The Slicer Activity of ARGONAUTE1 Is Required Specifically for the Phasing, Not Production, of Trans-Acting Short Interfering RNAs in Arabidopsis
ARGONAUTE1 (AGO1) mediates posttranscriptional silencing by microRNAs (miRNAs) and short interfering RNAS (siRNAs). AGO1-catalyzed RNA cleavage (slicing) represses miRNA targets, but current models also highlight the roles of slicing in formation of siRNAs and siRNA-AGO1 complexes. miRNA-guided slic...
| Autores: | , , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/378647 |
| Acceso en línea: | http://hdl.handle.net/10261/378647 https://api.elsevier.com/content/abstract/scopus_id/84982955531 |
| Access Level: | acceso abierto |
| Palabra clave: | ARGONAUTE1 Interfering RNAs Slicer Activity Arabidopsis Standardized |
| Sumario: | ARGONAUTE1 (AGO1) mediates posttranscriptional silencing by microRNAs (miRNAs) and short interfering RNAS (siRNAs). AGO1-catalyzed RNA cleavage (slicing) represses miRNA targets, but current models also highlight the roles of slicing in formation of siRNAs and siRNA-AGO1 complexes. miRNA-guided slicing is required for biogenesis of phased, trans-acting siRNAs (tasiRNAs), whose cleaved precursor fragments are converted to double-stranded RNA by RNA-dependent RNA polymerase 6 (RDR6). In addition, unwinding of duplex siRNA bound to AGO1 requires passenger strand cleavage in vitro. In this study, we analyze how mutation of four metal ion-coordinating residues of Arabidopsis thaliana AGO1 affects slicer activity in vitro and siRNA function in vivo. We show that while all four residues are required for slicer activity, they do not contribute equally to catalysis. Moreover, passenger strand cleavage is required for assembly of active AGO1-siRNA complexes in vivo, and many AGO1-bound siRNAs are trimmed in the absence |
|---|