Puromycin reactivity does not accurately localize translation at the subcellular level

Elife. 2020 Aug 26;9:e60303. doi: 10.7554/eLife.60303.


Puromycin is a tyrosyl-tRNA mimic that blocks translation by labeling and releasing elongating polypeptide chains from translating ribosomes. Puromycin has been used in molecular biology research for decades as a translation inhibitor. The development of puromycin antibodies and derivatized puromycin analogs has enabled the quantification of active translation in bulk and single-cell assays. More recently, in vivo puromycylation assays have become popular tools for localizing translating ribosomes in cells. These assays often use elongation inhibitors to purportedly inhibit the release of puromycin-labeled nascent peptides from ribosomes. Using in vitro and in vivo experiments in various eukaryotic systems, we demonstrate that, even in the presence of elongation inhibitors, puromycylated peptides are released and diffuse away from ribosomes. Puromycylation assays reveal subcellular sites, such as nuclei, where puromycylated peptides accumulate post-release and which do not necessarily coincide with sites of active translation. Our findings urge caution when interpreting puromycylation assays in vivo.

Keywords: C. elegans; biochemistry; cell biology; chemical biology; emetine; human; op-puro; puromycin; puromycylation; ribosome.

Publication types

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

MeSH terms

  • Animals
  • Caenorhabditis elegans
  • Cell Nucleus* / chemistry
  • Cell Nucleus* / metabolism
  • Emetine / metabolism
  • Emetine / pharmacology
  • Peptides / metabolism
  • Protein Biosynthesis* / drug effects
  • Protein Biosynthesis* / physiology
  • Protein Synthesis Inhibitors* / metabolism
  • Protein Synthesis Inhibitors* / pharmacology
  • Puromycin* / metabolism
  • Puromycin* / pharmacology
  • RNA, Transfer / metabolism
  • Rabbits
  • Ribosomes / metabolism
  • Single-Cell Analysis


  • Peptides
  • Protein Synthesis Inhibitors
  • Puromycin
  • RNA, Transfer
  • Emetine