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Xenopus laevis as a Model to Identify Translation Impairment
Published on: September 27, 2015
Minimum requirements for the function of eukaryotic translation initiation factor 2.
F L Erickson1, J Nika, S Rippel
1Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083-0688, USA.
Genetics
|May 3, 2001
Summary
Increasing eukaryotic translation initiation factor 2 (eIF2) levels bypasses the need for eIF2B and eIF2alpha, suggesting the eIF2betagamma complex performs essential functions alone.
Area of Science:
- Molecular Biology
- Protein Synthesis
- Gene Regulation
Background:
- Eukaryotic translation initiation factor 2 (eIF2) facilitates tRNA delivery to ribosomes.
- eIF2B is the guanine nucleotide exchange factor essential for eIF2 function.
- eIF2alpha kinase PKR can be lethal when overexpressed.
Purpose of the Study:
- To investigate the essential functions of eIF2 subunits.
- To explore conditions that bypass the requirement for eIF2B and eIF2alpha.
- To understand the regulation of ternary complex levels.
Main Methods:
- In vivo experiments manipulating eIF2 levels and initiator tRNA.
- Utilizing a yeast model with specific eIF2 mutations (gcd11-K250R).
- Assessing the effects of PKR overexpression.
Main Results:
- Elevated wild-type eIF2 bypasses the need for eIF2B in vivo.
- These conditions suppress lethal PKR overexpression.
- Bypassing eIF2B also overcomes the requirement for the essential eIF2alpha gene (SUI2).
- A specific eIF2 mutation (gcd11-K250R) enhances these effects.
Conclusions:
- The eIF2betagamma complex can perform essential functions without eIF2alpha and eIF2B.
- eIF2B and eIF2alpha may primarily regulate ternary complex levels.
- This suggests a simplified model for translation initiation regulation.
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