title: Coupling between snoRNP assembly and 3' processing controls box C/D snoRNA biosynthesis in yeast.
abstract: RNA polymerase II transcribes genes encoding proteins and a large number of small stable RNAs. While pre-mRNA 3'-end formation requires a machinery ensuring tight coupling between cleavage and polyadenylation, small RNAs utilize polyadenylation-independent pathways. In yeast, specific factors required for snRNA and snoRNA 3'-end formation were characterized as components of the APT complex that is associated with the core complex of the cleavage/polyadenylation machinery (core-CPF). Other essential factors were identified as independent components: Nrd1p, Nab3p and Sen1p. Here we report that mutations in the conserved box D of snoRNAs and in the snoRNP-specific factor Nop1p interfere with transcription and 3'-end formation of box C/D snoRNAs. We demonstrate that Nop1p is associated with box C/D snoRNA genes and that it interacts with APT components. These data suggest a mechanism of quality control in which efficient transcription and 3'-end formation occur only when nascent snoRNAs are successfully assembled into functional particles.
authors.affiliation: Department of Genetics and Molecular Biology, Institute Pasteur Cenci-Bolognetti, University of Rome La Sapienza, Rome, Italy.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Morlando
authors.forename: Monica
authors.initials: M
authors.lastname: Ballarino
authors.forename: Paolo
authors.initials: P
authors.lastname: Greco
authors.forename: Elisa
authors.initials: E
authors.lastname: Caffarelli
authors.forename: Bernhard
authors.initials: B
authors.lastname: Dichtl
authors.forename: Irene
authors.initials: I
authors.lastname: Bozzoni
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D009154:Mutation; D010957:Plasmids; D020718:Ribonucleoproteins, Small Nucleolar / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D020718:Ribonucleoproteins, Small Nucleolar