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MicroRNAs direct rapid deadenylation of mRNA

Proc Natl Acad Sci U S A. 2006 Mar 14;103(11):4034-9. doi: 10.1073/pnas.0510928103. Epub 2006 Feb 22.

Abstract

MicroRNAs (miRNAs) are ubiquitous regulators of eukaryotic gene expression. In addition to repressing translation, miRNAs can down-regulate the concentration of mRNAs that contain elements to which they are imperfectly complementary. Using miR-125b and let-7 as representative miRNAs, we show that in mammalian cells this reduction in message abundance is a consequence of accelerated deadenylation, which leads to rapid mRNA decay. The ability of miRNAs to expedite poly(A) removal does not result from decreased translation; nor does translational repression by miRNAs require a poly(A) tail, a 3' histone stem-loop being an effective substitute. These findings suggest that miRNAs use two distinct posttranscriptional mechanisms to down-regulate gene expression.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Cell Line
  • Down-Regulation
  • Humans
  • Mice
  • MicroRNAs / chemistry
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Nucleic Acid Conformation
  • RNA Caps / metabolism
  • RNA Stability
  • RNA, Messenger / chemistry
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism*

Substances

  • MicroRNAs
  • RNA Caps
  • RNA, Messenger
  • mirnlet7 microRNA, human