Free circular introns with an unusual branchpoint in neuronal projections
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ABSTRACT:
ORGANISM(S): Rattus norvegicus
PROVIDER: GSE129924 | GEO | 2019/04/18
REPOSITORIES: GEO
Similar Datasets
Project description:Free circular introns with an unusual branchpoint in neuronal projections
| PRJNA533159 | ENA
Project description:Removal of introns by pre-mRNA splicing is a critical and in some cases rate-limiting step in mammalian gene expression. Deep sequencing of mouse embryonic stem cell RNA revealed many specific internal introns that are significantly more abundant than the other introns within poly(A) selected transcripts; we classify these as “detained” introns (DIs). We identified thousands of DIs flanking both constitutive and alternatively spliced exons in human and mouse cell lines. Drug inhibition of Clk SR-protein kinase activity triggered rapid splicing changes in a specific set of DIs, about half of which showed increased splicing and half increased intron detention, altering the transcript pool of over 300 genes. These data suggest a widespread mechanism by which a nuclear detained pool of mostly processed pre-mRNAs can be rapidly mobilized in response to stress or homeostatic autoregulation. v6.5 mouse embryonic stem cells were untreated, treated with the Clk kinase inhibitor KH-CB19, or treated with DMSO as a negative control. Untreated cells were harvested and a single replicate was sequenced using a custom, ligation-based, stranded library preparation protocol. Treated cells were harvested at time 0 and at 2 hours post-treatment, and poly(A)-selected RNA-seq libraries were made from biological duplicates for each treatment/time, barcoded, and sequenced by strand-specific, paired-end sequencing using the Illumina TruSeq kit.
2015-01-15 | E-GEOD-57231 | biostudies-arrayexpress
Project description:Removal of introns by pre-mRNA splicing is a critical and in some cases rate-limiting step in mammalian gene expression. Deep sequencing of mouse embryonic stem cell RNA revealed many specific internal introns that are significantly more abundant than the other introns within poly(A) selected transcripts; we classify these as “detained” introns (DIs). We identified thousands of DIs flanking both constitutive and alternatively spliced exons in human and mouse cell lines. Drug inhibition of Clk SR-protein kinase activity triggered rapid splicing changes in a specific set of DIs, about half of which showed increased splicing and half increased intron detention, altering the transcript pool of over 300 genes. These data suggest a widespread mechanism by which a nuclear detained pool of mostly processed pre-mRNAs can be rapidly mobilized in response to stress or homeostatic autoregulation.
2015-01-15 | GSE57231 | GEO
Project description:Small nucleolar RNAs (snoRNAs) and small Cajal body-specific RNAs (scaRNAs) are non-coding RNAs involved in the maturation of other RNA molecules and generally located in the introns of host genes. It is now emerging that altered sno/scaRNAs expression may play a pathological role in cancer. This study elucidates the patterns of sno/scaRNAs expression in multiple myeloma (MM), by profiling puri?ed malignant plasma cells from 55 MMs, 8 secondary plasma cell leukemias (sPCL) and 4 normal controls. Overall, a global sno/scaRNAs down-regulation was found in MMs and at more extent in sPCLs compared to normal plasma cells. Whereas SCARNA22 resulted the only sno/scaRNA characterizing the TC4 MM, TC2 group displayed a distinct sno/scaRNA signature overexpressing members of SNORD115 and SNORD116 families located in a region finely regulated by imprinting mechanism at 15q11. However, the imprinting center resulted overall hypomethylated in MMs independently of the SNORD115 and SNORD116 expression levels. Finally, integrative analyses with available gene expression and genome-wide data revealed the occurrence of significant sno/scaRNAs/host genes co-expression and the putative influence of allelic imbalances on specific snoRNAs expression. Our data extend the current view of sno/scaRNAs deregulation in cancer and add novel information into the bio-molecular complexity of plasma cell dyscrasias.
2013-06-25 | GSE39683 | GEO
Project description:We report the effect of splicing upon O-GlcNAc perturbation with OGT inhibitor or OGA inhibitor. We found that splicing is acutely affected through our phosphoproteomics data when cells are treated with OGT inhibitor. By obtaining the various splicing events that are affected by OGT or OGA inhibition, we found that O-GlcNAc is a major regulator of detained introns splicing. At early time point, we observed highly specific splicing of OGT/OGA detained introns to buffer O-GlcNAc changes. At longer time point, ~80% of the total detained introns are affected by O-GlcNAc perturbation, while the rest of canonical splicing events are only minimally affected (~ 5%).
2020-04-03 | GSE138783 | GEO
Project description:Intron retention (IR) is an alternative splicing event where mRNAs containing unspliced introns are exported to the cytoplasm and then either translated, giving rise to new protein isoforms, or degraded via the nonsense-mediated decay pathway. However, unspliced introns are also seen in nuclear RNA. Some of these are spliced at a low rate but do eventually become fully spliced and their respective mRNAs exported, while others stay retained and are recognized by nuclear decay machineries. IR has been shown to be regulated during granulocyte and neuronal differentiation and in some cancers, and a subset of the nuclear retained introns, called detained introns, have been implicated in growth control pathways. Despite many findings on IR and its biological significance, it is still not clear whether an incompletely spliced intron observed is a true retained intron that is exported as an mRNA or is a product of slow splicing that remains in the nucleus. A better understanding is needed of the molecular events that reduce intron excision rate and determine the release of an RNA for export. We have found that some genes in mouse embryonic stem cells (mESCs) produce RNAs that are highly associated with the high molecular-weight nuclear pellet (chromatin), rather than the soluble nucleoplasm or cytoplasm. This chromatin-associated RNA is polyadenylated, usually contains one or more incompletely spliced introns, and is often extensively bound by polypyrimidine tract-binding protein 1 (PTBP1). We hypothesize that PTBP1 inhibits splicing of these introns, and this causes sequestration of the transcript on chromatin. We are studying the role of PTBP1 in inhibiting intron excision and anchoring RNAs in the nuclear and chromatin compartments of mESCs.
2020-11-18 | GSE159993 | GEO
Project description:Small nucleolar RNAs (snoRNAs) and small Cajal body-specific RNAs (scaRNAs) are non-coding RNAs involved in the maturation of other RNA molecules and generally located in the introns of host genes. It is now emerging that altered sno/scaRNAs expression may play a pathological role in cancer. This study elucidates the patterns of sno/scaRNAs expression in multiple myeloma (MM), by profiling puri?ed malignant plasma cells from 55 MMs, 8 secondary plasma cell leukemias (sPCL) and 4 normal controls. Overall, a global sno/scaRNAs down-regulation was found in MMs and at more extent in sPCLs compared to normal plasma cells. Whereas SCARNA22 resulted the only sno/scaRNA characterizing the TC4 MM, TC2 group displayed a distinct sno/scaRNA signature overexpressing members of SNORD115 and SNORD116 families located in a region finely regulated by imprinting mechanism at 15q11. However, the imprinting center resulted overall hypomethylated in MMs independently of the SNORD115 and SNORD116 expression levels. Finally, integrative analyses with available gene expression and genome-wide data revealed the occurrence of significant sno/scaRNAs/host genes co-expression and the putative influence of allelic imbalances on specific snoRNAs expression. Our data extend the current view of sno/scaRNAs deregulation in cancer and add novel information into the bio-molecular complexity of plasma cell dyscrasias. This series of microarray experiments contains the gene expression profiles of purified plasma cells (PCs) obtained from 55 multiple myeloma (MM) and 8 secondary plasma cell leukemia (sPCL) at diagnosis. PCs were purified from bone marrow samples using CD138 immunomagnetic microbeads according to the manufacturer's instructions (MidiMACS system, Miltenyi Biotec); the purity of the positively selected PCs was assessed by morphology and flow cytometry and was > 90% in all cases. 5.5 micrograms of single-stranded DNA target obtained from 100 ng of purified total RNA was fragmented and then labeled using the WT Terminal Labeling Kit according to the standard Affymetrix protocol (GeneChip® Whole Transcript (WT) Sense Target Labeling Assay Manual). The fragmented labeled single-stranded DNA target was hybridized for 16 hours and 30 minutes at 45°C on GeneChip® Gene 1.0 ST array according to the standard Affymetrix protocol. Washing and scanning were performed using GeneChip System of Affymetrix (GeneChip Hybridization Oven 640, GeneChip Fluidics Station 450 and GeneChip Scanner 7G). The raw intensity expression values were processed by Robust Multi-array Average (RMA) complete procedure with the re-mapped Chip Definition Files (CDF) from BrainArray libraries version 15.0.0 available at http://brainarray.mbni.med.umich.edu/Brainarray/Database/CustomCDF/15.0.0/entrezg.asp.
2013-06-25 | E-GEOD-39683 | biostudies-arrayexpress
Project description:The polarized structure of axons and dendrites in neuronal cells depends in part on RNA localization. Previous studies have looked at which polyadenylated RNAs are enriched in neuronal projections or at synapses, but less is known about the distribution of non-adenylated RNAs. By physically dissecting projections from cell bodies of primary rat hippocampal neurons and sequencing total RNA, we found an unexpected set of free circular introns with a non-canonical branchpoint enriched in neuronal projections. These introns appear to be tailless lariats that escape debranching. They lack ribosome occupancy, sequence conservation, and known localization signals, and their function, if any, is not known. Nonetheless, their enrichment in projections has important implications for our understanding of the mechanisms by which RNAs reach distal compartments of asymmetric cells.
| S-EPMC6879206 | biostudies-literature
Project description:Small nucleolar RNAs (snoRNAs) and small Cajal body-specific RNAs are non-coding RNAs involved in the maturation of other RNA molecules. Alterations of sno/scaRNA expression may play a role in cancerogenesis. This study elucidates the patterns of sno/scaRNA expression in highly purified cells from 211 chronic lymphocytic leukemia (CLL) patients (Binet stage A) also in comparison with those of different normal B-cell subsets. CLLs display a sno/scaRNAs expression profile similar to normal memory, naïve and marginal-zone B-cells, with the exception of a few down-regulated transcripts (SNORA31, -6, -62, and -71C). Our analyses also suggest some heterogeneity in the pattern of sno/scaRNAs expression which is apparently unrelated to the major biological (ZAP-70 and CD38), molecular (IGHV mutation) and cytogenetic markers. Moreover, we found that SNORA70F was significantly down-regulated in poor prognostic subgroups and this phenomenon was associated with the down-regulation of its host gene COBLL1. Finally, we generated an independent model based on SNORA74A and SNORD116-18 expression, which appears to distinguish two different prognostic CLL groups. These data extend the view of sno/scaRNAs deregulation in cancer and may contribute to discover novel biomarkers associated with the disease and potentially useful to predict the clinical outcome of early stage CLL patients.
2014-03-24 | GSE46261 | GEO
Project description:Somatic mutations in the spliceosome gene ZRSR2 (located on the X chromosome) are associated with myelodysplastic syndrome (MDS). ZRSR2 is involved in the recognition of 3' splice site during the early stages of spliceosome assembly; however, its precise role in RNA splicing has remained unclear. Here, we characterize ZRSR2 as an essential component of the minor spliceosome (U12-dependent) assembly. shRNA mediated knockdown of ZRSR2 leads to impaired splicing of the U12-type introns, and RNA-Sequencing of MDS bone marrow reveals that loss of ZRSR2 activity causes increased mis-splicing. These splicing defects involve retention of the U12-type introns while splicing of the U2-type introns remain mostly unaffected. ZRSR2 deficient cells also exhibit reduced proliferation potential and distinct alterations in myeloid and erythroid differentiation in vitro. These data identify a specific role for ZRSR2 in RNA splicing and highlight dysregulated splicing of U12-type introns as a characteristic feature of ZRSR2 mutations in MDS. RNA sequencing was performed on 16 bone marrow samples (MDS and normal) and six samples of control or ZRSR2 shRNA transduced TF-1 cells and data was analysed for aberrant splicing caused by ZRSR2 mutations/deficiency.
2015-01-15 | E-GEOD-63816 | biostudies-arrayexpress