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Updated: Aug 6, 2025

Eukaryotic Polyribosome Profile Analysis
Published on: June 15, 2010
A novel function for eukaryotic elongation factor 3: Inhibition of stop codon readthrough in yeast
Soushi Kobayashi1, Akira Kaji2, Hideko Kaji3
1Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA, 19104, USA; Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA.
Abstract:
Eukaryotic elongation factor 3 (eEF3) is one of the essential yeast ribosome-associated ATP-binding cassette type F (ABCF) ATPases. Previously, we found that eEF3 stimulates release of mRNA from puromycin-treated polysomes. In this study, we used a cell-free cricket paralysis virus (CrPV) internal ribosome entry site (IRES)-mediated firefly luciferase bicistronic mRNA translation system with yeast S30 extract. When eEF3 was partially removed from the crude extract, the product from the downstream ORF was increased by the readthrough of a UAA stop codon in the upstream ORF. eEF3 enhanced the release of luciferase from the polysome by eukaryotic release factor (eRF)1 and eRF3. These results suggest that eEF3 is a factor that assists eRFs in performing normal protein synthesis termination in yeast.
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