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Isolation of Ribosome Bound Nascent Polypeptides in vitro to Identify Translational Pause Sites Along mRNA
10:15

Isolation of Ribosome Bound Nascent Polypeptides in vitro to Identify Translational Pause Sites Along mRNA

Published on: July 6, 2012

Cleavage of the A site mRNA codon during ribosome pausing provides a mechanism for translational quality control

Christopher S Hayes1, Robert T Sauer

  • 1Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

Molecular Cell
|October 29, 2003
PubMed

Insights

Bacterial ribosomes cleave mRNA during pausing, preventing harmful protein synthesis. This A site mRNA cleavage, linked to ribosome stalling, reduces translational errors and aberrant polypeptide production.

Area of Science:

  • Molecular Biology
  • Bacterial Protein Synthesis
  • Cellular Quality Control

Background:

  • Cells utilize intricate mechanisms for protein biosynthesis quality control.
  • Ribosome pausing is a critical event that can lead to errors in protein synthesis.

Purpose of the Study:

  • To investigate the fate of mRNA during bacterial ribosome pausing.
  • To elucidate the mechanism and implications of mRNA cleavage in response to translational stress.

Main Methods:

  • Assaying ribosome pausing using tmRNA-mediated tagging.
  • Quantifying A site mRNA cleavage during translation.
  • Investigating the requirement of specific factors (tmRNA, (p)ppGpp, RelE) for cleavage.

Main Results:

  • mRNA is cleaved at or near the A site codon during bacterial ribosome pausing.
  • The degree of mRNA cleavage correlates with the extent of ribosome pausing.
  • Cleavage is translation-dependent and does not require tmRNA, (p)ppGpp, or RelE.

Conclusions:

  • A site mRNA cleavage is a ribosome-mediated response to translational pausing.
  • This mechanism acts in concert with the tmRNA system to minimize errors in protein synthesis.
  • It effectively reduces the production of aberrant polypeptides under compromised conditions.

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