In RNA-directed silencing pathways, ternary complexes result from small RNA-guided ARGONAUTE (AGO) associating with target transcripts. Target transcripts are often silenced through direct cleavage (slicing), destabilization through slicer-independent turnover mechanisms, and translational repression. Here, wild-type and active-site defective forms of several Arabidopsis thaliana AGO proteins involved in posttranscriptional silencing were...
Endogenous small interfering RNAs (siRNAs) are a class of naturally occuring regulatory RNAs found in fungi, plants, and animals. Some endogenous siRNAs are required to silence transposons or function in chromosome segregation; however, the specific roles of most endogenous siRNAs are unclear. The helicase gene eri-6/7 was identified in the...
The advent of high-throughput sequencing (HTS) methods has enabled direct approaches to quantitatively profile small RNA
populations. However, these methods have been limited by several factors, including representational artifacts and lack of
established statistical methods of analysis. Furthermore, massive HTS data sets present new problems related to data processing
and...
Transacting siRNA (tasiRNA) biogenesis in Arabidopsis is initiated
by microRNA (miRNA) –guided cleavage of primary transcripts. In
the case of TAS3 tasiRNA formation, ARGONAUTE7 (AGO7)–
miR390 complexes interact with primary transcripts at two sites,
resulting in recruitment of RNA-DEPENDENT RNA POLYMERASE6
for dsRNA biosynthesis. An extensive screen for Arabidopsis mutants...
miRNA-guided cleavage initiates entry of primary transcripts into the trans-acting siRNA (tasiRNA) biogenesis pathway involving RNA-DEPENDENT RNA POLYMERASE6 (RDR6), DICER-LIKE 4 (DCL4), and SUPPRESSOR OF GENE SILENCING3 (SGS3). Arabidopsis thaliana TAS1 and TAS2 families yield tasiRNA that form through miR173- guided initiation cleavage on the 5’ side of the siRNA-generating...