Title
Phosphate and R2D2 Restrict the Substrate Specificity of Dicer-2, an ATP-Driven Ribonuclease
UMMS Affiliation
Department of Biochemistry and Molecular Pharmacology
Publication Date
2011-03-16
Document Type
Article
Subjects
Drosophila Proteins; RNA Helicases; Ribonuclease III; RNA, Small Interfering; MicroRNAs; RNA, Double-Stranded; Adenosine Triphosphate; Substrate Specificity
Disciplines
Biochemistry, Biophysics, and Structural Biology | Pharmacology, Toxicology and Environmental Health
Abstract
Drosophila Dicer-2 generates small interfering RNAs (siRNAs) from long double-stranded RNA (dsRNA), whereas Dicer-1 produces microRNAs (miRNAs) from pre-miRNA. What makes the two Dicers specific for their biological substrates? We find that purified Dicer-2 can efficiently cleave pre-miRNA, but that inorganic phosphate and the Dicer-2 partner protein R2D2 inhibit pre-miRNA cleavage. Dicer-2 contains C-terminal RNase III domains that mediate RNA cleavage and an N-terminal helicase motif, whose function is unclear. We show that Dicer-2 is a dsRNA-stimulated ATPase that hydrolyzes ATP to ADP; ATP hydrolysis is required for Dicer-2 to process long dsRNA, but not pre-miRNA. Wild-type Dicer-2, but not a mutant defective in ATP hydrolysis, can generate siRNAs faster than it can dissociate from a long dsRNA substrate. We propose that the Dicer-2 helicase domain uses ATP to generate many siRNAs from a single molecule of dsRNA before dissociating from its substrate.
Keywords
Dicer-1, Dicer-2, R2D2, ATP, helicase, phosphate, processivity, substrate specificity
DOI of Published Version
10.1016/j.molcel.2011.03.002
Source
Cenik et al., Phosphate and R2D2 Restrict the Substrate Specificity of Dicer-2, an ATP-Driven Ribonuclease, Molecular Cell (2011), doi:10.1016/j.molcel.2011.03.002
Journal/Book/Conference Title
Molecular cell
Related Resources
PubMed ID
21419681
Repository Citation
Cenik ES, Fukunaga R, Lu G, Dutcher R, Wang Y, Hall TM, Zamore PD. (2011). Phosphate and R2D2 Restrict the Substrate Specificity of Dicer-2, an ATP-Driven Ribonuclease. Biochemistry and Molecular Pharmacology Publications. https://doi.org/10.1016/j.molcel.2011.03.002. Retrieved from https://escholarship.umassmed.edu/bmp_pp/130
Comments
Co-author Elif Sarinay Cenik is a student in the Biochemistry & Molecular Pharmacology program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.