{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Cuperus JT"],"funding":["NIAID NIH HHS"],"pagination":["997-1003"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC2916640"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["17(8)"],"pubmed_abstract":["RNA interference pathways can involve amplification of secondary siRNAs by RNA-dependent RNA polymerases. In plants, RDR6-dependent secondary siRNAs arise from transcripts targeted by some microRNAs (miRNAs). Here, Arabidopsis thaliana secondary siRNAs from mRNA as well as trans-acting siRNAs are shown to be triggered through initial targeting by a 22-nucleotide (nt) miRNA that associates with AGO1. In contrast to canonical 21-nt miRNAs, 22-nt miRNAs primarily arise from foldback precursors containing asymmetric bulges. Using artificial miRNA constructs, conversion of asymmetric foldbacks to symmetric foldbacks resulted in the production of 21-nt forms of miR173, miR472 and miR828. Both 21- and 22-nt forms associated with AGO1 and guided accurate slicer activity, but only 22-nt forms were competent to trigger RDR6-dependent siRNA production from target RNA. These data suggest that AGO1 functions differentially with 21- and 22-nt miRNAs to engage the RDR6-associated amplification apparatus."],"journal":["Nature structural & molecular biology"],"pubmed_title":["Unique functionality of 22-nt miRNAs in triggering RDR6-dependent siRNA biogenesis from target transcripts in Arabidopsis."],"pmcid":["PMC2916640"],"funding_grant_id":["AI43288","R21 AI043288","R37 AI043288","R01 AI043288"],"pubmed_authors":["Carrington JC","Gilbert SD","Fahlgren N","Garcia-Ruiz H","Takeda A","Cuperus JT","Burke RT","Sullivan CM","Montgomery TA","Carbonell A"],"additional_accession":[]},"is_claimable":false,"name":"Unique functionality of 22-nt miRNAs in triggering RDR6-dependent siRNA biogenesis from target transcripts in Arabidopsis.","description":"RNA interference pathways can involve amplification of secondary siRNAs by RNA-dependent RNA polymerases. In plants, RDR6-dependent secondary siRNAs arise from transcripts targeted by some microRNAs (miRNAs). Here, Arabidopsis thaliana secondary siRNAs from mRNA as well as trans-acting siRNAs are shown to be triggered through initial targeting by a 22-nucleotide (nt) miRNA that associates with AGO1. In contrast to canonical 21-nt miRNAs, 22-nt miRNAs primarily arise from foldback precursors containing asymmetric bulges. Using artificial miRNA constructs, conversion of asymmetric foldbacks to symmetric foldbacks resulted in the production of 21-nt forms of miR173, miR472 and miR828. Both 21- and 22-nt forms associated with AGO1 and guided accurate slicer activity, but only 22-nt forms were competent to trigger RDR6-dependent siRNA production from target RNA. These data suggest that AGO1 functions differentially with 21- and 22-nt miRNAs to engage the RDR6-associated amplification apparatus.","dates":{"release":"2010-01-01T00:00:00Z","publication":"2010 Aug","modification":"2026-05-03T14:31:46.502Z","creation":"2026-04-07T19:20:19.254Z"},"accession":"S-EPMC2916640","cross_references":{"pubmed":["20562854"],"doi":["10.1038/nsmb.1866"]}}