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An Oligonucleotide-based Tandem RNA Isolation Procedure to Recover Eukaryotic mRNA-Protein Complexes
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An Oligonucleotide-based Tandem RNA Isolation Procedure to Recover Eukaryotic mRNA-Protein Complexes

Published on: August 18, 2018

The poly(A)-dependent degradation pathway of rpsO mRNA is primarily mediated by RNase R

José M Andrade1, Eliane Hajnsdorf, Philippe Régnier

  • 1Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.

RNA (New York, N.Y.)
|December 24, 2008
PubMed

Insights

RNase R is key for degrading polyadenylated RNA in Escherichia coli. This enzyme, unlike RNase II and PNPase, efficiently degrades mRNA with poly(A) tails, even overcoming RNA structures.

Area of Science:

  • Molecular Biology
  • Microbiology
  • RNA Metabolism

Background:

  • Polyadenylation regulates RNA degradation and quality control.
  • RNase II and PNPase are major Escherichia coli RNA exonucleases involved in mRNA decay.
  • Existing models could not fully explain poly(A)-dependent degradation of rpsO mRNA.

Purpose of the Study:

  • To investigate the role of RNase R in poly(A)-dependent RNA degradation in vivo.
  • To identify the primary enzyme responsible for degrading polyadenylated mRNA in Escherichia coli.
  • To elucidate the mechanism of poly(A) tail influence on mRNA decay pathways.

Main Methods:

  • Genetic analysis of Escherichia coli strains deficient in specific RNases (RNase R, RNase II, PNPase, RNase E).
  • Analysis of rpsO and rpsT mRNA degradation patterns and poly(A) tail lengths.
  • In vivo studies to assess the impact of RNase inactivation on transcript accumulation.

Main Results:

  • RNase R exhibits in vivo affinity for polyadenylated RNA and is crucial for poly(A)-dependent degradation of rpsO mRNA, especially in the absence of RNase E.
  • RNase R inactivation counteracts extended degradation of rpsO mRNA observed in RNase II-deficient cells.
  • Elongated poly(A) tails on rpsO transcripts specifically promote RNase R recognition and degradation, irrespective of RNA secondary structures or PNPase presence.

Conclusions:

  • RNase R is a key enzyme in poly(A) metabolism and the primary mediator of polyadenylated mRNA degradation in Escherichia coli.
  • Polyadenylation enhances the efficiency of RNase R-mediated RNA decay pathways in vivo.
  • The findings reveal a novel mechanism for mRNA quality control involving RNase R and poly(A) tails.

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