Abstract
Mammalian translation initiation factor 3 (eIF3) is a multisubunit complex containing at least 12 subunits with an apparent aggregate mass of ≈ 700 kDa. eIF3 binds to the 40S ribosomal subunit, promotes the binding of methionyl‐tRNAi and mRNA, and interacts with several other initiation factors to form the 40S initiation complex. Human cDNAs encoding 11 of the 12 subunits have been isolated previously; here we report the cloning and characterization of a twelfth subunit, a 28‐kDa protein named eIF3k. Evidence that eIF3k is present in the eIF3 complex was obtained. A monoclonal anti‐eIF3a (p170) Ig coimmunoprecipitates eIF3k with the eIF3 complex. Affinity purification of histidine‐tagged eIF3k from transiently transfected COS cells copurifies other eIF3 subunits. eIF3k colocalizes with eIF3 on 40S ribosomal subunits. eIF3k coexpressed with five other ‘core’ eIF3 subunits in baculovirus‐infected insect cells, forms a stable, immunoprecipitatable, complex with the ‘core’. eIF3k interacts directly with eIF3c, eIF3g and eIF3j by glutathione S‐transferase pull‐down assays. Sequences homologous with eIF3k are found in the genomes of Caenorhabitis elegans, Arabidopsis thaliana and Drosophila melanogaster, and a homologous protein has been reported to be present in wheat eIF3. Its ubiquitous expression in human tissues, yet its apparent absence in Saccharomyces cerevisiae and Schizosaccharomyces pombe, suggest a unique regulatory role for eIF3k in higher organisms. The studies of eIF3k complete the characterization of mammalian eIF3 subunits.
References
33
Referenced
47
{'key': 'e_1_2_13_2_2', 'first-page': '33', 'volume-title': 'Translational Control of Gene Expression', 'author': 'Hershey J.W.B.', 'year': '2000'}
/ Translational Control of Gene Expression by Hershey J.W.B. (2000)10.1074/jbc.274.25.17975
10.1074/jbc.270.37.21975
10.1074/jbc.M007525200
10.1038/35002118
10.1093/emboj/18.9.2631
10.1128/MCB.16.10.5328
10.1074/jbc.272.11.7106
10.1074/jbc.272.2.1110
10.1074/jbc.272.2.1101
10.1074/jbc.272.43.27042
10.1074/jbc.272.38.23477
10.1074/jbc.273.48.31901
10.1074/jbc.M104966200
10.1074/jbc.274.24.16802
10.1128/MCB.6.12.4419
10.1073/pnas.89.21.10355
10.1074/jbc.274.13.8546
10.1128/MCB.17.1.145
10.1074/jbc.274.39.27567
10.1101/gad.1065403
10.1021/bi00261a002
10.1021/bi00261a003
10.1006/meth.1996.0434
10.1016/0022-2836(87)90418-9
10.1016/S0021-9258(18)68497-2
/ J. Biol. Chem. / Cotranslational Amino‐terminal Processing of Cytosolic Proteins by Boissel J.‐P. (1988)10.1021/bi00399a033
- UCSC Genome Broswer (2002) http://genome.ucsc.edu(genome Human; assembley Nov.2002; position AF085358).
10.1101/gr.140200
10.1016/S0021-9258(18)32357-3
/ J. Biol. Chem. / Protein synthesis eukaryotic initiaiton factors 4A and 4B are not altered by poliovirus infection of HeLa cells by Duncan R. (1983)10.1089/dna.1997.16.515
10.1128/MCB.18.8.4935
10.1074/jbc.M007236200
Dates
Type | When |
---|---|
Created | 21 years, 10 months ago (Oct. 2, 2003, 7:24 p.m.) |
Deposited | 1 year, 10 months ago (Oct. 16, 2023, 5:05 p.m.) |
Indexed | 1 month, 1 week ago (July 16, 2025, 9:15 a.m.) |
Issued | 21 years, 10 months ago (Sept. 30, 2003) |
Published | 21 years, 10 months ago (Sept. 30, 2003) |
Published Online | 21 years, 10 months ago (Sept. 30, 2003) |
Published Print | 21 years, 10 months ago (Oct. 1, 2003) |
@article{Mayeur_2003, title={Characterization of eIF3k: A newly discovered subunit of mammalian translation initiation factor eIF3}, volume={270}, ISSN={1432-1033}, url={http://dx.doi.org/10.1046/j.1432-1033.2003.03807.x}, DOI={10.1046/j.1432-1033.2003.03807.x}, number={20}, journal={European Journal of Biochemistry}, publisher={Wiley}, author={Mayeur, Greg L. and Fraser, Christopher S. and Peiretti, Franck and Block, Karen L. and Hershey, John W. B.}, year={2003}, month=sep, pages={4133–4139} }