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Structural Determinants of MiRNAs for RISC Loading and Slicer-independent Unwinding

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Date 2009 Aug 18
PMID 19684602
Citations 146
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Abstract

MicroRNAs (miRNAs) regulate expression of their target mRNAs through the RNA-induced silencing complex (RISC), which contains an Argonaute (Ago) family protein as a core component. In Drosophila melanogaster, miRNAs are generally sorted into Ago1-containing RISC (Ago1-RISC). We established a native gel system that can biochemically dissect the Ago1-RISC assembly pathway. We found that miRNA-miRNA* duplexes are loaded into Ago1 as double-stranded RNAs in an ATP-dependent fashion. In contrast, unexpectedly, unwinding of miRNA-miRNA* duplexes is a passive process that does not require ATP or slicer activity of Ago1. Central mismatches direct miRNA-miRNA* duplexes into pre-Ago1-RISC, whereas mismatches in the seed or guide strand positions 12-15 promote conversion of pre-Ago1-RISC into mature Ago1-RISC. Our findings show that unwinding of miRNAs is a precise mirror-image process of target recognition, and both processes reflect the unique geometry of RNAs in Ago proteins.

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References
1.
Liu Q, Rand T, Kalidas S, Du F, Kim H, Smith D . R2D2, a bridge between the initiation and effector steps of the Drosophila RNAi pathway. Science. 2003; 301(5641):1921-5. DOI: 10.1126/science.1088710. View

2.
Eulalio A, Huntzinger E, Izaurralde E . GW182 interaction with Argonaute is essential for miRNA-mediated translational repression and mRNA decay. Nat Struct Mol Biol. 2008; 15(4):346-53. DOI: 10.1038/nsmb.1405. View

3.
Ishizuka A, Siomi M, Siomi H . A Drosophila fragile X protein interacts with components of RNAi and ribosomal proteins. Genes Dev. 2002; 16(19):2497-508. PMC: 187455. DOI: 10.1101/gad.1022002. View

4.
Rand T, Petersen S, Du F, Wang X . Argonaute2 cleaves the anti-guide strand of siRNA during RISC activation. Cell. 2005; 123(4):621-9. DOI: 10.1016/j.cell.2005.10.020. View

5.
Tomari Y, Du T, Zamore P . Sorting of Drosophila small silencing RNAs. Cell. 2007; 130(2):299-308. PMC: 2841505. DOI: 10.1016/j.cell.2007.05.057. View