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.

• PMID: 15167896
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Reference Type

Journal Article | Research Support, Non-U.S. Gov't

Authors

Morlando M, Ballarino M, Greco P, Caffarelli E, Dichtl B, Bozzoni I

Primary Lit For

NOP1 | NAB3 | DNA-directed RNA polymerase II complex | Box C/D snoRNP complex

Additional Lit For

SNR13 | NRD1 | SNR50 | SEN1 | SNR71

Review For