title: A human microRNA precursor binding to folic acid discovered by small RNA transcriptomic SELEX.
abstract: RNA aptamers are structured motifs that bind to specific molecules. A growing number of RNAs bearing aptamer elements, whose functions are modulated by direct binding of metabolites, have been found in living cells. Recent studies have suggested that more small RNAs binding to metabolites likely exist and may be involved in diverse cellular processes. However, conventional methods are not necessarily suitable for the discovery of such RNA aptamer elements in small RNAs with lengths ranging from 50 to 200 nucleotides, due to the far more abundant tRNAs in this size range. Here, we describe a new in vitro selection method to uncover naturally occurring small RNAs capable of binding to a ligand of interest, referred to as small RNA transcriptomic SELEX (smaRt-SELEX). By means of this method, we identified a motif in human precursor microRNA 125a (hsa-pre-miR-125a) that interacts with folic acid. Mutation studies revealed that the terminal loop region of hsa-pre-miR-125a is important for this binding interaction. This method has potential for the discovery of new RNA aptamer elements or catalytic motifs in biological small RNA fractions.
authors.affiliation: Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Terasaka
authors.affiliation: Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Futai
authors.affiliation: Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Katoh
authors.affiliation: Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.|JST, CREST, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suga
mesh_terms: D005492:Folic Acid / Q000378:metabolism*; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D052156:SELEX Aptamer Technique; D059467:Transcriptome
chemical_list: D035683:MicroRNAs; D005492:Folic Acid
keywords: SELEX; folic acid; microRNA; ribozyme; small RNA