R2D2, a Bridge Between the Initiation and Effector Steps of the Drosophila RNAi Pathway
Abstract
The RNA interference (RNAi) pathway is initiated by processing long double-stranded RNA into small interfering RNA (siRNA). The siRNA-generating enzyme was purified from Drosophila S2 cells and consists of two stoichiometric subunits: Dicer-2 (DCR-2) and a previously unknown protein that we named R2D2. R2D2 is homologous to the Caenorhabditis elegans RNAi protein RDE-4. Association with R2D2 does not affect the enzymatic activity of DCR-2. Rather, the DCR-2/R2D2 complex, but not DCR-2 alone, binds to siRNA and enhances sequence-specific messenger RNA degradation mediated by the RNA-initiated silencing complex (RISC). These results indicate that R2D2 bridges the initiation and effector steps of the Drosophila RNAi pathway by facilitating siRNA passage from Dicer to RISC.
- Publication:
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Science
- Pub Date:
- September 2003
- DOI:
- 10.1126/science.1088710
- Bibcode:
- 2003Sci...301.1921L
- Keywords:
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- MOLEC BIOL