Eukaryotic translation initiation factor 4B (EIF4B)

The protein contains 611 amino acids for an estimated molecular weight of 69151 Da.

 

Required for the binding of mRNA to ribosomes. Functions in close association with EIF4-F and EIF4-A. Binds near the 5'-terminal cap of mRNA in presence of EIF-4F and ATP. Promotes the ATPase activity and the ATP-dependent RNA unwinding activity of both EIF4-A and EIF4-F. (updated: March 4, 2015)

Protein identification was indicated in the following studies:

  1. Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
  2. Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
  3. Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
  4. Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
  5. D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.

Methods

The following articles were analysed to gather the proteome content of erythrocytes.

The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.

PublicationIdentification 1Uniprot mapping 2Not mapped /
Obsolete
TrEMBLSwiss-Prot
Goodman (2013)2289 (gene list)227853205992269
Lange (2014)123412347281224
Hegedus (2015)2638262202352387
Wilson (2016)165815281702911068
d'Alessandro (2017)18261817201815
Bryk (2017)20902060101081942
Chu (2018)18531804553621387

1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry

The compilation of older studies can be retrieved from the Red Blood Cell Collection database.

The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.

No sequence conservation computed yet.

Interpro domains
Total structural coverage: 0%
Model score: 0

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VariantDescription
Found in a renal cell carcinoma case; somatic mutation

The reference OMIM entry for this protein is 603928

Eukaryotic translation initiation factor 4b; eif4b

Eukaryotic translation initiation factor 4B (eIF4B) facilitates the binding of mRNA to the 43S preinitiation complex, which consists of the 40S ribosomal subunit bound to a ternary complex of eIF2, GTP, and Met-tRNA stabilized by eIF3 (see p66; 603915). eIF4F, a heterotrimeric protein, binds to the mRNA cap structure and, in combination with eIF4B, is thought to unwind the secondary structure in the 5-prime untranslated region of the mRNA to facilitate ribosome binding. Besides its RNA-binding activity, eIF4B stimulates the ATPase and RNA helicase activities of eIF4A (602641), one component of eIF4F (Methot et al. (1996)). By screening a fetal liver library with degenerate oligonucleotide probes based on the partial protein sequence of HeLa cell eIF4B, Milburn et al. (1990) isolated a partial cDNA encoding human eIF4B. They used the partial cDNA to screen an osteosarcoma library and recovered additional cDNAs corresponding to 2 distinct transcripts that had the same coding region but 3-prime ends of different lengths. Northern blot analysis revealed that eIF4B is expressed as 4.4- and 2.3-kb mRNAs in human cell lines. Milburn et al. (1990) determined that the 2 mRNAs differ by alternate utilization of polyadenylation signals. The predicted 611-amino acid eIF4B protein contains a consensus RNA-binding site (RNP-CS) near the N terminus, a central domain rich in aspartic acid, arginine, tyrosine, and glycine (DRYG-rich), and a C-terminal region with a large number of polar residues. The authors suggested that the highly polar DRYG region may account for the aberrant migration of eIF4B by SDS-PAGE: the factor has a predicted molecular weight of 70 kD, but an apparent molecular weight of 80 kD. Overexpression of eIF4B in mammalian cells inhibited translation. Southern blot analysis suggested that there are multiple eIF4B genes or pseudogenes in the human genome. Methot et al. (1994) determined that both the RNA recognition motif (RRM)/RNP-CS and a C-terminal RNA-binding region are essential for eIF4B function. Methot et al. (1996) demonstrated that the DRYG domain of eIF4B mediates self-association and interaction with the p170 (602039) subunit of eIF3. They proposed that eIF4B serves as a bridge between the mRNA and the 40S ribosomal subunit, by binding both mRNA and 18S ribosomal RNA. The direct interaction between eIF4B and eIF3, which is present on the 43S preinitiation complex prior to mRNA binding, provides an additional link between the mRNA and the ribosome. ... More on the omim web site

Subscribe to this protein entry history

May 12, 2019: Protein entry updated
Automatic update: model status changed

Nov. 17, 2018: Protein entry updated
Automatic update: model status changed

Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated

Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated

Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated

Oct. 27, 2017: Protein entry updated
Automatic update: model status changed

March 16, 2016: Protein entry updated
Automatic update: OMIM entry 603928 was added.

Jan. 24, 2016: Protein entry updated
Automatic update: model status changed