title: Argonaute-associated short introns are a novel class of gene regulators.
abstract: MicroRNAs (miRNAs) are short (∼22 nucleotides) regulators of gene expression acting by direct base pairing to 3'-UTR target sites in messenger RNAs. Mature miRNAs are produced by two sequential endonucleolytic cleavages facilitated by Drosha in the nucleus and Dicer in the cytoplasm. A subclass of miRNAs, termed mirtrons, derives from short introns and enters the miRNA biogenesis pathway as Dicer substrates. Here we uncover a third biogenesis strategy that, similar to mirtron biogenesis, initiates from short introns but bypasses Dicer cleavage. These short introns (80-100 nucleotides), coined agotrons, are associated with and stabilized by Argonaute (Ago) proteins in the cytoplasm. Some agotrons are completely conserved in mammalian species, suggesting that they are functionally important. Furthermore, we demonstrate that the agotrons are capable of repressing mRNAs with seed-matching target sequences in the 3'-UTR. These data provide evidence for a novel RNA regulator of gene expression, which bypasses the canonical miRNA biogenesis machinery.
authors.affiliation: Department of Molecular Biology and Genetics (MBG), Interdisciplinary Nanoscience Center (iNANO), Aarhus University, C.F. Moellers Alle 3, Build 1130, Aarhus 8000, Denmark.
authors.forename: Thomas B
authors.identifier: 0000-0002-7573-9657
authors.initials: TB
authors.lastname: Hansen
authors.affiliation: Department of Molecular Biology and Genetics (MBG), Interdisciplinary Nanoscience Center (iNANO), Aarhus University, C.F. Moellers Alle 3, Build 1130, Aarhus 8000, Denmark.
authors.forename: Morten T
authors.initials: MT
authors.lastname: Venø
authors.affiliation: Department of Molecular Biology and Genetics (MBG), Interdisciplinary Nanoscience Center (iNANO), Aarhus University, C.F. Moellers Alle 3, Build 1130, Aarhus 8000, Denmark.
authors.forename: Trine I
authors.initials: TI
authors.lastname: Jensen
authors.affiliation: Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, New York 10029, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Schaefer
authors.affiliation: Department of Molecular Biology and Genetics (MBG), Interdisciplinary Nanoscience Center (iNANO), Aarhus University, C.F. Moellers Alle 3, Build 1130, Aarhus 8000, Denmark.
authors.forename: Christian K
authors.initials: CK
authors.lastname: Damgaard
authors.affiliation: Department of Molecular Biology and Genetics (MBG), Interdisciplinary Nanoscience Center (iNANO), Aarhus University, C.F. Moellers Alle 3, Build 1130, Aarhus 8000, Denmark.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Kjems
mesh_terms: D000818:Animals; D060565:Argonaute Proteins / Q000235:genetics*; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D047468:Immunoprecipitation / Q000379:methods; D007438:Introns / Q000235:genetics*; D051379:Mice; D035683:MicroRNAs / Q000235:genetics*; D012326:RNA Splicing / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism; D017423:Sequence Analysis, RNA; D050396:TRPP Cation Channels / Q000235:genetics
chemical_list: D060565:Argonaute Proteins; D053487:DEAD-box RNA Helicases; D035683:MicroRNAs; D012333:RNA, Messenger; D043244:Ribonuclease III; D050396:TRPP Cation Channels; C466422:AGO2 protein, human; C526735:Ago2 protein, mouse; C408087:DICER1 protein, human