Knockout of circRNAs by base editing back-splice sites of circularized exons
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE172193 | GEO | 2021/12/01
REPOSITORIES: GEO
Similar Datasets
Project description:Many circular RNAs (circRNAs) are produced from back-splicing of exons of precursor mRNAs and are generally co-expressed with cognate linear RNAs. Methods for circRNA-specific knockout are lacking, largely due to sequence overlaps between forms. Here, we use base editors (BEs) for circRNA depletion. By targeting splice sites involved in both back-splicing and canonical splicing, BEs can repress circular and linear RNAs. Targeting sites predominantly for circRNA biogenesis, BEs could efficiently repress the production of circular but not linear RNAs. As hundreds of exons are predominantly back-spliced to produce circRNAs, this provides an efficient method to deplete circRNAs for functional study.
| S-EPMC8744252 | biostudies-literature
Project description:Knockout of circRNAs by base editing back-splice sites of circularized exons
| PRJNA722401 | ENA
Project description:Circular RNAs (circRNAs) are upregulated during neurogenesis. Where and how circRNAs are localized, and what roles they play during this process have remained elusive. By comparing the nuclear and cytoplasmic circRNAs between H9 cells and H9-derived forebrain neurons (FB), we found a subset of adenosine (A)-rich circRNAs are restricted in H9 nuclei but exported to cytosols upon forebrain neuron differentiation. This differentiation-coupled circRNA subcellular relocation is modulated by the poly(A)-binding protein PABPC1. In the nucleus, newly produced (A)-rich circRNAs are bound by PABPC1 and the nuclear basket protein TPR to prevent their nucleocytoplasmic export. Modulation of (A)-rich motifs in circRNAs remarkably alters their subcellular localization. Enforced (A)-rich circRNAs in cytosols result in mRNA translation suppression. Furthermore, decreased nuclear PABPC1 upon neuronal differentiation enables the export of (A)-rich circRNAs including circRTN4(2,3), which is required for neurite outgrowth. These findings uncover subcellular localization features of circRNAs, linking their processing and function during neurogenesis.
2024-04-30 | GSE265924 | GEO
Project description:Circular RNAs (circRNAs) are upregulated during neurogenesis. Where and how circRNAs are localized, and what roles they play during this process have remained elusive. By comparing the nuclear and cytoplasmic circRNAs between H9 cells and H9-derived forebrain neurons (FB), we found a subset of adenosine (A)-rich circRNAs are restricted in H9 nuclei but exported to cytosols upon forebrain neuron differentiation. This differentiation-coupled circRNA subcellular relocation is modulated by the poly(A)-binding protein PABPC1. In the nucleus, newly produced (A)-rich circRNAs are bound by PABPC1 and the nuclear basket protein TPR to prevent their nucleocytoplasmic export. Modulation of (A)-rich motifs in circRNAs remarkably alters their subcellular localization. Enforced (A)-rich circRNAs in cytosols result in mRNA translation suppression. Furthermore, decreased nuclear PABPC1 upon neuronal differentiation enables the export of (A)-rich circRNAs including circRTN4(2,3), which is required for neurite outgrowth. These findings uncover subcellular localization features of circRNAs, linking their processing and function during neurogenesis.
2024-04-30 | GSE265930 | GEO
Project description:To explore the overall circRNAs involved in growth and development of Arabidopsis thaliana across the lifespan, we deeply sequenced samples of whole plants from different developmental stages (cotyledons emergence, rosette leavesï¹¥1 mm, rosette growth complete, first flower open, flourishing florescence, first silique shattered, senescence). The total RNA was purified by rRNA-depletion and linear RNA removal with RNAseR, and sequenced by the Illumina HiSeq2500 platform. We obtained 31 Gb raw data and identified 1217 circRNAs with expression quantity. We annotated these circRNAs and predicted their targeted microRNA. The circRNAs involved in growth and development of Arabidopsis thaliana across lifespan were identified and analyzed using the Illumina HiSeq2500 platform.
2016-09-01 | E-GEOD-77672 | biostudies-arrayexpress
Project description:Circular RNAs (circRNAs) are a relatively new class of RNA molecules, and knowledge about their biogenesis and function is still in its infancy. It was recently shown that alternative splicing underlies the formation of circular RNAs (circRNA) arising from the Titin (TTN) gene. Since the main mechanism by which circRNAs are formed is still unclear, we hypothesized that alternative splicing, and in particular exon skipping, is a major driver of circRNA production. We performed RNA sequencing on human and mouse hearts, mapped alternative splicing events, and overlaid these with expressed circRNAs at exon-level resolution. In addition, we performed RNA sequencing on hearts of Rbm20 KO mice to address how important Rbm20-mediated alternative splicing is in the production of cardiac circRNAs. In human and mouse hearts, we show that cardiac circRNAs are mostly (∼90%) produced from constitutive exons and less (∼10%) from alternatively spliced exons. In Rbm20 KO hearts, we identified 38 differentially expressed circRNAs of which 12 were produced from the Ttn gene. Even though Ttn appeared the most prominent target of Rbm20 for circularization, we also detected Rbm20-dependent circRNAs arising from other genes including Fan1, Stk39, Xdh, Bcl2l13, and Sorbs1 Interestingly, only Ttn circRNAs seemed to arise from Rbm20-mediated skipped exons. In conclusion, cardiac circRNAs are mostly derived from constitutive exons, suggesting that these circRNAs are generated at the expense of their linear counterpart and that circRNA production impacts the accumulation of the linear mRNA.
| S-EPMC5959250 | biostudies-literature
Project description:Alternative 3' and 5' splice site (ss) events constitute a significant part of all alternative splicing events. These events were also found to be related to several aberrant splicing diseases. However, only few of the characteristics that distinguish these events from alternative cassette exons are known currently. In this study, we compared the characteristics of constitutive exons, alternative cassette exons, and alternative 3'ss and 5'ss exons. The results revealed that alternative 3'ss and 5'ss exons are an intermediate state between constitutive and alternative cassette exons, where the constitutive side resembles constitutive exons, and the alternative side resembles alternative cassette exons. The results also show that alternative 3'ss and 5'ss exons exhibit low levels of symmetry (frame-preserving), similar to constitutive exons, whereas the sequence between the two alternative splice sites shows high symmetry levels, similar to alternative cassette exons. In addition, flanking intronic conservation analysis revealed that exons whose alternative splice sites are at least nine nucleotides apart show a high conservation level, indicating intronic participation in the regulation of their splicing, whereas exons whose alternative splice sites are fewer than nine nucleotides apart show a low conservation level. Further examination of these exons, spanning seven vertebrate species, suggests an evolutionary model in which the alternative state is a derivative of an ancestral constitutive exon, where a mutation inside the exon or along the flanking intron resulted in the creation of a new splice site that competes with the original one, leading to alternative splice site selection. This model was validated experimentally on four exons, showing that they indeed originated from constitutive exons that acquired a new competing splice site during evolution.
| S-EPMC1876488 | biostudies-literature
Project description:We systemically investigated the circRNA profiles among the subcellular fractions of HepG2 cell, including nucleus, cytoplasm, mitochondria, ribosome, cytosol and exosome. Our studies reveals the wide distribution of circRNAs among the subcellular fractions except the mitochondria. Further comparative analysis indicate the differential subcellular distributions in expression, length, GC content, classification, alternative circularization and function of the parental genes. Through analyzing the binding motifs distribution of the transport-related RBPs among the subcellular circRNAs, we found that the different subcellular distribution characteristics of circRNAs might be resulted from the RBP-mediated selective transportation. It also implies that the circRNAs may follow the same transportation mechanism as linear RNAs: the RBPs specially recognize, bind to and transport the RNAs with the corresponding binding motifs, regardless of circular or linear RNAs. Our researches not only facilitate better understanding of the life history and molecular behavior of circRNA in cell, but also contribute to the exploration for new biological functions of circRNA.
2019-01-16 | GSE107169 | GEO
Project description:Intensive research in past two decades has uncovered the presence and importance of noncoding RNAs (ncRNAs), which includes microRNAs (miRs) and long ncRNAs (lncRNAs). These two classes of ncRNAs interact to a certain extent, as some lncRNAs bind to miRs to sequester them. Such lncRNAs are collectively called 'competing endogenous RNAs' or 'miRNA sponges'. In this study, we screened for lncRNAs that may act as miRNA sponges using the publicly available data sets and databases. To uncover the roles of miRNA sponges, loss-of-function experiments were conducted, which revealed the biological roles as miRNA sponges. LINC00324 is important for the cell survival by binding to miR-615-5p leading to the de-repression of its target BTG2 LOC400043 controls several biological functions via sequestering miR-28-3p and miR-96-5p, thereby changing the expressions of transcriptional regulators. Finally, we also screened for circular RNAs (circRNAs) that may function as miRNA sponges. The results were negative at least for the selected circRNAs in this study. In conclusion, miRNA sponges can be identified by applying a series of bioinformatics techniques and validated with biological experiments. The expressions of miRs were examined in HEK-293 cells that were LINC00324- or LOC400043-silenced using siRNA.
2016-07-06 | E-GEOD-73689 | biostudies-arrayexpress
Project description:Intensive research in past two decades has uncovered the presence and importance of noncoding RNAs (ncRNAs), which includes microRNAs (miRs) and long ncRNAs (lncRNAs). These two classes of ncRNAs interact to a certain extent, as some lncRNAs bind to miRs to sequester them. Such lncRNAs are collectively called 'competing endogenous RNAs' or 'miRNA sponges'. In this study, we screened for lncRNAs that may act as miRNA sponges using the publicly available data sets and databases. To uncover the roles of miRNA sponges, loss-of-function experiments were conducted, which revealed the biological roles as miRNA sponges. LINC00324 is important for the cell survival by binding to miR-615-5p leading to the de-repression of its target BTG2 LOC400043 controls several biological functions via sequestering miR-28-3p and miR-96-5p, thereby changing the expressions of transcriptional regulators. Finally, we also screened for circular RNAs (circRNAs) that may function as miRNA sponges. The results were negative at least for the selected circRNAs in this study. In conclusion, miRNA sponges can be identified by applying a series of bioinformatics techniques and validated with biological experiments. The expressions of miRs were examined in HEK-293, HUVEC and Hs68 cells.
2016-07-06 | E-GEOD-73690 | biostudies-arrayexpress