Biogenesis of mammalian microRNAs by a non-canonical processing pathway.
Nucleic Acids Res
; 40(10): 4626-40, 2012 May.
Article
em En
| MEDLINE
| ID: mdl-22270084
ABSTRACT
Canonical microRNA biogenesis requires the Microprocessor components, Drosha and DGCR8, to generate precursor-miRNA, and Dicer to form mature miRNA. The Microprocessor is not required for processing of some miRNAs, including mirtrons, in which spliceosome-excised introns are direct Dicer substrates. In this study, we examine the processing of putative human mirtrons and demonstrate that although some are splicing-dependent, as expected, the predicted mirtrons, miR-1225 and miR-1228, are produced in the absence of splicing. Remarkably, knockout cell lines and knockdown experiments demonstrated that biogenesis of these splicing-independent mirtron-like miRNAs, termed 'simtrons', does not require the canonical miRNA biogenesis components, DGCR8, Dicer, Exportin-5 or Argonaute 2. However, simtron biogenesis was reduced by expression of a dominant negative form of Drosha. Simtrons are bound by Drosha and processed in vitro in a Drosha-dependent manner. Both simtrons and mirtrons function in silencing of target transcripts and are found in the RISC complex as demonstrated by their interaction with Argonaute proteins. These findings reveal a non-canonical miRNA biogenesis pathway that can produce functional regulatory RNAs.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Processamento Pós-Transcricional do RNA
/
MicroRNAs
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Nucleic Acids Res
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos