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Updated: Jul 19, 2026
08:23
De novo Identification of Actively Translated Open Reading Frames with Ribosome Profiling Data
Published on: February 18, 2022
her-2 upstream open reading frame effects on the use of downstream initiation codons
Christina C Spevak1, Eun-Hee Park, Adam P Geballe
1Department of Environmental and Biomolecular Systems, Oregon Health and Science University, Beaverton, OR 97006, USA.
Biochemical and Biophysical Research Communications
|October 19, 2006
Summary
An upstream open reading frame (uORF) in the HER2 gene transcript suppresses its translation. This uORF also influences ribosome binding and start-site selection during protein synthesis.
Area of Science:
- Molecular Biology
- Oncology
- Gene Regulation
Background:
- The human epidermal growth factor receptor 2 (HER2) oncogene is a transmembrane receptor tyrosine kinase.
- HER2 overexpression is implicated in 25-30% of human breast and ovarian cancers.
- Gene expression is regulated at multiple levels, including translation initiation.
Purpose of the Study:
- To investigate the role of an upstream open reading frame (uORF) in the HER2 transcript.
- To determine the impact of the HER2 uORF on protein translation and initiation.
- To analyze the mechanism by which the uORF affects translation.
Main Methods:
- Utilized synthetic mRNAs with HER2 5' region sequences fused to a firefly luciferase reporter.
- Assessed translational efficiency in cell-free systems (reticulocytes, wheat germ, Neurospora crassa) and RNA-transfected HeLa cells.
- Employed [(35)S]Met labeling and primer extension inhibition (toeprint) assays to analyze translation products and ribosome interactions.
Main Results:
- The HER2 uORF significantly reduced downstream cistron translation across all tested systems.
- The uORF was found to influence the selection of downstream start sites.
- Toeprint assays revealed that the uORF alters ribosome interaction with the primary HER2 AUG start codon.
Conclusions:
- The HER2 uORF acts as a negative regulator of HER2 protein synthesis.
- The uORF modulates translation initiation by affecting ribosome binding to the main start codon.
- Understanding this regulatory mechanism provides insights into HER2-driven oncogenesis.
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