Multiplexing polysome profiling experiments to study translation in Escherichia coli

PLoS One. 2019 Feb 19;14(2):e0212297. doi: 10.1371/journal.pone.0212297. eCollection 2019.

Abstract

Polysome profiling is a widely used method to monitor the translation status of mRNAs. Although it is theoretically a simple technique, it is labor intensive. Repetitive polysome fractionation rapidly generates a large number of samples to be handled in the downstream processes of protein elimination, RNA extraction and quantification. Here, we propose a multiplex polysome profiling experiment in which distinct cellular extracts are pooled before loading on the sucrose gradient for fractionation. We used the multiplexing method to study translation in E. coli. Multiplexing polysome profiling experiments provided similar mRNA translation status to that obtained with the non-multiplex method with comparable distribution of mRNA copies between the polysome profiling fractions, similar ribosome occupancy and ribosome density. The multiplexing method was used for parallel characterization of gene translational responses to changing mRNA levels. When the mRNA level of two native genes, cysZ and lacZ was increased by transcription induction, their global translational response was similar, with a higher ribosome load leading to increased ribosome occupancy and ribosome densities. However the pattern and the magnitude of the translational response were gene specific. By reducing the number of polysome profiling experiments, the multiplexing method saved time and effort and reduced cost and technical bias. This method would be useful to study the translational effect of mRNA sequence-dependent parameters that often require testing multiple samples and conditions in parallel.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions
  • Escherichia coli / genetics*
  • Escherichia coli / growth & development
  • Escherichia coli Proteins / genetics
  • Polyribosomes / genetics*
  • Polyribosomes / metabolism
  • Protein Biosynthesis
  • RNA, Messenger / isolation & purification
  • RNA, Messenger / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction / methods

Substances

  • 3' Untranslated Regions
  • Escherichia coli Proteins
  • RNA, Messenger

Grants and funding

HLN was supported by a pre-doctoral fellowship from INRA (french national institute for agricultural research). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.