The influence of microRNAs and poly(A) tail length on endogenous mRNA-protein complexes

Genome Biol. 2017 Oct 31;18(1):211. doi: 10.1186/s13059-017-1330-z.


Background: All mRNAs are bound in vivo by proteins to form mRNA-protein complexes (mRNPs), but changes in the composition of mRNPs during posttranscriptional regulation remain largely unexplored. Here, we have analyzed, on a transcriptome-wide scale, how microRNA-mediated repression modulates the associations of the core mRNP components eIF4E, eIF4G, and PABP and of the decay factor DDX6 in human cells.

Results: Despite the transient nature of repressed intermediates, we detect significant changes in mRNP composition, marked by dissociation of eIF4G and PABP, and by recruitment of DDX6. Furthermore, although poly(A)-tail length has been considered critical in post-transcriptional regulation, differences in steady-state tail length explain little of the variation in either PABP association or mRNP organization more generally. Instead, relative occupancy of core components correlates best with gene expression.

Conclusions: These results indicate that posttranscriptional regulatory factors, such as microRNAs, influence the associations of PABP and other core factors, and do so without substantially affecting steady-state tail length.

Keywords: MicroRNAs; Poly(A) tail; mRNA–protein complexes.

MeSH terms

  • Animals
  • Drosophila
  • HEK293 Cells
  • Humans
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Poly A / metabolism*
  • Polyadenylation
  • Protein Binding
  • Protein Biosynthesis
  • RNA Stability
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism*
  • Ribonucleoproteins / metabolism*
  • Saccharomyces cerevisiae / metabolism


  • MicroRNAs
  • RNA, Messenger
  • Ribonucleoproteins
  • messenger ribonucleoprotein
  • Poly A