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ABSTRACT:
PROVIDER: PRJNA523113 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:In plants, the biogenesis of 24 nt and 23 nt small interfering RNAs (siRNAs) requires NUCLEAR RNA POLYMERASE IV (Pol IV), RNA-DEPENDENT RNA POLYMERASE 2 (RDR2) and DICER-LIKE 3 (DCL3). We show that single-stranded M13 bacteriophage DNA can be used as a template for siRNA synthesis in vitro. Deep sequencing of RNAs produced from the in vitro reactions of Pol IV, RDR2 and DCL3 shows that Pol IV transcribes the DNA into first-strand RNAs which RDR2 then uses as templates to synthesize complementary second strands. These siRNA precursor transcripts made by Pol IV and RDR2 are mostly 30-50 nt. An untemplated 3' terminal nucleotide is a characteristic of RDR2 transcripts. DCL3 dicing of double-stranded precursor RNAs synthesized by Pol IV and RDR2 generates siRNAs that are mostly 24 nt, with a smaller population of 23 nt also produced.
2019-07-01 | GSE126086 | GEO
Project description:Endogenous small interfering (esi)RNAs repress mRNA levels and retrotransposon (retroTn) mobility in Drosophila somatic cells. EsiRNAs are primarily generated from transposon and inverted repeat (hairpin) loci in Drosophila culture cells. After discovering a nucleus specific physical interaction between the essential esiRNA cleavage enzyme Dcr2 and Symplekin, a component of the core cleavage complex (CCC) required for 3’ end processing of mRNAs, we investigated cellular localization of esiRNA biogenesis and overlap between these pathways. We found that knockdown of CCC components perturbs esiRNA levels and that retroTn precursor transcripts are highly enriched in the nucleus while hairpin RNAs are predominantly cytoplasmic. Additionally, retroTn and hairpin-derived esiRNAs have distinct physical characteristics. Combined, these observations support a novel mechanism in which differences in localization of esiRNA precursors impacts esiRNA biogenesis; hairpin-derived esiRNAs are generated in the cytoplasm independent of Dcr2-Symplekin interactions, while retroTns are processed in the nucleus.
2017-06-01 | GSE82128 | GEO
Project description:In eukaryotes, small RNAs (sRNAs) play critical roles in multiple biological processes. Dicer endonucleases are central to sRNA biogenesis. In plants, DICER-LIKE PROTEIN 3 (DCL3) produces 24-nt small interfering RNAs (siRNAs) that determine the specificity of the RNA-directed DNA methylation (RdDM) pathway. Here, we determined structure of a DCL3-pre-siRNA complex in an active dicing-competent state. The 5′-phosphorylated-A1 of the guide strand and the 1-nt 3′-overhang of the complementary strand are specifically recognized by a positively charged pocket and an aromatic cap, respectively. The 24-nt siRNA length dependence relies on the separation between the 5′-phosphorylated-end of the guide RNA and dual cleavage sites formed by the paired RNaseIII domains. These structural studies, complemented by functional data, reveal insights into the dicing principle for Dicers in general.
2021-10-14 | GSE179616 | GEO
Project description:Small RNAs play essential regulatory roles in genome stability, development and stress responses in most eukaryotes. Plants encode DICER-LIKE (DCL) RNaseIII enzymes, including DCL1, which produces miRNAs, and DCL2, DCL3 and DCL4, which produce diverse size classes of siRNA. Plants also encode RNASE THREE-LIKE (RTL) enzymes that lack DCL-specific domains and whose function is largely unknown. Small RNA sequencing in plants over-expressing RTL1 or RTL2 or lacking RTL2 revealed that RTL1 over-expression inhibits the accumulation of all types of small RNAs produced by DCL2, DCL3 and DCL4, indicating that RTL1 is a general suppressor of plant siRNA pathways. By contrast, RTL2 plays minor, if any, role in the small RNA repertoire. In vivo and in vitro assays revealed that RTL1 prevents siRNA production by degrading dsRNA before they are processed by DCL2, DCL3 and DCL4. The substrate of RTL1 cleavage is likely long perfect (or near-perfect) dsRNA, consistent with the RTL1-insensitivity of miRNAs, which derive from short imperfect dsRNA. RTL1 is naturally expressed only weakly in roots, but virus infection strongly induces its expression in leaves, suggesting that RTL1 induction is a general strategy used by viruses to counteract the siRNA-based plant antiviral defense. Accordingly, transgenic plants over-expressing RTL1 are more sensitive to TYMV infection than wild-type plants, likely because RTL1 prevents the production of antiviral siRNAs. However, TCV, TVCV and CMV, which encode stronger suppressors of RNA silencing (VSR) than TYMV, are insensitive to RTL1 over-expression. Indeed, TCV VSR inhibits RTL1 activity, suggesting that inducing RTL1 expression and dampening RTL1 activity is a dual strategy used by viruses to establish a successful infection. These results reveal another level of complexity in the evolutionary battle between viruses and plant defenses. Flower sRNA profiles in diverse conditions involving RTL1 and RTL2
2013-09-10 | E-GEOD-49866 | biostudies-arrayexpress
Project description:MiRNA isoforms (isomiRs) are single stranded small RNAs originating from the same pri-miRNA hairpin as a result of cleavage by Drosha and Dicer enzymes. Variations at the 5’-end of a miRNA alter the seed region of the molecule, thus affecting the targetome of the miRNA. MDA-MB-231 cells were transduced with shRNAs against ELOVL5 and luciferase genes. Small RNA sequencing was used to study the cleavage profiles of shRNAs.
2021-05-03 | GSE173709 | GEO
Project description:DCL3 appeared several times in a forward genetic screen meant to isolate genes involved in miRNA-mediated RNA silencing in Chlamydomonas reinhardtii. Because of that, and in order to define the role of DCL3 in the processing of small RNAs on a genome-wide basis, we sequence the small RNA transcriptome of dcl3 mutant and parental lines.
2016-02-01 | E-MTAB-3851 | biostudies-arrayexpress
Project description:Small RNAs play essential regulatory roles in genome stability, development and stress responses in most eukaryotes. Plants encode DICER-LIKE (DCL) RNaseIII enzymes, including DCL1, which produces miRNAs, and DCL2, DCL3 and DCL4, which produce diverse size classes of siRNA. Plants also encode RNASE THREE-LIKE (RTL) enzymes that lack DCL-specific domains and whose function is largely unknown. Small RNA sequencing in plants over-expressing RTL1 or RTL2 or lacking RTL2 revealed that RTL1 over-expression inhibits the accumulation of all types of small RNAs produced by DCL2, DCL3 and DCL4, indicating that RTL1 is a general suppressor of plant siRNA pathways. By contrast, RTL2 plays minor, if any, role in the small RNA repertoire. In vivo and in vitro assays revealed that RTL1 prevents siRNA production by degrading dsRNA before they are processed by DCL2, DCL3 and DCL4. The substrate of RTL1 cleavage is likely long perfect (or near-perfect) dsRNA, consistent with the RTL1-insensitivity of miRNAs, which derive from short imperfect dsRNA. RTL1 is naturally expressed only weakly in roots, but virus infection strongly induces its expression in leaves, suggesting that RTL1 induction is a general strategy used by viruses to counteract the siRNA-based plant antiviral defense. Accordingly, transgenic plants over-expressing RTL1 are more sensitive to TYMV infection than wild-type plants, likely because RTL1 prevents the production of antiviral siRNAs. However, TCV, TVCV and CMV, which encode stronger suppressors of RNA silencing (VSR) than TYMV, are insensitive to RTL1 over-expression. Indeed, TCV VSR inhibits RTL1 activity, suggesting that inducing RTL1 expression and dampening RTL1 activity is a dual strategy used by viruses to establish a successful infection. These results reveal another level of complexity in the evolutionary battle between viruses and plant defenses.
2013-09-10 | GSE49866 | GEO
Project description:To investigate the effects of dcl3,dcl4,mDCL,rdr2,rdr6,nrpd1b, and nrpd1c mutations upon small RNAs in Physcomitrella patens , small RNA-seq was performed.
2015-06-30 | GSE51419 | GEO
Project description:Canonical small interfering RNAs (siRNAs) are generated by the cleavage of double-stranded RNA (dsRNA) by the ribonuclease Dicer. siRNAs are found in plants, animals, and some fungi where they bind to Argonautes to direct RNA silencing. In this study, we characterized the canonical Dicer-dependent siRNAs of C. elegans. We identified thousands of endogenous loci, representing dozens of unique elements, that give rise to low to moderate levels of siRNAs, called 23H-RNAs. These loci include repetitive elements, alleged coding genes, pseudogenes, non-coding RNAs, and unannotated features, many of which adopt hairpin structures.
2024-01-29 | GSE254442 | GEO
Project description:Endogenous 24nt short interfering RNAs (siRNAs) derived mostly from intergenic and repetitive genomic regions constitute a major class of endogenous small RNAs in Arabidopsis thaliana. Accumulation of A. thaliana 24nt siRNAs requires the Dicer family member DCL3, and clear homologs of DCL3 exist in both flowering and non-flowering plants. However, the absence of a conspicuous 24nt peak in the total RNA populations of several non-flowering plants has raised the question of whether this class of siRNAs might, in contrast to the ancient 21nt microRNAs (miRNAs) and 21-22nt trans-acting siRNAs (tasiRNAs), be an angiosperm-specific innovation. Analysis of non-miRNA, non-tasiRNA hotspots of small RNA production within the genome of the moss Physcomitrella patens revealed multiple loci which consistently produced a mixture of 21-24nt siRNAs with a peak at 23nts. These Pp23SR loci were significantly enriched in transposon content, depleted in overlap with annotated genes, and typified by dense concentrations of the 5-methyl cytosine (5mC) DNA modification. Deep sequencing of small RNAs from two independent Ppdcl3 mutants showed that the P. patens DCL3 homolog is required for the accumulation of 22-24nt siRNAs, but not 21nt siRNAs, at Pp23SR loci. The 21nt component of Pp23SR-derived siRNAs was also unaffected by a mutation in the RNA-dependent RNA polymerase mutant Pprdr6. Transcriptome-wide, Ppdcl3 mutants specifically failed to accumulate 23 and 24nt small RNAs from repetitive regions. We conclude that intergenic/repeat-derived siRNAs are indeed a broadly conserved, distinct class of small regulatory RNAs within land plants. Our results also suggest that Pp DCL3 produces siRNAs of heterogenous size, unlike its A. thaliana homolog which generates exclusively 24nt siRNAs.
2008-12-19 | GSE12468 | GEO