title: Plant dicistronic tRNA-snoRNA genes: a new mode of expression of the small nucleolar RNAs processed by RNase Z.
abstract: Small nucleolar RNAs (snoRNAs) guiding modifications of ribosomal RNAs and other RNAs display diverse modes of gene organization and expression depending on the eukaryotic system: in animals most are intron encoded, in yeast many are monocistronic genes and in plants most are polycistronic (independent or intronic) genes. Here we report an unprecedented organization: plant dicistronic tRNA-snoRNA genes. In Arabidopsis thaliana we identified a gene family encoding 12 novel box C/D snoRNAs (snoR43) located just downstream from tRNA(Gly) genes. We confirmed that they are transcribed, probably from the tRNA gene promoter, producing dicistronic tRNA(Gly)-snoR43 precursors. Using transgenic lines expressing a tagged tRNA-snoR43.1 gene we show that the dicistronic precursor is accurately processed to both snoR43.1 and tRNA(Gly). In addition, we show that a recombinant RNase Z, the plant tRNA 3' processing enzyme, efficiently cleaves the dicistronic precursor in vitro releasing the snoR43.1 from the tRNA(Gly). Finally, we describe a similar case in rice implicating a tRNA(Met-e) expressed in fusion with a novel C/D snoRNA, showing that this mode of snoRNA expression is found in distant plant species.
authors.affiliation: Laboratoire Génome et Développement des Plantes, UMR CNRS 5096, Université de Perpignan, 66860 Perpignan cedex, France.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kruszka
authors.forename: Fredy
authors.initials: F
authors.lastname: Barneche
authors.forename: Romain
authors.initials: R
authors.lastname: Guyot
authors.forename: Jérôme
authors.initials: J
authors.lastname: Ailhas
authors.forename: Isabelle
authors.initials: I
authors.lastname: Meneau
authors.forename: Steffen
authors.initials: S
authors.lastname: Schiffer
authors.forename: Anita
authors.initials: A
authors.lastname: Marchfelder
authors.forename: Manuel
authors.initials: M
authors.lastname: Echeverría
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000235:genetics*; D001483:Base Sequence; D004722:Endoribonucleases / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D009690:Nucleic Acid Conformation; D012275:Oryza / Q000235:genetics; D030821:Plants, Genetically Modified; D020537:RNA, Small Nucleolar / Q000235:genetics*; D012343:RNA, Transfer / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D020537:RNA, Small Nucleolar; D012343:RNA, Transfer; D004722:Endoribonucleases; C110250:RNase Z