Spatial Organization of Single mRNPs at Different Stages of the Gene Expression Pathway

Mol Cell. 2018 Nov 15;72(4):727-738.e5. doi: 10.1016/j.molcel.2018.10.010. Epub 2018 Nov 8.


mRNAs form ribonucleoprotein complexes (mRNPs) by association with proteins that are crucial for mRNA metabolism. While the mRNP proteome has been well characterized, little is known about mRNP organization. Using a single-molecule approach, we show that mRNA conformation changes depending on its cellular localization and translational state. Compared to nuclear mRNPs and lncRNPs, association with ribosomes decompacts individual mRNAs, while pharmacologically dissociating ribosomes or sequestering them into stress granules leads to increased compaction. Moreover, translating mRNAs rarely show co-localized 5' and 3' ends, indicating either that mRNAs are not translated in a closed-loop configuration, or that mRNA circularization is transient, suggesting that a stable closed-loop conformation is not a universal state for all translating mRNAs.

Keywords: RNA compaction; RNA imaging; RNA structure; closed-loop translation; long non-coding RNAs; mRNP organization; smFISH; stress granules; super resolution microscopy; translation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Exons
  • Gene Expression / physiology
  • HEK293 Cells
  • Humans
  • Protein Biosynthesis / physiology
  • RNA Precursors / genetics
  • RNA Precursors / physiology*
  • RNA Splicing
  • RNA Stability
  • RNA, Long Noncoding
  • RNA, Messenger / genetics
  • RNA, Messenger / ultrastructure
  • Ribonucleoproteins / genetics*
  • Ribonucleoproteins / physiology*
  • Ribosomes
  • Single Molecule Imaging / methods
  • Spatial Analysis


  • RNA Precursors
  • RNA, Long Noncoding
  • RNA, Messenger
  • Ribonucleoproteins
  • messenger ribonucleoprotein