title: Mammalian 5'-capped microRNA precursors that generate a single microRNA.
abstract: MicroRNAs (miRNAs) are short RNA gene regulators typically produced from primary transcripts that are cleaved by the nuclear microprocessor complex, with the resulting precursor miRNA hairpins exported by exportin 5 and processed by cytoplasmic Dicer to yield two (5p and 3p) miRNAs. Here, we document microprocessor-independent 7-methylguanosine (m(7)G)-capped pre-miRNAs, whose 5' ends coincide with transcription start sites and 3' ends are most likely generated by transcription termination. By establishing a small RNA Cap-seq method that employs the cap-binding protein eIF4E, we identified a group of murine m(7)G-capped pre-miRNAs genome wide. The m(7)G-capped pre-miRNAs are exported via the PHAX-exportin 1 pathway. After Dicer cleavage, only the 3p-miRNA is efficiently loaded onto Argonaute to form a functional microRNP. This unusual miRNA biogenesis pathway, which differs in pre-miRNA synthesis, nuclear-cytoplasmic transport, and guide strand selection, enables the development of shRNA expression constructs that produce a single 3p-siRNA.
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Boyer Center for Molecular Medicine, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA.
authors.forename: Mingyi
authors.initials: M
authors.lastname: Xie
authors.affiliation: Department of Neurobiology, Kavli Institute of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.
authors.forename: Mingfeng
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Boyer Center for Molecular Medicine, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Vilborg
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Boyer Center for Molecular Medicine, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA.
authors.forename: Nara
authors.initials: N
authors.lastname: Lee
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Boyer Center for Molecular Medicine, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA.
authors.forename: Mei-Di
authors.initials: MD
authors.lastname: Shu
authors.affiliation: Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.
authors.forename: Valeria
authors.initials: V
authors.lastname: Yartseva
authors.affiliation: Department of Neurobiology, Kavli Institute of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.
authors.forename: Nenad
authors.initials: N
authors.lastname: Šestan
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Boyer Center for Molecular Medicine, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA. Electronic address: joan.steitz@yale.edu.
authors.forename: Joan A
authors.initials: JA
authors.lastname: Steitz
mesh_terms: D000818:Animals; D060565:Argonaute Proteins / Q000378:metabolism; D001483:Base Sequence; D053898:Biosynthetic Pathways; D053487:DEAD-box RNA Helicases / Q000378:metabolism; D055106:Genome-Wide Association Study; D006151:Guanosine / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D028884:Karyopherins / Q000378:metabolism; D051379:Mice; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D012315:RNA Caps; D012319:RNA Polymerase II / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D043244:Ribonuclease III / Q000378:metabolism; D061806:Transcription Termination, Genetic; D000097606:Exportin 1 Protein
chemical_list: D060565:Argonaute Proteins; D053487:DEAD-box RNA Helicases; D006151:Guanosine; D028884:Karyopherins; D035683:MicroRNAs; D012315:RNA Caps; D012319:RNA Polymerase II; D034741:RNA, Small Interfering; D018160:Receptors, Cytoplasmic and Nuclear; D043244:Ribonuclease III; D000097606:Exportin 1 Protein; C116616:8-methylguanosine; C572916:MIRN320 microRNA, human; C408087:DICER1 protein, human