Micro-RNAs (miRNA) are an abundant class of 22-nucleotide regulatory elements that guide the silencing of mammalian genes and contribute to broad range of cellular processes including developmental timing, life span, brain development, cell proliferation, and cancer. A critical step in the miRNA pathway is the assembly of miRNAs into an active form, a large ribonucleoprotein complex called RISC. This project aims to characterize the assembly of RISC with an emphasis on understanding the structural details underlying processing and loading of miRNAs into RISC. Research is focused on a three-protein assembly termed the RISC-loading complex (RLC). Using a combination of biochemistry and structural biology we will identify key features of the RLC mechanism that may be exploited for therapeutic purposes. Biochemical efforts will focus on dissecting the mechanisms underlying miRNA recognition and processing efficiency. Electron microscopy will be used to determine the molecular architecture of the RLC, which will guide further biochemical experiments.
We aim to determine molecular structures of the RLC stalled at key steps in RISC-loading to fully visualize this essential cellular process. These combined structural and functional studies will provide comprehensive mechanistic insights into one of the most fundamental but least understood pathways of controlling mammalian gene expression. Project Narrative RNA interference (RNAi) is a natural process by which human genes are turned off, or "silenced", which is involved in biological functions ranging from life span, to brain development, to cancer. This project aims to understand the molecular machinery that decides which genes will be silenced by RNAi. Results will contribute to on-going efforts to harness the RNAi process as a powerful new type of therapeutic for the treatment of human disease.
|Horman, Shane R; Janas, Maja M; Litterst, Claudia et al. (2013) Akt-mediated phosphorylation of argonaute 2 downregulates cleavage and upregulates translational repression of MicroRNA targets. Mol Cell 50:356-67|
|De, Nabanita; Young, Lisa; Lau, Pick-Wei et al. (2013) Highly complementary target RNAs promote release of guide RNAs from human Argonaute2. Mol Cell 50:344-55|
|Pratt, Ashley J; Rambo, Robert P; Lau, Pick-Wei et al. (2012) Preparation and characterization of the extracellular domain of human Sid-1. PLoS One 7:e33607|
|Schirle, Nicole T; MacRae, Ian J (2012) The crystal structure of human Argonaute2. Science 336:1037-40|
|Lau, Pick-Wei; Potter, Clinton S; Carragher, Bridget et al. (2012) DOLORS: versatile strategy for internal labeling and domain localization in electron microscopy. Structure 20:1995-2002|
|Lau, Pick-Wei; Guiley, Keelan Z; De, Nabanita et al. (2012) The molecular architecture of human Dicer. Nat Struct Mol Biol 19:436-40|
|Bale, Shridhar; Julien, Jean-Philippe; Bornholdt, Zachary A et al. (2012) Marburg virus VP35 can both fully coat the backbone and cap the ends of dsRNA for interferon antagonism. PLoS Pathog 8:e1002916|
|Guiley, Keelan Z; Pratt, Ashley J; MacRae, Ian J (2012) Single-pot enzymatic synthesis of Dicer-substrate siRNAs. Nucleic Acids Res 40:e40|
|De, Nabanita; Macrae, Ian J (2011) Purification and assembly of human Argonaute, Dicer, and TRBP complexes. Methods Mol Biol 725:107-19|
|Hastie, Kathryn M; Kimberlin, Christopher R; Zandonatti, Michelle A et al. (2011) Structure of the Lassa virus nucleoprotein reveals a dsRNA-specific 3' to 5' exonuclease activity essential for immune suppression. Proc Natl Acad Sci U S A 108:2396-401|
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