TSniffer: Unbiased de novo identification of RNA editing sites and quantification of editing activity in RNA-seq data [re-analysis]
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ABSTRACT:
ORGANISM(S): Mus musculus Homo sapiens
PROVIDER: GSE291676 | GEO | 2025/12/03
REPOSITORIES: GEO
Similar Datasets
Project description:RNA editing by adenosine deaminases acting on RNA (ADARs) is an evolutionarily conserved posttranscriptional modification essential for organismal development and normal cell function. Three catalytically active ADARs are conserved in mammals: two isoforms of ADAR1 referred to as ADAR1-p150 and ADAR1-p110, as well as ADAR2. All recognize and edit double-stranded RNA (dsRNA) structures but demonstrate target specificity and selectivity that dictate the unique essential biological functions of the three enzymes. The editing activity of ADAR1-p150 suppresses autoimmune responses against self-RNA structures, whereas ADAR1-p110 and ADAR2 have other primary functions. To better understand the mechanism of target selection by ADARs, we developed TSniffer, which allows accurate de novo identification of edited transcripts and quantification of the extent of editing within each transcript. We found that 17-40% of protein coding transcripts in mice, ferrets, and humans are edited by ADARs. Individual transcripts can harbor hundreds and thousands of editing sites, mostly within inverted retrotransposable elements. For human transcripts, we found differential editing by ADAR1 and ADAR2, aligning with a supportive role for ADAR2, while some targets were dominantly edited by ADAR1. Relying only on RNA-seq data and reference genome, TSniffer represents a novel tool to decipher the role of ADAR editing in different physiological states including disease models. Its unbiased approach is suitable for any organism.
2025-12-03 | GSE291675 | GEO
Project description:Background: Adenosine deaminases that act on RNA (ADARs) bind to double-stranded and structured RNAs and deaminate adenosines to inosines. This A to I editing is widespread and required for normal life and development. Besides mRNAs and repetitive elements, ADARs can target miRNA precursors. Editing of miRNA precursors can affect processing efficiency and alter target specificity. Interestingly, ADARs can also influence miRNA abundance independent of RNA-editing. In mouse embryos where editing levels are low, ADAR2 was found to be the major ADAR protein that affects miRNA abundance. Here we extend our analysis to adult mouse brains where high editing levels are observed. Results: Using Illumina deep sequencing we compare the abundances of mature miRNAs and editing events within them, between wild-type and ADAR2 knockout mice in the adult mouse brain. Reproducible changes in abundance of specific miRNAs are observed in ADAR2 deficient mice. Most of these quantitative changes seem unrelated to A to I editing events. However, many A to G transitions in cDNAs prepared from mature miRNA sequences, reflecting A to I editing events in the RNA, are observed with frequencies reaching up to 80%. About half of these editing events are primarily caused by ADAR2 while a few miRNAs show increased editing in the absence of ADAR2, suggesting preferential editing by ADAR1. Moreover, novel, previously unknown editing events were identified in several miRNAs. In general 64% of all editing events are located within the seed region of mature miRNAs. In one of these cases retargeting of the edited miRNA could be verified in reporter assays. Also, altered processing efficiency upon editing near a processing site could be experimentally verified. Conclusions: ADAR2 can significantly influence the abundance of certain miRNAs in the brain. Only in a few cases changes in miRNA abundance can be explained by miRNA editing. Thus, ADAR2 binding to miRNA precursors, without editing them, may influence their processing and thereby abundance. ADAR1 and ADAR2 have both overlapping and distinct specificities for editing of miRNA editing sites. Over 60% of editing occurs in the seed region possibly changing target specificities for many edited miRNAs. Examination of the effect of ADAR2 on mature miRNA abundance and sequence in adult mouse brain.
2014-10-02 | E-GEOD-61066 | biostudies-arrayexpress
Project description:RNAseq analysis of cell lines with ADAR1-p150 and ADAR1-p110 knock-outs and primary human tissue samples (from GSE57353 and GSE99392 data sets) to identify sites of ADAR1 editing
2018-12-04 | GSE115127 | GEO
Project description:Background: Adenosine deaminases that act on RNA (ADARs) bind to double-stranded and structured RNAs and deaminate adenosines to inosines. This A to I editing is widespread and required for normal life and development. Besides mRNAs and repetitive elements, ADARs can target miRNA precursors. Editing of miRNA precursors can affect processing efficiency and alter target specificity. Interestingly, ADARs can also influence miRNA abundance independent of RNA-editing. In mouse embryos where editing levels are low, ADAR2 was found to be the major ADAR protein that affects miRNA abundance. Here we extend our analysis to adult mouse brains where high editing levels are observed. Results: Using Illumina deep sequencing we compare the abundances of mature miRNAs and editing events within them, between wild-type and ADAR2 knockout mice in the adult mouse brain. Reproducible changes in abundance of specific miRNAs are observed in ADAR2 deficient mice. Most of these quantitative changes seem unrelated to A to I editing events. However, many A to G transitions in cDNAs prepared from mature miRNA sequences, reflecting A to I editing events in the RNA, are observed with frequencies reaching up to 80%. About half of these editing events are primarily caused by ADAR2 while a few miRNAs show increased editing in the absence of ADAR2, suggesting preferential editing by ADAR1. Moreover, novel, previously unknown editing events were identified in several miRNAs. In general 64% of all editing events are located within the seed region of mature miRNAs. In one of these cases retargeting of the edited miRNA could be verified in reporter assays. Also, altered processing efficiency upon editing near a processing site could be experimentally verified. Conclusions: ADAR2 can significantly influence the abundance of certain miRNAs in the brain. Only in a few cases changes in miRNA abundance can be explained by miRNA editing. Thus, ADAR2 binding to miRNA precursors, without editing them, may influence their processing and thereby abundance. ADAR1 and ADAR2 have both overlapping and distinct specificities for editing of miRNA editing sites. Over 60% of editing occurs in the seed region possibly changing target specificities for many edited miRNAs. Examination of the effect of ADAR2 on gene expression in mature mouse wildtype and ADAR2 knockout brain using AffymetrixM-BM-. GeneChipM-BM-. Whole Transcript (WT) Expression Arrays (Analysis by KFB Regensburg, Germany)
2014-10-02 | E-GEOD-61067 | biostudies-arrayexpress
Project description:We used transgenic mouse embryos that are deficient in the two enzymatically active RNA editing enzymes ADAR1 and ADAR2 to compare relative frequencies but also sequence composition of mature miRNAs in these genetically modified backgrounds to wild-type mice by Illumina next gen sequencing. Deficiency of ADAR2 leads to a reproducible change in abundance of specific miRNAs and their predicted targets. Changes in miRNA abundance seem unrelated to editing events. Additional deletion of ADAR1 has surprisingly little impact on the mature miRNA repertoire, indicating that miRNA expression is primarily dependent on ADAR2. A to G transitions reflecting A to I editing events can be detected at few sites and at low frequency during the early embryonic stage investigated. Again, most editing events are ADAR2 dependent with only few editing sites being specifically edited by ADAR1. Besides known editing events in miRNAs a few novel, previously unknown editing events were identified. Some editing events are located to the seed region of miRNAs opening the possibility that editing leads to their retargeting. GSM852140-8: sequencing of mature miRNAs of wt, ADAR2-/- and ADAR1-/-/ADAR2-/- female mouse embryos at E11.5 GSM863778-81: Gene expression was measured in wiltype, ADAR2-/- and ADAR1-/-/ADAR2-/- E11.5 whole female mouse embryos using Agilent Whole Mouse Genome Oligo Microarrays 8x60K.
2012-02-02 | E-GEOD-34626 | biostudies-arrayexpress
Project description:RNA editing and splicing are the two major processes that dynamically regulate human transcriptome diversity. Despite growing evidence of crosstalk between RNA editing enzymes (mainly ADAR1) and splicing machineries, detailed mechanistic explanations and their biological importance in diseases, such as cancer are still lacking. Herein, we identify approximately a hundred high-confidence splicing events altered by ADAR1 and/or ADAR2, and ADAR1 or ADAR2 protein can regulate cassette exons in both directions. We unravel a binding tendency of ADARs to dsRNAs that involves GA-rich sequences for editing and splicing regulation. ADAR1 edits an intronic splicing silencer, leading to recruitment of SRSF7 and repression of exon inclusion. We also present a mechanism through which ADAR2 binds to dsRNA formed between GA-rich sequences and polypyrimidine (Py)-tract and precludes access of U2AF65 to 3′ splice site. Furthermore, we find these ADARs-regulated splicing changes per se influence tumorigenesis, not merely byproducts of ADARs editing and binding.
2019-12-22 | GSE131658 | GEO
Project description:Background: Adenosine deaminases that act on RNA (ADARs) bind to double-stranded and structured RNAs and deaminate adenosines to inosines. This A to I editing is widespread and required for normal life and development. Besides mRNAs and repetitive elements, ADARs can target miRNA precursors. Editing of miRNA precursors can affect processing efficiency and alter target specificity. Interestingly, ADARs can also influence miRNA abundance independent of RNA-editing. In mouse embryos where editing levels are low, ADAR2 was found to be the major ADAR protein that affects miRNA abundance. Here we extend our analysis to adult mouse brains where high editing levels are observed. Results: Using Illumina deep sequencing we compare the abundances of mature miRNAs and editing events within them, between wild-type and ADAR2 knockout mice in the adult mouse brain. Reproducible changes in abundance of specific miRNAs are observed in ADAR2 deficient mice. Most of these quantitative changes seem unrelated to A to I editing events. However, many A to G transitions in cDNAs prepared from mature miRNA sequences, reflecting A to I editing events in the RNA, are observed with frequencies reaching up to 80%. About half of these editing events are primarily caused by ADAR2 while a few miRNAs show increased editing in the absence of ADAR2, suggesting preferential editing by ADAR1. Moreover, novel, previously unknown editing events were identified in several miRNAs. In general 64% of all editing events are located within the seed region of mature miRNAs. In one of these cases retargeting of the edited miRNA could be verified in reporter assays. Also, altered processing efficiency upon editing near a processing site could be experimentally verified. Conclusions: ADAR2 can significantly influence the abundance of certain miRNAs in the brain. Only in a few cases changes in miRNA abundance can be explained by miRNA editing. Thus, ADAR2 binding to miRNA precursors, without editing them, may influence their processing and thereby abundance. ADAR1 and ADAR2 have both overlapping and distinct specificities for editing of miRNA editing sites. Over 60% of editing occurs in the seed region possibly changing target specificities for many edited miRNAs.
2014-10-02 | GSE61067 | GEO
Project description:Background: Adenosine deaminases that act on RNA (ADARs) bind to double-stranded and structured RNAs and deaminate adenosines to inosines. This A to I editing is widespread and required for normal life and development. Besides mRNAs and repetitive elements, ADARs can target miRNA precursors. Editing of miRNA precursors can affect processing efficiency and alter target specificity. Interestingly, ADARs can also influence miRNA abundance independent of RNA-editing. In mouse embryos where editing levels are low, ADAR2 was found to be the major ADAR protein that affects miRNA abundance. Here we extend our analysis to adult mouse brains where high editing levels are observed. Results: Using Illumina deep sequencing we compare the abundances of mature miRNAs and editing events within them, between wild-type and ADAR2 knockout mice in the adult mouse brain. Reproducible changes in abundance of specific miRNAs are observed in ADAR2 deficient mice. Most of these quantitative changes seem unrelated to A to I editing events. However, many A to G transitions in cDNAs prepared from mature miRNA sequences, reflecting A to I editing events in the RNA, are observed with frequencies reaching up to 80%. About half of these editing events are primarily caused by ADAR2 while a few miRNAs show increased editing in the absence of ADAR2, suggesting preferential editing by ADAR1. Moreover, novel, previously unknown editing events were identified in several miRNAs. In general 64% of all editing events are located within the seed region of mature miRNAs. In one of these cases retargeting of the edited miRNA could be verified in reporter assays. Also, altered processing efficiency upon editing near a processing site could be experimentally verified. Conclusions: ADAR2 can significantly influence the abundance of certain miRNAs in the brain. Only in a few cases changes in miRNA abundance can be explained by miRNA editing. Thus, ADAR2 binding to miRNA precursors, without editing them, may influence their processing and thereby abundance. ADAR1 and ADAR2 have both overlapping and distinct specificities for editing of miRNA editing sites. Over 60% of editing occurs in the seed region possibly changing target specificities for many edited miRNAs.
2014-10-02 | GSE61066 | GEO
Project description:Adenosine deaminases (ADARs) are RNA binding proteins that bind to double stranded RNA and convert adenosine to inosine. Editing creates multiple isoforms of neurotransmitter receptors, including AMPA-subtype Glutamate channels such as Gria2 that is edited to introduce a Q to R amino acid change. Adar2 knock out mice die of seizures shortly after birth, but if the Gria2 Q/R editing site is mutated to mimic the edited version then the animals are viable. We performed RNA-Seq on the frontal cortices of Adar2-/- Gria2R/R mice and their Adar2+/+ Gria2R/R littermates, quantifying overall gene expression, splicing, and A to I editing in a transcriptome-wide fashion. We found 56 editing sites whose level of editing was significantly diminished in the Adar2 deficient animals. The majority of Adar2 responsive editing sites were in the coding regions of genes. Interestingly, other than Adar2 expression, there were only two additional statistically significant differentially expressed genes, Flnb and Cdh13. There were also only three exons that showed statistically significant differences in expression levels between the two genotypes. This work illustrates that ADAR2 is important in site-specific changes of protein coding sequences but has only modest effects on gene expression or splicing in vivo. 6 ADAR2 Knock out frontal cortices and 6 litter mate control frontal cortices from male mice
2016-07-03 | E-GEOD-70588 | biostudies-arrayexpress
Project description:Sensing of double-stranded RNA (dsRNA) is an important component of innate immunity. Proteins like PKR and MDA5 recognize dsRNA and activate various pathways to fight viral infection. In addition to viral dsRNA, many endogenous RNAs containing double-stranded regions can be misrecognized as immunogenic. The RNA editing enzyme ADAR1, specifically its p150 isoform, has been shown to suppress activation of PKR and MDA5 through its A-to-I editing activity. While the cytoplasmic ADAR1-p150 isoform has been well established within this role, the functions of the nuclear ADAR1-p110 isoform are less understood. To address this knowledge gap, we utilized proximity labeling by APEX2 to identify putative ADAR1-p110 interacting proteins. We identified 110 proteins across three breast cancer cell lines that either interact with p110 or are within close proximity. Many of these proteins have known roles in RNA metabolism. Nine of the identified proteins belong to the DEAD or DEAH box families of RNA helicases, including DHX9. DHX9 is overexpressed in breast cancer, with expression closely correlated with that of p110. By co-immunoprecipitation we confirmed that p110 interacts with DHX9. Knockdown of DHX9 in several triple-negative breast cancer cell lines caused cell death and activation of the dsRNA sensor PKR. In two cell lines that are refractory to knockdown of ADAR1, the combined knockdown of DHX9 and ADAR1 caused a substantial increase in PKR activity, where knockdown of either alone had no effect. Knockdown of DHX9 and ADAR1 caused activation of the type I IFN pathway, RNase L and NF-KB signaling. Activation of these proteins and pathways was not seen with individual knockdown of ADAR1 or DHX9. Activation of PKR following combined knockdown of ADAR1 and DHX9 could be rescued by expression of p110, p150, DHX9, and catalytically inactive DHX9. Additionally PKR activation could be rescued by the dsRBM of DHX9, revealing an important role for dsRBMs in suppressing PKR activation. Together these results reveal an important role for DHX9 in suppressing dsRNA sensing by multiple pathways.
2023-08-07 | GSE224677 | GEO