A specific dsRNA-binding protein complex selectively sequesters endogenous Inverted-Repeat siRNA precursors and inhibits their processing.
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ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE92309 | GEO | 2016/12/14
SECONDARY ACCESSION(S): PRJNA357198
REPOSITORIES: GEO
Similar Datasets
Project description:Arabidopsis thaliana (Arabidopsis) encodes five DOUBLE-STRANDED RNA BINDING (DRB) proteins, DRB1 to DRB5, that predominantly act as non-catalytic cofactors for DICER-LIKE (DCL) proteins in the double-stranded RNA (dsRNA) processing stages of small RNA (sRNA) production pathways. In the nucleus, DRB1 is required for microRNA (miRNAs) processing from imperfectly dsRNA precursors by DCL1. Similarly, DRB4 is required by DCL4 for small-interfering RNAs (siRNAs) production from endogenous or exogenous perfectly dsRNA templates. DRB2 has been recently demonstrated to be required for miRNA and siRNA production in developmentally-important tissues of Arabidopsis while the requirement of either DRB3 or DRB5 in sRNA production remains unclear. Here, we analyse in parallel, the contribution of all five DRB protein family members to the global sRNA landscape of Arabidopsis floral tissues. In depth bioinformatic analysis of sRNA sequencing datasets generated from floral tissues of DRB knockout mutant (drb) plant lines, drb1, drb2, drb4, drb12, drb14, drb24, and drb35 and their comparison to the floral sRNA profile of wild-type Arabidopsis, has enabled confident assignment of the requirement of DRB1, DRB2 and DRB4 for the production of specific miRNA and siRNA subclasses in this tissue. Our analyses have additionally identified novel and/or expanded roles for DRB2 in miRNA, trans-acting siRNAs (tasiRNAs) and natural antisense transcript siRNAs (natsiRNAs) production.
2017-09-09 | GSE73752 | 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: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:DICER-like proteins produce small RNAs that silence genes involved in development and defenses against viruses and pathogens. Which DCLs participate in plant-herbivore interactions remains unstudied. We identified four distinct DCL genes and stably silenced their expression by RNAi in Nicotiana attenuata, a model system for the study of plant-herbivore interactions. Silencing DCL1 expression was lethal to the plants. Manduca sexta larvae performed significantly better on ir-dcl3and ir-dcl4 plants, but not on ir-dcl2 plants compared to wild type plants. Phytohormones, defense metabolites and microarray analyses revealed that when DCL3 and DCL4 were silenced separately, herbivore resistance traits were regulated in distinctly different ways. Crossing of the lines revealed complex interactions in the patterns of regulation. Single ir-dcl4 and double ir-dcl2/ ir-dcl3 plants were impaired in JA accumulation, while JA-Ile was increased in ir-dcl3 plants. Ir-dcl3 and ir-dcl4 plants were impaired in nicotine accumulation; silencing DCL2 in combination with either DCL3 or DCL4 restored nicotine levels to those of WT. Trypsin proteinase inhibitor activity and transcripts were only silenced in ir-dcl3 plants. We conclude that DCL2/3/4 interact in a complex manner to regulate anti-herbivore defenses and that these interactions significantly complicate the already challenging task of understanding smRNA function in the regulation of biotic interactions.
2013-12-24 | GSE30124 | GEO
Project description:DICER-like proteins produce small RNAs that silence genes involved in development and defenses against viruses and pathogens. Which DCLs participate in plant-herbivore interactions remains unstudied. We identified four distinct DCL genes and stably silenced their expression by RNAi in Nicotiana attenuata, a model system for the study of plant-herbivore interactions. Silencing DCL1 expression was lethal to the plants. Manduca sexta larvae performed significantly better on ir-dcl3and ir-dcl4 plants, but not on ir-dcl2 plants compared to wild type plants. Phytohormones, defense metabolites and microarray analyses revealed that when DCL3 and DCL4 were silenced separately, herbivore resistance traits were regulated in distinctly different ways. Crossing of the lines revealed complex interactions in the patterns of regulation. Single ir-dcl4 and double ir-dcl2/ ir-dcl3 plants were impaired in JA accumulation, while JA-Ile was increased in ir-dcl3 plants. Ir-dcl3 and ir-dcl4 plants were impaired in nicotine accumulation; silencing DCL2 in combination with either DCL3 or DCL4 restored nicotine levels to those of WT. Trypsin proteinase inhibitor activity and transcripts were only silenced in ir-dcl3 plants. We conclude that DCL2/3/4 interact in a complex manner to regulate anti-herbivore defenses and that these interactions significantly complicate the already challenging task of understanding smRNA function in the regulation of biotic interactions. Gene expression in leaves of Nicotiana attenuata wild type, irDCL3 and irDCL4 plants was measured at 1 hour after elicitation with oral secretions of Manduca sexta larvae. Three independent experiments were performed with wild type plants and three independent experiments were performed with irDCL3 and irDCL4 plants. A total of 811 genes were identified as differentially regulated in irDCL3 and irDCL4 compared to wild type plants.
2013-12-24 | E-GEOD-30124 | biostudies-arrayexpress
Project description:In the model plant Arabidopsis thaliana, four Dicer-like proteins (DCL1-4) mediate the production of various classes of small RNAs (sRNAs). Among these four proteins, DCL4 is by far the most versatile RNaseIII-like enzyme and previously identified dcl4 missense alleles were shown to uncouple the production of the various classes of DCL4-dependent sRNAs. Yet, little is known about the molecular mechanism pertaining this uncoupled production. Here, by studying the subcellular localization, interactome and binding to the sRNA precursors of three distinct dcl4 missense alleles, we simultaneously highlight the absolute requirement of its helicase domain for efficient production of all DCL4-dependent sRNAs, and identify an important determinant of DCL4 versatility within its PAZ domain that is mandatory for efficient processing of intramolecular foldback dsRNA precursors but dispensable for the production of siRNAs from RDR-dependent dsRNA susbtrates. This study not only provides novel insights into DCL4 mode of action in plants but also delineates interesting tools to further study the complexity of plant RNA silencing pathways.
2018-04-24 | GSE106383 | GEO
Project description:RNaseIII enzymes catalyze the cleavage of double stranded RNA (dsRNA) and have diverse functions in RNA maturation. Arabidopsis RNASE THREE LIKE2 (RTL2) carries one RNaseIII and two dsRNA-binding (DRB) domains, and is the unique Arabidopsis RNAse III enzyme resembling the budding yeast siRNA-producing Dcr1 enzyme. Here we show that RTL2 modulates the production of siRNAs, and that this activity depends on both RNaseIII and DRB domains. However, RTL2 mode of action differs from that of Dcr1. Indeed, whereas Dcr1 directly cleaves dsRNAs into 23-nt siRNAs, RTL2 likely cleaves dsRNAs into molecules longer than siRNAs, which are subsequently processed by the DCL enzymes. Depending on the dsRNA considered, RTL2-mediated maturation either improves (RTL2- dependent loci) or reduces the efficiency of DCL processing (RTL2-sensitive loci). Because the vast majority of plant small RNAs are 24-nt siRNAs that guide DNA methylation at transposons and intergenic regions, RTL2 depletion mostly modifies DNA methylation in these regions. Nevertheless, 13% of the siRNA-producing loci affected by RTL2 depletion correspond to protein coding genes. We show that changes in 24-nt siRNA levels also affect DNA methylation levels at such loci, and inversely correlate with mRNA steady-state levels, thus implicating RTL2 in the control of protein-coding gene expression.
2015-10-01 | GSE71782 | GEO
Project description:In response to infection, viral genomes are processed by Dicer-like (DCL) ribonuclease proteins into viral small RNAs (vsRNAs) of discrete sizes. vsRNAs are then used as guides for silencing the viral genome. The profile of vsRNAs produced during the infection process has been extensively studied for some group of viruses. However, nothing is known for members of the economically important family Luteoviridae, a group of phloem-restricted viruses. Here, the population of vsRNAs from cotton plants infected with Cotton leafroll dwarf virus (CLRDV), a member of the genus Polerovirus, family Luteoviridae, is characterized.Deep sequencing of small RNAs (sRNAs) from CLRDV-infected cotton leaves was performed. Results showed 21-nt to 24-nt long vsRNAs matching all the viral genome, with a higher frequency of matches in the 3M-CM-"M-BM-^@M-BM-^Y region. Equivalent amounts of sense and antisense vsRNAs were found, and the 22-nt long small RNA class was the most prominent one. Looking for cotton Dcl transcripts levels during infection, we could observe that Dcl4 seems to be up-regulated, while Dcl2 seems to be down-regulated.This is the first report on the profile of sRNAs coming from a plant infected with a member of the family Luteoviridae. Our sequence data strongly suggest that virus-derived double-stranded RNA functions as one of the main precursors of vsRNAsOur results indicate that secondary structures of the viral RNAs are not the main source of the viRNAs observed, as suggested for other viruses. Judging by the profiled size classes, all cotton DCLs might be working to silence the virus. The possible causes for the unexpected high accumulation of 22-nt viRNAvsRNAs are discussed. CLRDV is the causal agent of worldwide cotton pathology named Cotton blue disease. Our results are an important contribution for understanding the molecular mechanisms involved in this and related diseases. Total RNA obtained from leaves of the cotton plant 5 days post-infection with Cotton leafrol dawrf virus (CLRDV) compared to not-infected control.
2012-07-16 | E-GEOD-31062 | biostudies-arrayexpress
Project description:In plants, small interfering RNAs (siRNAs) are a quintessential class of RNA interference (RNAi)-inducing molecules produced by the endonucleolytic cleavage of double stranded RNAs (dsRNAs). In order to ensure robust RNAi, siRNAs are amplified through a positive feedback mechanism called transitivity. Transitivity relies on RNA-DIRECTED-RNA POLYMERASE 6 (RDR6)-mediated dsRNA synthesis using siRNA-targeted RNA. The newly synthesized dsRNA is subsequently cleaved into secondary siRNAs by DICER-LIKE (DCL) endonucleases. Just like primary siRNAs, secondary siRNAs are also loaded into ARGONAUTE proteins (AGOs) to form an RNA-induced silencing complex (RISC) reinforcing the cleavage of the target RNA. Although the molecular players underlying transitivity are well established, the mode of action of transitivity remains elusive. In this study, we investigated the influence of primary target sites on transgene silencing and transitivity using the GFP-expressing Nicotiana benthamiana 16C line, high pressure spraying protocol (HPSP), and synthetic 22-nucleotide (nt) long siRNAs. We found that the 22-nt siRNA targeting the 3’ of the GFP transgene was less efficient in inducing silencing when compared to the siRNAs targeting the 5’ and middle region of the GFP. Moreover, sRNA sequencing of locally silenced leaves showed that the amount but not the profile of secondary RNAs is shaped by the occupancy of the primary siRNA triggers on the target RNA. Our findings suggest that RDR6-mediated dsRNA synthesis is not primed by primary siRNAs and that dsRNA synthesis appears to be generally initiated at the 3’ end of the target RNA.
2021-12-01 | GSE189777 | GEO
Project description:In response to infection, viral genomes are processed by Dicer-like (DCL) ribonuclease proteins into viral small RNAs (vsRNAs) of discrete sizes. vsRNAs are then used as guides for silencing the viral genome. The profile of vsRNAs produced during the infection process has been extensively studied for some group of viruses. However, nothing is known for members of the economically important family Luteoviridae, a group of phloem-restricted viruses. Here, the population of vsRNAs from cotton plants infected with Cotton leafroll dwarf virus (CLRDV), a member of the genus Polerovirus, family Luteoviridae, is characterized.Deep sequencing of small RNAs (sRNAs) from CLRDV-infected cotton leaves was performed. Results showed 21-nt to 24-nt long vsRNAs matching all the viral genome, with a higher frequency of matches in the 3â region. Equivalent amounts of sense and antisense vsRNAs were found, and the 22-nt long small RNA class was the most prominent one. Looking for cotton Dcl transcripts levels during infection, we could observe that Dcl4 seems to be up-regulated, while Dcl2 seems to be down-regulated.This is the first report on the profile of sRNAs coming from a plant infected with a member of the family Luteoviridae. Our sequence data strongly suggest that virus-derived double-stranded RNA functions as one of the main precursors of vsRNAsOur results indicate that secondary structures of the viral RNAs are not the main source of the viRNAs observed, as suggested for other viruses. Judging by the profiled size classes, all cotton DCLs might be working to silence the virus. The possible causes for the unexpected high accumulation of 22-nt viRNAvsRNAs are discussed. CLRDV is the causal agent of worldwide cotton pathology named Cotton blue disease. Our results are an important contribution for understanding the molecular mechanisms involved in this and related diseases.
2012-07-16 | GSE31062 | GEO