Authors
Tomari, YukihideMatranga, Christian B.
Haley, Benjamin
Martinez, Natalia Julia
Zamore, Phillip D.
UMass Chan Affiliations
Department of Biochemistry and Molecular PharmacologyGraduate School of Biomedical Sciences
Document Type
Journal ArticlePublication Date
2004-11-20Keywords
Animals; Dimerization; Drosophila; Drosophila Proteins; Light; Luciferases; Nucleic Acid Conformation; RNA Helicases; *RNA Interference; RNA, Double-Stranded; RNA, Small Interfering; RNA-Binding Proteins; RNA-Induced Silencing Complex; Superoxide Dismutase; Thermodynamics; UracilLife Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
To act as guides in the RNA interference (RNAi) pathway, small interfering RNAs (siRNAs) must be unwound into their component strands, then assembled with proteins to form the RNA-induced silencing complex (RISC), which catalyzes target messenger RNA cleavage. Thermodynamic differences in the base-pairing stabilities of the 5' ends of the two approximately 21-nucleotide siRNA strands determine which siRNA strand is assembled into the RISC. We show that in Drosophila, the orientation of the Dicer-2/R2D2 protein heterodimer on the siRNA duplex determines which siRNA strand associates with the core RISC protein Argonaute 2. R2D2 binds the siRNA end with the greatest double-stranded character, thereby orienting the heterodimer on the siRNA duplex. Strong R2D2 binding requires a 5'-phosphate on the siRNA strand that is excluded from the RISC. Thus, R2D2 is both a protein sensor for siRNA thermodynamic asymmetry and a licensing factor for entry of authentic siRNAs into the RNAi pathway.Source
Science. 2004 Nov 19;306(5700):1377-80. Link to article on publisher's siteDOI
10.1126/science.1102755Permanent Link to this Item
http://hdl.handle.net/20.500.14038/32699PubMed ID
15550672; 15550672Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1126/science.1102755