title: RNA polymerase III regulates cytosolic RNA:DNA hybrids and intracellular microRNA expression.
abstract: RNA:DNA hybrids form in the nuclei and mitochondria of cells as transcription-induced R-loops or G-quadruplexes, but exist only in the cytosol of virus-infected cells. Little is known about the existence of RNA:DNA hybrids in the cytosol of virus-free cells, in particular cancer or transformed cells. Here, we show that cytosolic RNA:DNA hybrids are present in various human cell lines, including transformed cells. Inhibition of RNA polymerase III (Pol III), but not DNA polymerase, abrogated cytosolic RNA:DNA hybrids. Cytosolic RNA:DNA hybrids bind to several components of the microRNA (miRNA) machinery-related proteins, including AGO2 and DDX17. Furthermore, we identified miRNAs that are specifically regulated by Pol III, providing a potential link between RNA:DNA hybrids and the miRNA machinery. One of the target genes, exportin-1, is shown to regulate cytosolic RNA:DNA hybrids. Taken together, we reveal previously unknown mechanism by which Pol III regulates the presence of cytosolic RNA:DNA hybrids and miRNA biogenesis in various human cells.
authors.affiliation: From the Immunology Programme and Department of Microbiology, Centre for Life Sciences, and the NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456, the Laboratory of Adjuvant Innovation and.
authors.forename: Christine Xing'er
authors.initials: CX
authors.lastname: Koo
authors.affiliation: the Laboratory of Adjuvant Innovation and the Laboratory of Vaccine Science, World Premier International Immunology Frontier Research Center (iFREC), Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Kobiyama
authors.affiliation: From the Immunology Programme and Department of Microbiology, Centre for Life Sciences, and the NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456.
authors.forename: Yu J
authors.initials: YJ
authors.lastname: Shen
authors.affiliation: From the Immunology Programme and Department of Microbiology, Centre for Life Sciences, and.
authors.forename: Nina
authors.initials: N
authors.lastname: LeBert
authors.affiliation: the Laboratory of Bioinformatics, National Institute of Biomedical Innovation (NIBIO), Ibaraki, Osaka 567-0085, Japan, and.
authors.forename: Shandar
authors.initials: S
authors.lastname: Ahmad
authors.affiliation: From the Immunology Programme and Department of Microbiology, Centre for Life Sciences, and.
authors.forename: Muznah
authors.initials: M
authors.lastname: Khatoo
authors.affiliation: the Laboratory of Adjuvant Innovation and the Laboratory of Vaccine Science, World Premier International Immunology Frontier Research Center (iFREC), Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Taiki
authors.initials: T
authors.lastname: Aoshi
authors.affiliation: From the Immunology Programme and Department of Microbiology, Centre for Life Sciences, and the NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456, stephan_gasser@nuhs.edu.sg.
authors.forename: Stephan
authors.initials: S
authors.lastname: Gasser
authors.affiliation: the Laboratory of Adjuvant Innovation and the Laboratory of Vaccine Science, World Premier International Immunology Frontier Research Center (iFREC), Osaka University, Suita, Osaka 565-0871, Japan kenishii@biken.osaka-u.ac.jp.
authors.forename: Ken J
authors.initials: KJ
authors.lastname: Ishii
mesh_terms: D001483:Base Sequence; D045744:Cell Line, Tumor; D003600:Cytosol / Q000378:metabolism; D004247:DNA / Q000235:genetics*; D004249:DNA Damage; D006801:Humans; D013058:Mass Spectrometry; D035683:MicroRNAs / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D012313:RNA / Q000235:genetics*; D012320:RNA Polymerase III / Q000378:metabolism*; D034741:RNA, Small Interfering
chemical_list: D035683:MicroRNAs; D034741:RNA, Small Interfering; D012313:RNA; D004247:DNA; D012320:RNA Polymerase III
keywords: Antibody S9.6; Cancer; DNA Damage; Innate Immunity; MicroRNA (miRNA); RNA Polymerase III; RNA Transport; RNA:DNA Hybrid; RNase H