in an ATP-dependent manner and recruits mRNA to the ribosome. It also binds poly(A)-binding protein, which may circularise mRNA during translation.
Recorded aliases include p220, PARK18, EIF4G and EIF4F. The previous HGNC name was eukaryotic translation initiation factor 4 gamma, 1. Alternative splicing produces multiple transcript variants, some from alternative promoter usage, so more than one transcript is annotated for the gene.
A mouse ortholog, Eif4g1, is recorded for the human gene. The protein belongs to the eukaryotic initiation factor 4G family. Cross-species work should confirm reagent reactivity, so check the datasheet of any product for its validated reactivity.
Other translation initiation factors, eIF4F partners and eIF2 kinases that act alongside EIF4G1 in the control of protein synthesis.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q04637; product specifications from Assay Genie datasheets.