title: Assembly into snoRNP controls 5'-end maturation of a box C/D snoRNA in Saccharomyces cerevisiae.
abstract: The SNR52 gene, coding for a box C/D snoRNA, is the only snoRNA gene transcribed by RNA polymerase (Pol) III in Saccharomyces cerevisiae. Pol III transcription generates a precisely terminated primary transcript that undergoes extensive 5'-end processing. Here, we show that mutations of the box C/D core motif required for snoRNP assembly compromise 5'-end maturation of the SNR52 snoRNA. Upstream processing was also impaired by specific depletion of either Nop1p or Nop58p snoRNP proteins. We further show that the nuclear exosome is required for 3'-end maturation of SNR52 snoRNA, at variance with all the other known Pol III transcripts. Our data suggest a functional coupling between snoRNP assembly and 5'-end maturation of independently transcribed box C/D snoRNAs.
authors.affiliation: Dipartimento di Biochimica e Biologia Molecolare, Università degli Studi di Parma, 43100 Parma, Italy.
authors.forename: Milena
authors.initials: M
authors.lastname: Preti
authors.forename: Elisa
authors.initials: E
authors.lastname: Guffanti
authors.forename: Eleonora
authors.initials: E
authors.lastname: Valitutto
authors.forename: Giorgio
authors.initials: G
authors.lastname: Dieci
mesh_terms: D024509:3' Flanking Region; D024506:5' Flanking Region; D001483:Base Sequence; D002466:Cell Nucleolus / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D012320:RNA Polymerase III / Q000235:genetics / Q000378:metabolism; D020537:RNA, Small Nucleolar / Q000235:genetics* / Q000378:metabolism; D020718:Ribonucleoproteins, Small Nucleolar / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: C064793:NOP1 protein, S cerevisiae; C438199:NOP58 protein, S cerevisiae; D009687:Nuclear Proteins; D020537:RNA, Small Nucleolar; D020718:Ribonucleoproteins, Small Nucleolar; D029701:Saccharomyces cerevisiae Proteins; D012320:RNA Polymerase III