Dicer-2 and R2D2 coordinately bind siRNA to promote assembly of the siRISC complexes

RNA. 2006 Aug;12(8):1514-20. doi: 10.1261/rna.101606. Epub 2006 Jun 14.

Abstract

In Drosophila melanogaster, the Dicer-2/R2D2 complex initiates RNA interference (RNAi) by processing long double-stranded RNA (dsRNA) into small interfering RNA (siRNA). Recent biochemical studies suggest that the Dcr-2/R2D2 complex also facilitates incorporation of siRNA into the RNA-induced silencing complex (siRISC). Here we present genetic evidence that R2D2 and Dcr-2 are both required for loading siRNA onto the siRISC complex. Consistent with this, only the Dcr-2/R2D2 complex, but neither Dcr-2 nor R2D2 alone, can efficiently interact with duplex siRNA. Furthermore, both dsRNA-binding domains of R2D2 are critical for binding to siRNA and promoting assembly of the siRISC complexes.

Publication types

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

MeSH terms

  • Animals
  • Drosophila Proteins / analysis
  • Drosophila Proteins / chemistry
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / metabolism
  • Histidine / chemistry
  • Homozygote
  • Insect Proteins / metabolism*
  • Open Reading Frames
  • Protein Structure, Tertiary
  • RNA Helicases / analysis
  • RNA Helicases / metabolism*
  • RNA, Double-Stranded / metabolism
  • RNA, Small Interfering / biosynthesis
  • RNA, Small Interfering / metabolism*
  • RNA-Binding Proteins / analysis
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • RNA-Induced Silencing Complex / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Ribonuclease III
  • Sequence Deletion
  • Thermodynamics
  • Transgenes

Substances

  • Drosophila Proteins
  • Insect Proteins
  • R2D2 protein, Drosophila
  • RNA, Double-Stranded
  • RNA, Small Interfering
  • RNA-Binding Proteins
  • RNA-Induced Silencing Complex
  • Recombinant Proteins
  • Histidine
  • DCR-2 protein, Drosophila
  • Ribonuclease III
  • RNA Helicases