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Assessment of Selective mRNA Translation in Mammalian Cells by Polysome Profiling
Published on: October 28, 2014
28.9K
Profiling of terminating ribosomes reveals translational control at stop codons
Longfei Jia1,2,3, Yuanhui Mao1,4,3, Saori Uematsu1
1Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
Biorxiv : the Preprint Server for Biology
|September 26, 2025
Summary
Ribosome pausing at stop codons ensures protein synthesis accuracy. This study reveals sequence motifs and ribosome composition influence pausing, preventing errors like stop codon slippage and ensuring proteome integrity.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Protein synthesis termination is crucial for cellular proteome integrity.
- The dynamics and fidelity of terminating ribosomes are not fully understood.
Purpose of the Study:
- To profile terminating ribosomes in mammalian cells.
- To investigate the factors influencing ribosome pausing at stop codons.
- To understand the consequences of altered termination dynamics.
Main Methods:
- Profiling of terminating ribosomes in mammalian cells.
- Massively parallel reporter assays to confirm sequence motif effects.
- Analysis of mRNA:rRNA interactions and Rps26 stoichiometry.
Main Results:
- A wide range of ribosome pausing was observed at individual stop codons.
- An upstream sequence motif was identified that contributes to termination pausing.
- Lack of pausing increased stop codon slippage, leading to aberrant proteins.
- Sequence-dependent pausing results from 18S rRNA scanning of mRNA.
- Tissue-specific pausing correlates with Rps26 levels, affecting mRNA:rRNA interaction.
Conclusions:
- Termination pausing is a translational signature influenced by mRNA sequence, ribosome composition, and cell-specific control.
- This pausing mechanism is vital for maintaining protein synthesis fidelity.
- Findings provide insights into translational regulation and potential therapeutic targets.
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