The first step in microRNA (miRNA) biogenesis occurs in the nucleus and is mediated by the Microprocessor complex containing the RNase III-like enzyme Drosha and its cofactor DGCR8. Here we show that the 5'-->3' exonuclease Xrn2 associates with independently transcribed miRNAs and, in combination with Drosha processing, attenuates transcription in downstream regions. We suggest that, after Drosha cleavage, a torpedo-like mechanism acts on nascent long precursor miRNAs, whereby Xrn2 exonuclease degrades the RNA polymerase II-associated transcripts inducing its release from the template. While involved in primary transcript termination, this attenuation effect does not restrict clustered miRNA expression, which, in the majority of cases, is separated by short spacers. We also show that transcripts originating from a miRNA promoter are retained on the chromatin template and are more efficiently processed than those produced from mRNA or snRNA Pol II-dependent promoters. These data imply that coupling between transcription and processing promotes efficient expression of independently transcribed miRNAs.

Coupled RNA processing and transcription of intergenic primary miRNAs. (2009) / Ballarino, Monica; Pagano, Francesca; Girardi, Erika; Cacchiarelli, Davide; Morlando, Mariangela; Bozzoni, Irene; Pagano, Francesca. - In: MOLECULAR AND CELLULAR BIOLOGY. - ISSN 0270-7306. - STAMPA. - 29:(2009), pp. 5632-5638. [10.1128/MCB.00664-09]

Coupled RNA processing and transcription of intergenic primary miRNAs. (2009)

BALLARINO, MONICA;PAGANO, FRANCESCA;GIRARDI, ERIKA;CACCHIARELLI, DAVIDE;MORLANDO, MARIANGELA;BOZZONI, Irene;PAGANO, FRANCESCA
2009

Abstract

The first step in microRNA (miRNA) biogenesis occurs in the nucleus and is mediated by the Microprocessor complex containing the RNase III-like enzyme Drosha and its cofactor DGCR8. Here we show that the 5'-->3' exonuclease Xrn2 associates with independently transcribed miRNAs and, in combination with Drosha processing, attenuates transcription in downstream regions. We suggest that, after Drosha cleavage, a torpedo-like mechanism acts on nascent long precursor miRNAs, whereby Xrn2 exonuclease degrades the RNA polymerase II-associated transcripts inducing its release from the template. While involved in primary transcript termination, this attenuation effect does not restrict clustered miRNA expression, which, in the majority of cases, is separated by short spacers. We also show that transcripts originating from a miRNA promoter are retained on the chromatin template and are more efficiently processed than those produced from mRNA or snRNA Pol II-dependent promoters. These data imply that coupling between transcription and processing promotes efficient expression of independently transcribed miRNAs.
2009
01 Pubblicazione su rivista::01a Articolo in rivista
Coupled RNA processing and transcription of intergenic primary miRNAs. (2009) / Ballarino, Monica; Pagano, Francesca; Girardi, Erika; Cacchiarelli, Davide; Morlando, Mariangela; Bozzoni, Irene; Pagano, Francesca. - In: MOLECULAR AND CELLULAR BIOLOGY. - ISSN 0270-7306. - STAMPA. - 29:(2009), pp. 5632-5638. [10.1128/MCB.00664-09]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/16799
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