Biochemical specialization within Arabidopsis RNA silencing pathways

Mol Cell. 2005 Aug 5;19(3):421-8. doi: 10.1016/j.molcel.2005.06.014.


In plants, the RNA silencing machinery responds to numerous inputs, including viral infection, microRNAs, and endogenous siRNAs that may act both in trans and in cis. Additionally, the full spectrum of silencing outcomes has been demonstrated in plants, ranging from mRNA degradation to repression at the level of protein synthesis to chromatin remodeling. Genetic studies in Arabidopsis have indicated that individual response pathways are functionally compartmentalized. However, to date, no biochemical systems have been available to investigate the roles of specific proteins within silencing pathways or the effects of selected mutations on the biochemical activity of those components. Here, we describe the generation of Arabidopsis extracts that reproduce many aspects of RNA silencing reactions in vitro. We find that specific members of the Dicer and Argonaute families have distinct biochemical activities, which provides insight into their roles within RNA silencing pathways in Arabidopsis.

Publication types

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

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Argonaute Proteins
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • Mutation
  • Plant Extracts / metabolism
  • RNA Interference*
  • RNA, Double-Stranded / genetics
  • RNA, Double-Stranded / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • RNA-Induced Silencing Complex / genetics
  • RNA-Induced Silencing Complex / metabolism
  • Ribonuclease III / genetics
  • Ribonuclease III / metabolism
  • Signal Transduction / genetics


  • AGO1 protein, Arabidopsis
  • Arabidopsis Proteins
  • Argonaute Proteins
  • Cell Cycle Proteins
  • MicroRNAs
  • Plant Extracts
  • RNA, Double-Stranded
  • RNA, Messenger
  • RNA, Small Interfering
  • RNA-Induced Silencing Complex
  • Adenosine Triphosphate
  • DCL1 protein, Arabidopsis
  • Ribonuclease III