EIF1 explained

Eukaryotic translation initiation factor 1 (eIF1) is a protein that in humans is encoded by the EIF1 gene. It is related to yeast SUI1.^{[1] [2] [3]}

eIF1 interacts with the eukaryotic small (40S) ribosomal subunit and eIF3, and is a component of the 43S preinitiation complex (PIC).^[4] eIF1 and eIF1A bind cooperatively to the 40S to stabilize an "open" conformation of the preinitiation complex (PIC) during eukaryotic translation initiation.^[4] eIF1 binds to a region near the ribosomal P-site in the 40S subunit and functions in a manner similar to the structurally related bacterial counterpart IF3.^[5]

Structure

eIF1 is a conserved translation protein in all eukaryotic cells that is responsible for the investigation of codon-anticodon mismatches during the initiation of translation. In order to determine the structure of human eIF1, an experiment with N-terminal His tag and eIF1 are conducted via using NMR spectroscopy. Scientists have discovered a binding site by generating yeast mutation and study the neighbor conserved residues located in the same region. GST pull-down experiments has shown that eIF1 binds precisely to the p110 subunit of eIF3 as a result explaining eIF1 recruiting. ^[6]

Function

The function of eIf1 has some hidden aspects. However, in all eukaryotic cells initiation of mRNA translation starts with scanning via ribosomal 43S preinitiation complexes starting from the 5’ end of the mRNA. Next, induction via eIF1 and eIF1A are needed to disclose the conformation of the 40S subunit in order to induce DEAD-box RNA helicase eIF4A, its cofactor eIF4B, and eIF4G activity.^[7]    

See also

• Eukaryotic initiation factors^[8]

Further reading

• Lian Z, Pan J, Liu J, Zhang S, Zhu M, Arbuthnot P, Kew M, Feitelson MA . The translation initiation factor, hu-Sui1 may be a target of hepatitis B X antigen in hepatocarcinogenesis . Oncogene . 18 . 9 . 1677–87 . March 1999 . 10208429 . 10.1038/sj.onc.1202470 . 22809502 . free .
• Fletcher CM, Pestova TV, Hellen CU, Wagner G . Structure and interactions of the translation initiation factor eIF1 . The EMBO Journal . 18 . 9 . 2631–7 . May 1999 . 10228174 . 1171342 . 10.1093/emboj/18.9.2631 .
• Chin LS, Singh SK, Wang Q, Murray SF . Identification of okadaic-acid-induced genes by mRNA differential display in glioma cells . Journal of Biomedical Science . 7 . 2 . 152–9 . 2000 . 10754390 . 10.1007/BF02256622 .
• Mendell JT, Medghalchi SM, Lake RG, Noensie EN, Dietz HC . Novel Upf2p orthologues suggest a functional link between translation initiation and nonsense surveillance complexes . Molecular and Cellular Biology . 20 . 23 . 8944–57 . December 2000 . 11073994 . 86549 . 10.1128/MCB.20.23.8944-8957.2000 .
• Rush J, Moritz A, Lee KA, Guo A, Goss VL, Spek EJ, Zhang H, Zha XM, Polakiewicz RD, Comb MJ . Immunoaffinity profiling of tyrosine phosphorylation in cancer cells . Nature Biotechnology . 23 . 1 . 94–101 . January 2005 . 15592455 . 10.1038/nbt1046 . 7200157 .

External links

• • • Cap-dependent translation initiation from Nature Reviews Microbiology. A good image and overview of the function of initiation factors

Notes and References

1. Fields C, Adams MD . Expressed sequence tags identify a human isolog of the suil translation initiation factor . Biochemical and Biophysical Research Communications . 198 . 1 . 288–91 . January 1994 . 7904817 . 10.1006/bbrc.1994.1040 .
2. Sheikh MS, Fernandez-Salas E, Yu M, Hussain A, Dinman JD, Peltz SW, Huang Y, Fornace AJ . Cloning and characterization of a human genotoxic and endoplasmic reticulum stress-inducible cDNA that encodes translation initiation factor 1(eIF1(A121/SUI1)) . The Journal of Biological Chemistry . 274 . 23 . 16487–93 . June 1999 . 10347211 . 10.1074/jbc.274.23.16487 . free .
3. Web site: Entrez Gene: EIF1 eukaryotic translation initiation factor 1.
4. Aitken CE, Lorsch JR . A mechanistic overview of translation initiation in eukaryotes . Nature Structural & Molecular Biology . 19 . 6 . 568–76 . June 2012 . 22664984 . 10.1038/nsmb.2303 . 9201095 .
5. Fraser CS . Quantitative studies of mRNA recruitment to the eukaryotic ribosome . Biochimie . 114 . 58–71 . July 2015 . 25742741 . 4458453 . 10.1016/j.biochi.2015.02.017 .
6. Fletcher CM, Pestova TV, Hellen CU, Wagner G . Structure and interactions of the translation initiation factor eIF1 . The EMBO Journal . 18 . 9 . 2631–7 . May 1999 . 10228174 . 1171342 . 10.1093/emboj/18.9.2631 .
7. Jackson RJ, Hellen CU, Pestova TV . The mechanism of eukaryotic translation initiation and principles of its regulation . En . Nature Reviews. Molecular Cell Biology . 11 . 2 . 113–27 . February 2010 . 20094052 . 10.1038/nrm2838 . 4461372 .
8. Web site: EIF1 - Eukaryotic translation initiation factor 1 - Homo sapiens (Human) - EIF1 gene & protein. www.uniprot.org. en. 2018-09-23.