title: G-quadruplex formation by human telomeric repeats-containing RNA in Na+ solution.
abstract: For a long time, telomeres have been considered to be transcriptionally silent. Very recently, a breaking finding from two groups demonstrated that telomere DNA is transcribed into telomeric repeat-containing RNA in mammalian cells (Azzalin, C. M.; Reichenbach, P.; Khoriauli, L.; Giulotto, E.; Lingner, J. Science 2007, 318, 798-801. Schoefter, S.; Blasco, M. A. Nat. Cell Biol. 2008, 10, 228-236). The telomeric RNA, a newly appeared player in telomere biology, may be a key component of telomere machinery. In the current study, we used a combination of NMR, circular dichroism (CD), matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOFMS), and gel electrophoresis to investigate the structural features of a human telomere RNA sequence. We demonstrated that human telomere RNA can form a parallel G-quadruplex structure in the presence of Na(+). Importantly, we found for the first time that the G-quadruplex forming telomere RNA protects itself from enzymatic digestion. These results provide valuable information to allow understanding of the structure and function of human telomeric RNA.
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan. xuyan@mkomi.rcast.u-tokyo.ac.jp
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.forename: Kuniyuki
authors.initials: K
authors.lastname: Kaminaga
authors.forename: Makoto
authors.initials: M
authors.lastname: Komiyama
mesh_terms: D001483:Base Sequence; D002942:Circular Dichroism / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D054856:G-Quadruplexes; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D012313:RNA / Q000138:chemical synthesis / Q000737:chemistry*; D012015:Reference Standards; D012964:Sodium / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D016615:Telomere / Q000737:chemistry*
chemical_list: D012996:Solutions; D012313:RNA; D012964:Sodium