Abstract
The RNase III enzyme Dicer processes RNA into siRNAs and miRNAs, which direct a RNA-induced silencing complex (RISC) to cleave mRNA or block its translation (RNAi). We have characterized mutations in the Drosophila dicer-1 and dicer-2 genes. Mutation in dicer-1 blocks processing of miRNA precursors, whereas dicer-2 mutants are defective for processing siRNA precursors. It has been recently found that Drosophila Dicer-1 and Dicer-2 are also components of siRNA-dependent RISC (siRISC). We find that Dicer-1 and Dicer-2 are required for siRNA-directed mRNA cleavage, though the RNase III activity of Dicer-2 is not required. Dicer-1 and Dicer-2 facilitate distinct steps in the assembly of siRISC. However, Dicer-1 but not Dicer-2 is essential for miRISC-directed translation repression. Thus, siRISCs and miRISCs are different with respect to Dicers in Drosophila.
| Original language | English |
|---|---|
| Pages (from-to) | 69-81 |
| Number of pages | 13 |
| Journal | Cell |
| Volume | 117 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2004 Apr 2 |
| Externally published | Yes |
Bibliographical note
Funding Information:We thank Barry Dickson, Jim Posakony, David Gubb, Jean Louis Reichhart, and Bloomington and Szeged Stock Centers for fly strains; Xiaodong Wang and the Developmental Studies Hybridoma Bank for antibodies; Kristen Barry, Greg Sabino, Jeff Gorra, and Emily Hagan for help with flywork; Takashi Hayashi and the Northwestern Biological Imaging Facility for help with immunohistochemistry and microscopy. Y.S.L. is supported by a FRAXA postdoctoral fellowship; R.W.C. and E.S. are supported by the NIH.
ASJC Scopus subject areas
- General Biochemistry,Genetics and Molecular Biology