Eukaryotic translation initiation factor 1A, X-chromosomal (EIF1AX)
The protein contains 144 amino acids for an estimated molecular weight of 16460 Da.
Seems to be required for maximal rate of protein biosynthesis. Enhances ribosome dissociation into subunits and stabilizes the binding of the initiator Met-tRNA(I) to 40 S ribosomal subunits. (updated: Oct. 10, 2018)
Protein identification was indicated in the following studies:
- 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.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
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.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
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.
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The reference OMIM entry for this protein is 300186
Eukaryotic translation initiation factor 1a, x-linked; eif1ax
Eukaryotic translation initiation factor 1a; eif1a
Eukaryotic translation initiation factor 4c; eif4c
CLONING
The small eukaryotic initiation factor eIF4C is implicated in the translation initiation pathway, where it enhances ribosome dissociation into subunits and stabilizes the binding of the initiator Met-tRNA to 40S ribosomal subunits. Dever et al. (1994) purified rabbit eIF4C and determined its amino acid sequence. By PCR with degenerate primers based on the rabbit eIF4C sequence, they isolated a partial human leukemia cDNA encoding eIF4C. They screened a leukemia cDNA library with the partial cDNA and obtained additional clones corresponding to the entire human eIF4C coding region. The sequence of the predicted 144-amino acid human protein was identical to that of rabbit eIF4C except in a single position. The human protein had an unblocked N-terminal proline, which Dever et al. (1994) stated was consistent with the general pattern of eukaryotic protein processing that removes an initiating methionine when it is followed by a proline. Sequence analysis revealed that eIF4C has a polar structure, with 9 of the first 15 amino acids being basic and 13 of the last 20 amino acids being acidic. The authors suggested that the dipole nature of the protein may allow it to interact with 2 different types of surfaces, perhaps functioning as a bridge between 2 initiation factors or between an initiation factor and the ribosome.BIOCHEMICAL FEATURES
- Crystal Structure Lomakin and Steitz (2013) determined the crystal structures of 3 complexes of the small ribosomal subunit 40S that represent distinct steps in mammalian translation initiation. These structures revealed the location of eIF1, eIF1A, mRNA, and initiator transfer RNA (see 180621) bound to the small ribosomal subunit and provided insights into the details of translation initiation specific to eukaryotes. Conformational changes associated with the captured functional states revealed the dynamics of the interactions of the P site of the ribosome.MAPPING
Lahn and Page (1997) mapped the EIF1A gene to the X chromosome by analysis of a somatic cell hybrid panel. They designated this gene EIF1AX to distinguish it from the Y-linked homolog, EIF1AY (400014). Lahn and Page (1997) determined that the EIF1AX gene escapes X inactivation, and proposed that it should be investigated as a candidate gene for Turner syndrome. See 400010. ... More on the omim web site
Oct. 19, 2018: Protein entry updated
Automatic update: OMIM entry 300186 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).