MicroRNAs are processed by Drosha, and previous data had suggested that this occurred soon after transcription. Following Drosha recruitment and using nuclear run-on technology, data now indicate that miRNAs both within and outside of introns are processed co-transcriptionally and that exonucleases enter the fray to aid processing before splicing, implying that Drosha cleavage influences the maturation of the pre-mRNAs in which miRNAs reside.
- Mariangela Morlando
- Monica Ballarino
- Nick J Proudfoot
