): RNA interference (RNAi) is the surprising ability of double-stranded RNA (dsRNA) when introduced into an animal to direct the specific degradation of a corresponding mRNA. In the last two years, RNAi has been identified in many animals, including flies, worms, and mice, and has provided a new tool for studying gene function and for functional genomics. Evidence is mounting that the cellular function of RNAi is to maintain the integrity of the genome by suppressing transposon """"""""jumping."""""""" The RNAi machinery may also serve to defend cells against viral infection and perhaps even to regulate gene expression in the germ line. To begin to understand the mechanism underlying RNAi, we recently developed a cell-free system from Drosophila embryos that recapitulates many of the features of RNAi. Using this in vitro system, we have begun a molecular analysis of RNAi. In this proposal, our specific goals are (1) to understand how the sequence of the dsRNA determines the sites of cleavage on the target mRNA; (2) to discover the enzymatic mechanism by which the dsRNA is processed to create """"""""guide RNAs"""""""" that direct cleavage of the target mRNA; (3) to determine the role of ATP in the RNAi pathway; and (4) to identify the proteins that compose the RNAi machinery. These studies promise to help us better understand the mechanism by which the RNAi machinery recognizes and processes dsRNA and then uses the information in the dsRNA to target a specific mRNA for destruction. Our experiments may also help to decipher the rules for selecting potent dsRNAs for silencing specific gene expression and in designing collections of dsRNAs for functional genomic studies. Finally, since a detailed understanding of RNAi is a prerequisite for developing dsRNA analogs that induce RNAi in mammals but do not provoke non-specific anti-viral responses, our work may ultimately speed the development of dsRNA-based therapies for human diseases.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
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Cell Development and Function Integrated Review Group (CDF)
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Rhoades, Marcus M
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University of Massachusetts Medical School Worcester
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Lewis, Samuel H; Quarles, Kaycee A; Yang, Yujing et al. (2018) Pan-arthropod analysis reveals somatic piRNAs as an ancestral defence against transposable elements. Nat Ecol Evol 2:174-181
Ge, Daniel Tianfang; Tipping, Cindy; Brodsky, Michael H et al. (2016) Rapid Screening for CRISPR-Directed Editing of the Drosophila Genome Using white Coconversion. G3 (Bethesda) 6:3197-3206
Chou, Min-Te; Han, Bo W; Hsiao, Chiung-Po et al. (2015) Tailor: a computational framework for detecting non-templated tailing of small silencing RNAs. Nucleic Acids Res 43:e109
Han, Bo W; Wang, Wei; Zamore, Phillip D et al. (2015) piPipes: a set of pipelines for piRNA and transposon analysis via small RNA-seq, RNA-seq, degradome- and CAGE-seq, ChIP-seq and genomic DNA sequencing. Bioinformatics 31:593-5
Wang, Wei; Han, Bo W; Tipping, Cindy et al. (2015) Slicing and Binding by Ago3 or Aub Trigger Piwi-Bound piRNA Production by Distinct Mechanisms. Mol Cell 59:819-30
Salomon, William E; Jolly, Samson M; Moore, Melissa J et al. (2015) Single-Molecule Imaging Reveals that Argonaute Reshapes the Binding Properties of Its Nucleic Acid Guides. Cell 162:84-95
Han, Bo W; Wang, Wei; Li, Chengjian et al. (2015) Noncoding RNA. piRNA-guided transposon cleavage initiates Zucchini-dependent, phased piRNA production. Science 348:817-21
Roy, Christian K; Olson, Sara; Graveley, Brenton R et al. (2015) Assessing long-distance RNA sequence connectivity via RNA-templated DNA-DNA ligation. Elife 4:
Fukunaga, Ryuya; Colpan, Cansu; Han, Bo W et al. (2014) Inorganic phosphate blocks binding of pre-miRNA to Dicer-2 via its PAZ domain. EMBO J 33:371-84
Zhang, Zhao; Wang, Jie; Schultz, Nadine et al. (2014) The HP1 homolog rhino anchors a nuclear complex that suppresses piRNA precursor splicing. Cell 157:1353-63

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