title: Expanding the action of duplex RNAs into the nucleus: redirecting alternative splicing.
abstract: Double-stranded RNAs are powerful agents for silencing gene expression in the cytoplasm of mammalian cells. The potential for duplex RNAs to control expression in the nucleus has received less attention. Here, we investigate the ability of small RNAs to redirect splicing. We identify RNAs targeting an aberrant splice site that restore splicing and production of functional protein. RNAs can target sequences within exons or introns and affect the inclusion of exons within SMN2 and dystrophin, genes responsible for spinal muscular atrophy and Duchenne muscular dystrophy, respectively. Duplex RNAs recruit argonaute 2 (AGO2) to pre-mRNA transcripts and altered splicing requires AGO2 expression. AGO2 promotes transcript cleavage in the cytoplasm, but recruitment of AGO2 to pre-mRNAs does not reduce transcript levels, exposing a difference between cytoplasmic and nuclear pathways. Involvement of AGO2 in splicing, a classical nuclear process, reinforces the conclusion from studies of RNA-mediated transcriptional silencing that RNAi pathways can be adapted to function in the mammalian nucleus. These data provide a new strategy for controlling splicing and expand the reach of small RNAs within the nucleus of mammalian cells.
authors.affiliation: Department of Pharmacology, UT Southwestern Medical Center at Dallas, Dallas, TX 75390-9041, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Jiaxin
authors.initials: J
authors.lastname: Hu
authors.forename: David R
authors.initials: DR
authors.lastname: Corey
mesh_terms: D017398:Alternative Splicing; D060565:Argonaute Proteins / Q000502:physiology; D020137:Base Pair Mismatch; D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism; D016189:Dystrophin / Q000235:genetics; D005091:Exons; D006367:HeLa Cells; D006801:Humans; D012322:RNA Precursors / Q000378:metabolism; D012330:RNA, Double-Stranded / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D058727:RNA, Small Untranslated / Q000737:chemistry / Q000378:metabolism*; D055533:Survival of Motor Neuron 1 Protein / Q000235:genetics
chemical_list: C466422:AGO2 protein, human; D060565:Argonaute Proteins; D002843:Chromatin; D016189:Dystrophin; D012322:RNA Precursors; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D058727:RNA, Small Untranslated; C526471:SMN1 protein, human; D055533:Survival of Motor Neuron 1 Protein