Intertwined pathways for Argonaute-mediated microRNA biogenesis in Drosophila Journal Article
| Authors: | Yang, J. S.; Smibert, P.; Westholm, J. O.; Jee, D.; Maurin, T.; Lai, E. C. |
| Article Title: | Intertwined pathways for Argonaute-mediated microRNA biogenesis in Drosophila |
| Abstract: | Although Dicer is essential for general microRNA (miRNA) biogenesis, vertebrate mir-451 is Dicer independent. Instead, its short pre-miRNA hairpin is 'sliced' by Ago2, then 3′-resected into mature miRNAs. Here, we show that Drosophila cells and animals generate functional small RNAs from mir-451-type precursors. However, their bulk maturation arrests as Ago-cleaved pre-miRNAs, which mostly associate with the RNAi effector AGO2. Routing of pre-mir-451 hairpins to the miRNA effector AGO1 was inhibited by Dicer-1 and its partner Loqs. Loss of these miRNA factors promoted association of pre-mir-451 with AGO1, which sliced them and permitted maturation into ∼23-26 nt products. The difference was due to the 3′ modification of single-stranded species in AGO2 by Hen1 methyltransferase, whose depletion permitted 3′ trimming of Ago-cleaved pre-miRNAs in AGO2. Surprisingly, Nibbler, a 3′-5′ exoribonuclease that trims 'long' mature miRNAs in AGO1, antagonized miR-451 processing. We used an in vitro reconstitution assay to identify a soluble, EDTA-sensitive activity that resects sliced pre-miRNAs in AGO1 complexes. Finally, we use deep sequencing to show that depletion of dicer-1 increases the diversity of small RNAs in AGO1, including some candidate mir-451-like loci. Altogether, we document unexpected aspects of miRNA biogenesis and Ago sorting, and provide insights into maturation of Argonaute-cleaved miRNA substrates. © 2013 The Author(s) 2013. Published by Oxford University Press. |
| Keywords: | controlled study; unclassified drug; nonhuman; animal cell; animals; animal tissue; cells, cultured; microrna; protein depletion; protein targeting; rna, small interfering; drosophila; rna interference; in vitro study; rna-binding proteins; methyltransferase; methyltransferases; rna synthesis; micrornas; rna processing; argonaute protein; drosophila proteins; rna helicases; rna cleavage; rna precursors; argonaute 1 protein; protein modification; dicer; ribonuclease iii; rna processing, post-transcriptional; argonaute 2 protein; microrna 451; edetic acid; argonaute proteins; exoribonuclease; exoribonucleases; priority journal; article; hen1 methyltransferase |
| Journal Title: | Nucleic Acids Research |
| Volume: | 42 |
| Issue: | 3 |
| ISSN: | 0305-1048 |
| Publisher: | Oxford University Press |
| Date Published: | 2014-02-01 |
| Start Page: | 1987 |
| End Page: | 2002 |
| Language: | English |
| DOI: | 10.1093/nar/gkt1038 |
| PROVIDER: | scopus |
| PMCID: | PMC3919586 |
| PUBMED: | 24220090 |
| DOI/URL: | |
| Notes: | Export Date: 2 April 2014 -- CODEN: NARHA -- Source: Scopus |
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