Argonaute-bound small RNAs from promoter-proximal RNA polymerase II

Cell. 2014 Feb 27;156(5):920-34. doi: 10.1016/j.cell.2014.01.041.

Abstract

Argonaute (Ago) proteins mediate posttranscriptional gene repression by binding guide miRNAs to regulate targeted RNAs. To confidently assess Ago-bound small RNAs, we adapted a mouse embryonic stem cell system to express a single epitope-tagged Ago protein family member in an inducible manner. Here, we report the small RNA profile of Ago-deficient cells and show that Ago-dependent stability is a common feature of mammalian miRNAs. Using this criteria and immunopurification, we identified an Ago-dependent class of noncanonical miRNAs derived from protein-coding gene promoters, which we name transcriptional start site miRNAs (TSS-miRNAs). A subset of promoter-proximal RNA polymerase II (RNAPII) complexes produces hairpin RNAs that are processed in a DiGeorge syndrome critical region gene 8 (Dgcr8)/Drosha-independent but Dicer-dependent manner. TSS-miRNA activity is detectable from endogenous levels and following overexpression of mRNA constructs. Finally, we present evidence of differential expression and conservation in humans, suggesting important roles in gene regulation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Argonaute Proteins
  • Base Sequence
  • Cleavage And Polyadenylation Specificity Factor / metabolism
  • Embryonic Stem Cells / metabolism
  • Gene Expression Regulation*
  • Genetic Techniques
  • Humans
  • Mice
  • Promoter Regions, Genetic*
  • RNA Polymerase II / metabolism*
  • RNA, Small Untranslated / chemistry
  • RNA, Small Untranslated / genetics
  • RNA, Small Untranslated / metabolism*
  • Transcription Elongation, Genetic*
  • Transcription Initiation Site

Substances

  • Ago2 protein, mouse
  • Argonaute Proteins
  • Cleavage And Polyadenylation Specificity Factor
  • RNA, Small Untranslated
  • RNA Polymerase II

Associated data

  • GEO/GSE50595