Browse
Submit Data
Databases
API
Help

Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A Dicer-Independent Route for Biogenesis of siRNAs that Direct DNA Methylation in Arabidopsis

ABSTRACT: DNA methylation directed by 24-nucleotide (nt) small interfering RNAs (siRNAs) plays critical roles in gene regulation and transposon silencing in Arabidopsis. Twenty-four-nt siRNAs are known to be processed from double-stranded RNAs by Dicer-like 3 (DCL3) and loaded into the effector Argonaute 4 (AGO4). Here we report a distinct class of siRNAs independent of DCLs (sidRNAs). sidRNAs are present as ladders of ~20 to 60nt in length, often having same 5' ends but differing in 3' ends by 1-nt steps. We further show that sidRNAs are associated with AGO4 and capable of directing DNA methylation. Finally we show that sidRNA production depends on AGO4 and distributive 3'-5' exonucleases. Our findings suggest an alternative route for siRNA biogenesis: precursor transcripts are bound by AGO4 and subsequently subjected to 3'-5' exonucleolytic trimming for maturation. We propose that sidRNAs generated through this route are the initial triggers of de novo DNA methylation. Small RNAs were profiled in Arabidopsis wild type (Col-0), dcl1/2/3/4 and other mutants by Illumina high-throughput sequencing, to identify siRNAs independent of DCLs (sidRNAs) and dissect their biogenesis pathway. DNA methylation was profiled in various mutants by whole-genome bisulfite sequencing to establish a role for sidRNAs in DNA methylation

ORGANISM(S): Arabidopsis thaliana

SUBMITTER: Yijun Qi

PROVIDER: E-GEOD-74398 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

Arabidopsis AGO3 predominantly recruits 24-nucleotide small RNAs to regulate epigenetic silencing [Bisulfite-seq]

Project description:AGO3 predominantly bound 24-nt sRNAs with 5â terminal adenine. The spectrum of AGO3-associated sRNAs was different from those bound to AGO2. By contrast, approximately 30% of AGO3-bound 24-nt sRNAs overlapped with those bound to AGO4 and over 60% of AGO3-associated 24-nt sRNA enriched loci were identical to those of AGO4. In addition, expression of AGO3 driven by AGO4 native promoter partially complemented AGO4 function and rescued DNA methylation defect in ago4-1 background. Examination of DNA methylation using bisulfite conversion of unmethylated cytosines in three genetic backgrounds of Arabidopsis thaliana.

2016-05-31 | E-GEOD-78089 | biostudies-arrayexpress

CMV 2b immunoprecipitated small RNAs data set

Project description:We report that CMV2b exist in a complex of sRNAs in arabidopsis, with significant preference to repeat-associated AGO4-related 24nt siRNAs. This differential selection of siRNAs in vivo helps CMV 2b to perturb host epigenetic defense in the form of transposons activation and severeal repeat associated loci hypomethylation. Examination of CMV 2b presence in sRNAs complex in vivo

2013-01-18 | E-GEOD-23771 | biostudies-arrayexpress

MethylC-Seq of ago6-2, ago4-6 and ago4-6 ago6-2 double mutants

Project description:Using MethylC-Seq to provide single-base resolution of DNA methylation status in ago6-2, ago4-6 and ago4-6 ago6-2 double mutants MethylC-Seq: 3 mutants examined, ago6-2, ago4-6 single mutant and ago4-6 ago6-2 double mutants

2015-01-06 | E-GEOD-56388 | biostudies-arrayexpress

AGO4 slicer activity reveals the passenger strand function of plant 23 nt siRNAs and the post-slicing retention of target RNAs mediating RNA-directed DNA methylation [WGBS]

Project description:In plants, transcriptional silencing by RNA-directed DNA methylation (RdDM) is mediated by ARGONAUTE 4 (AGO4) and 24 nt short-interfering RNAs (siRNAs) that are generated in parallel with 23 nt RNAs of unknown function. We show that 23 nt RNAs serve as the passenger strands of 23/24 nt duplexes loaded into AGO4. The 24 nt siRNAs then guide AGO4 slicing of the passenger strands, generating 11 and 12 nt cleavage products. Unexpectedly, we find that the 12 nt products remain associated with the guide strand-AGO4 complexes. Long noncoding RNAs generated at RdDM loci are similarly sliced and retained by AGO4. These results suggest a model in which RNA POLYMERASE V transcripts at target loci are sliced repeatedly as transcription elongation proceeds, sequentially releasing AGO4-siRNA-scaffold RNA complexes that independently recruit the RdDM machinery. Consistent with this hypothesis, plant lines expressing wild-type versus slicing-defective AGO4 show quantitative variation in cytosine methylation and siRNA levels within RdDM loci.

2023-02-17 | GSE201234 | GEO

AGO4 slicer activity reveals the passenger strand function of plant 23 nt siRNAs and the post-slicing retention of target RNAs mediating RNA-directed DNA methylation [smallRNA-seq]

2023-02-17 | GSE201233 | GEO

A Dicer-Independent Route for Biogenesis of siRNAs that Direct DNA Methylation in Arabidopsis

Project description:DNA methylation directed by 24-nucleotide (nt) small interfering RNAs (siRNAs) plays critical roles in gene regulation and transposon silencing in Arabidopsis. Twenty-four-nt siRNAs are known to be processed from double-stranded RNAs by Dicer-like 3 (DCL3) and loaded into the effector Argonaute 4 (AGO4). Here we report a distinct class of siRNAs independent of DCLs (sidRNAs). sidRNAs are present as ladders of ~20 to 60nt in length, often having same 5' ends but differing in 3' ends by 1-nt steps. We further show that sidRNAs are associated with AGO4 and capable of directing DNA methylation. Finally we show that sidRNA production depends on AGO4 and distributive 3'-5' exonucleases. Our findings suggest an alternative route for siRNA biogenesis: precursor transcripts are bound by AGO4 and subsequently subjected to 3'-5' exonucleolytic trimming for maturation. We propose that sidRNAs generated through this route are the initial triggers of de novo DNA methylation.

2015-12-17 | GSE74398 | GEO

RNA polymerase V targets transcriptional silencing components to promoters of protein-coding genes

Project description:Transcriptional gene silencing controls transposons and other repetitive elements through RNA-directed DNA methylation (RdDM) and heterochromatin formation. A key component of the Arabidopsis RdDM pathway is ARGONAUTE4 (AGO4), which associates with sizs to mediate DNA methylation. Here, we show that AGO4 preferentially targets transposable elements embedded within promoters of protein-coding genes. This pattern of AGO4 binding cannot be simply explained by the sequences of AGO4-bound siRNAs; instead, AGO4 binding to specific gene promoters is also mediated by long non-coding RNAs (lncRNAs) produced by RNA polymerase V. lncRNA-mediated AGO4 binding to gene promoters directs asymmetric DNA methylation to these genomic regions and is involved in regulating the expression of targeted genes. Finally, AGO4 binding overlaps sites of DNA methylation affected by the biotic stress response. Based on these findings, we propose that the targets of AGO4-directed RdDM are regulatory units responsible for controlling gene expression under specific environmental conditions. ChIP-seq experiments using AGO4 antibody of WT (Col-0) and ago4 or nrpe1 mutant plants of Arabidopsis thaliana

2012-10-17 | E-GEOD-35381 | biostudies-arrayexpress

RNA polymerase V targets transcriptional silencing components to promoters of protein-coding genes

2012-10-17 | GSE35381 | GEO

Sequence Features Accurately Predict Genome-wide MeCP2 Binding in vivo

Project description:MECP2 is critical for proper brain development and expressed at near-histone levels in neurons, but the mechanism of its genomic localization remains poorly understood. Using high-resolution MeCP2 binding data, we show that genetic features alone can predict binding with 88% accuracy. Integrating MeCP2 binding and DNA methylation in a probabilistic graphical model, we demonstrate that previously reported methylation preferences may be due to MeCP2âs affinity to GC-rich chromatin, a result replicated using published data. Furthermore, MeCP2 co-localized with nucleosomes, and Mecp2 deletion led to nucleosome repositioning. Finally, MeCP2 binding downstream of promoters correlated with increased expression in Mecp2 deficient neurons. Study of genetic and epigenetic determinants of MeCP2 binding using MeCP2 ChIP-seq, MNase-seq, Bisulfite-seq and RNA-seq. Please see individual sample record for details on experimental design.

2016-03-24 | E-GEOD-71126 | biostudies-arrayexpress

Arabidopsis AGO3 predominantly recruits 24-nucleotide small RNAs to regulate epigenetic silencing

Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series

2016-05-31 | E-GEOD-78090 | biostudies-arrayexpress