Eukaryotic translation initiation factor 3 subunit K (EIF3K)
The protein contains 218 amino acids for an estimated molecular weight of 25060 Da.
Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is required for several steps in the initiation of protein synthesis (PubMed:17581632, PubMed:25849773, PubMed:27462815). The eIF-3 complex associates with the 40S ribosome and facilitates the recruitment of eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to form the 43S pre-initiation complex (43S PIC). The eIF-3 complex stimulates mRNA recruitment to the 43S PIC and scanning of the mRNA for AUG recognition. The eIF-3 complex is also required for disassembly and recycling of post-termination ribosomal complexes and subsequently prevents premature joining of the 40S and 60S ribosomal subunits prior to initiation (PubMed:17581632). The eIF-3 complex specifically targets and initiates translation of a subset of mRNAs involved in cell proliferation, including cell cycling, differentiation and apoptosis, and uses different modes of RNA stem-loop binding to exert either translational activation or repression (PubMed:25849773). (updated: Oct. 25, 2017)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- 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.
- Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
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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Biological Process
Cellular protein metabolic process
Formation of cytoplasmic translation initiation complex
Formation of translation preinitiation complex
Gene expression
Regulation of translational initiation
Translation
Translational initiation
The reference OMIM entry for this protein is 609596
Eukaryotic translation initiation factor 3, subunit k; eif3k
Eif3-p28
Plac24
Eukaryotic translation initiation factor 3, subunit 12, formerly; eif3s12, formerly
DESCRIPTION
The 700-kD eukaryotic translation initiation factor-3 (eIF3) is the largest eIF and contains at least 12 subunits, including EIF2S12. eIF3 plays an essential role in translation by binding directly to the 40S ribosomal subunit and promoting formation of the 40S preinitiation complex (Mayeur et al., 2003).CLONING
Karki et al. (2002) isolated rat Eif3s12, which they called Plac24, by screening rat brain cytosol for cytoplasmic dynein intermediate chain (see 603772)-binding proteins. They obtained human EIF3S12 by searching an EST database using the rat sequence. The predicted human protein contains 218 amino acids. Northern blot analysis of human tissues showed ubiquitous expression of a 1-kb EIF3S12 transcript, with highest levels in heart and skeletal muscle. Western blot analysis detected EIF3S12 protein in all human tissues examined. By searching an EST database using the peptide sequence of a 28-kD protein purified from HeLa cell eIF3 complex as query, Mayeur et al. (2003) identified human EIF3S12, which they called EIF3K. EIF3S12 encodes a 218-amino acid protein composed of approximately 10% leucine residues. In vitro transcription/translation of EIF3S12 resulted in labeled protein that comigrated with the 28-kD protein found in eIF3 complex. Northern blot analysis detected ubiquitous expression of a 1.1-kb EIF3S12 transcript in human cell lines and tissues, with highest levels in brain, testis, and kidney.GENE FUNCTION
Karki et al. (2002) found that EIF3S12 did not coimmunoprecipitate with cytoplasmic dynein, indicating it is not a dynein subunit. However, affinity column binding and yeast 2-hybrid experiments showed direct binding between EIF3S12 and dynein intermediate chain. Immunohistochemistry experiments localized EIF3S12 to perinuclear cytoplasmic regions in isolated epithelial cells and fibroblasts. In epithelial cells, EIF3S12 localized to the cell surface at sites of cell-cell contact and colocalized with E-cadherin (CDH1; 192090) and beta-catenin (CTNNB1; 116806). Disruption of the actin cytoskeleton or overexpression of beta-catenin resulted in loss of EIF3S12 expression at sites of cell-cell contact. Using immunoprecipitation and isoelectric focusing, Mayeur et al. (2003) showed that EIF3S12 associated with the eIF3 complex. Immunoprecipitation of baculovirus-infected cells demonstrated that EIF3S12 associated with 5 core eIF3 subunits, and GST pull-down experiments revealed direct interactions between EIF3S12 and EIF3C (EIF3S8; 603916), EIF3G (EIF3S4; 603913), and EIF3J (EIF3S1; 603910). Cell fractionation experiments localized EIF3S12 in the region of the 40S ribosomal subunit. By yeast 2-hybrid analysis, Shen et al. (2004) identified EIF3S12 as a binding partner of cyclin D3 (CCND3; 123834). GST pull-down experiments and transient transfections showed that EIF3S12 and cyclin D3 bound both in vitro and in vivo, and EIF3S12 did not bind cyclin D1 (CCND1; 168461) or D2 (CCND2; 123833). Immunofluorescence revealed EIF3S12 distributed in the nucleus and cytoplasm in a pattern that overlapped with that of cyclin D3.GENE STRUCTURE
By genomic sequence analysis, Mayeur et al. (2003) determined that the EIF3S12 gene contains 8 exons.MAPPING
By genomic sequence analysis, Mayeur et al. (2003) mapped the EIF3S12 gene to chromosome 19q13.2. ... More on the omim web site
Feb. 10, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.
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
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 609596 was added.
Jan. 28, 2016: Protein entry updated
Automatic update: model status changed
Jan. 24, 2016: Protein entry updated
Automatic update: model status changed