To date microRNA precursors have been described as long capped and polyadenilated transcripts, mostly transcribed by RNA polymerase II. The 21 nucleotides miRNAs are generated by a nucleo-cytoplasmic processing cascade. The nuclear processing machinery is composed of two key factors, the RNAse III Drosha and its partner DGCR8. Using the ChIP assay we demonstrate the co-transcriptional recruitment of Drosha protein to miRNA genomic loci. We show that this interaction requires structural determinants in the RNA substrate. Moreover, a canonical RNA-pol II cleavage and polyadenilation site downstream to miRNAs interferes with Drosha processing, suggesting a competition between these two events. Since Drosha association on pri-miRNA occurs co-transcriptionally and its processing defines pre-miRNA 3’-end, we tested the effects of Drosha activity on transcription. We find that a co-transcriptional cleavage leads to negative effects on elongation suggesting a possible interplay between transcription and processing in vivo. Taken together our data suggest a “miRNA-factory” model that ensures a correct and efficient production of the physiological miRNA precursors.
Scheda prodotto non validato
Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo
|Titolo:||The RNAseIII drosha controls miRNA biogenesis during transcription|
|Data di pubblicazione:||2007|
|Appare nella tipologia:||04a Atto di comunicazione a congresso|