P53 ablation fails to completely rescue microcephaly caused by impaired minor intron splicing
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ABSTRACT:
PROVIDER: PRJNA707040 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR13866584_1.fastq.gz | Fastqsanger.gz | |||
| SRR13866584_2.fastq.gz | Fastqsanger.gz | |||
| SRR13866585_1.fastq.gz | Fastqsanger.gz | |||
| SRR13866585_2.fastq.gz | Fastqsanger.gz | |||
| SRR13866586_1.fastq.gz | Fastqsanger.gz |
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Project description:Mutations in the minor spliceosome components such as RNU4atac, a small nuclear RNA (snRNA), are linked to primary microcephaly. We have reported that in the conditional knockout (cKO) mice for Rnu11, a minor spliceosome snRNA, minor intron splicing defect in minor intron-containing genes (MIGs) regulating cell cycle resulted in cell cycle defect with a concomitant increase in yH2aX+ cells and P53-mediated apoptosis. Trp53 ablation in the Rnu11 cKO mice did not prevent microcephaly. Although RNAseq analysis of the double knockout (dKO) pallium reflected transcriptomic shift towards the control from the cKO. We found elevated minor intron retention and alternative splicing across minor introns in the dKO. Disruption of these minor intron-containing genes (MIGs) resulted in cell cycle defect that was detected earlier and was more severe in the dKO, but with delayed detection of yH2aX+ DNA damage. Thus, P53 might also play a role in causing DNA damage in the developing pallium. In all, our findings further refine our understanding of the role of the minor spliceosome in cortical development and identify MIGs underpinning microcephaly in minor spliceosome-related disease.
2021-09-30 | GSE168366 | GEO
Project description:Inactivation of the minor spliceosome has been linked to microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1). To interrogate how minor intron splicing regulates cortical development, we employed Emx1-Cre to ablate Rnu11, which encodes the minor spliceosome-specific U11 small nuclear RNA (snRNA), in the developing cortex (pallium). Rnu11 cKO mice were born with microcephaly, caused by death of self-amplifying radial glial cells (RGCs). However, both intermediate progenitor cells (IPCs) and neurons were produced in the U11-null pallium. RNAseq of the pallium revealed elevated minor intron retention in the mutant, particularly in genes regulating cell cycle. Moreover, the only downregulated minor intron-containing gene (MIG) was Spc24, which regulates kinetochore assembly. These findings were consistent with the observation of fewer RGCs entering cytokinesis prior to RGC loss, underscoring the requirement of minor splicing for cell cycle progression in RGCs. Overall, we provide a potential explanation of how disruption of minor splicing might cause microcephaly in MOPD1.
2018-06-05 | GSE96616 | GEO
Project description:Minor spliceosome inhibition due to mutations in RNU4ATAC are linked to primary microcephaly. Ablation of Rnu11, which encodes a minor spliceosome snRNA, inhibits the minor spliceosome in the developing mouse pallium, causing microcephaly. There, cell cycle defects and p53-mediated apoptosis in response to DNA damage resulted in loss of radial glial cells (RGCs), underpinning microcephaly. Here, we ablated Trp53 to block cell death in Rnu11 cKO mice. We report that Trp53 ablation failed to prevent microcephaly in these double knockout (dKO) mice. We show that the transcriptome of the dKO pallium was more similar to the control compared with the Rnu11 cKO. We find aberrant minor intron splicing in minor intron-containing genes involved in cell cycle regulation, resulting in more severely impaired mitotic progression and cell cycle lengthening of RGCs in the dKO that was detected earlier than in the Rnu11 cKO. Furthermore, we discover a potential role of p53 in causing DNA damage in the developing pallium, as detection of γH2aX+ was delayed in the dKO. Thus, we postulate that microcephaly in minor spliceosome-related diseases is primarily caused by cell cycle defects.
| S-EPMC8572008 | biostudies-literature
Project description:Most eukaryotes harbor two distinct pre-mRNA splicing machineries: the major spliceosome, which removes >99% of introns, and the minor spliceosome, which removes rare, evolutionarily conserved introns. Although hypothesized to serve important regulatory functions, physiologic roles for the minor spliceosome are not well understood. For example, the minor spliceosome component ZRSR2 is subject to recurrent, leukemia-associated mutations, yet functional connections between minor introns, hematopoiesis, and cancers are unclear. Here, we identify that impaired minor intron excision via ZRSR2 loss enhances hematopoietic stem cell self-renewal. CRISPR screens mimicking nonsense-mediated decay of minor intron-containing mRNAs converged on LZTR1, a regulator of Ras-related GTPases. LZTR1 minor intron retention was also discovered in the RASopathy Noonan syndrome, due to intronic mutations disrupting splicing, and diverse solid tumors. These data uncover minor intron recognition as a regulator of hematopoiesis, noncoding mutations within minor introns as cancer drivers, and links between ZRSR2 mutations, LZTR1 regulation, and leukemias.
2021-02-09 | GSE149455 | GEO
Project description:Most metazoans contain two distinct pre-mRNA splicing machineries: the major spliceosome, which removes >99% of introns, and the minor spliceosome, which recognizes <1% of introns. Despite their rarity, minor introns are exquisitely conserved amongst species, suggesting important regulatory functions. However, physiologic roles for the minor spliceosome and the relevance of recurrent, leukemia-associated mutations affecting minor spliceosome components are not well understood. Here, we identify that mutational loss of the minor spliceosomal factor ZRSR2 enhances hematopoietic stem cell self-renewal via impaired minor intron splicing that converges on LZTR1, a regulator of Ras-related GTPases. LZTR1 minor intron retention is additionally observed in Noonan syndrome and diverse cancers. These data uncover minor intron recognition as a regulator of hematopoiesis and mechanistic links between ZRSR2 mutations, LZTR1, and leukemia.
2020-11-26 | GSE162136 | GEO
Project description:Minor intron-containing genes (MIGs) are crucial cell cycle regulators and are essential for cell survival. Thus, we explored whether MIGs play a role in cancer progression and cancer therapy resistance. Here we show that MIG-expression segregates sensitive and resistant prostate cancer cells from each other and them from benign tissue. Moreover, the rate of minor intron splicing, a crucial regulatory node for MIG-expression, was more efficient in patients with advanced prostate cancer. We show that the increased minor spliceosome (MiS) activity is downstream of the androgen receptor signaling axis in both therapy sensitive and insensitive prostate cancer types. The increased MiS activity was in line with the elevated expression of U6atac snRNA, a crucial MiS component. We propose the expression of U6atac as a potential point of vulnerability in cancer. MIGs are uniquely susceptible to the MiS, so we used siRNA against U6atac, which like protein-coding transcripts, is downregulated. Inhibition of MiS was sufficient to lower the tumor burden significantly in therapy-resistant (prostate) cancer cells and PCa patient-derived organoids. KD cells displayed elevated minor intron retention and alternative splicing across minor introns of MIGs which enriched for MAPK activity, DNA repair and cell cycle regulation. Importantly, these findings were confirmed by MassSpec analysis. Collectively our study nominates the MiS as a driver of highly proliferative, rapidly dividing (prostate) cancer cells that bears strong potential as a therapeutic target for many different cancer types.
2023-06-08 | PXD026949 | Pride
Project description:Intron evolution in Saccharomycetaceae
| PRJNA253808 | ENA
Project description:BackgroundMutations in minor spliceosome components such as U12 snRNA (cerebellar ataxia) and U4atac snRNA (microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1)) result in tissue-specific symptoms. Given that the minor spliceosome is ubiquitously expressed, we hypothesized that these restricted phenotypes might be caused by the tissue-specific regulation of the minor spliceosome targets, i.e. minor intron-containing genes (MIGs). The current model of inefficient splicing is thought to apply to the regulation of the ~ 500 MIGs identified in the U12DB. However this database was created more than 10 years ago. Therefore, we first wanted to revisit the classification of minor introns in light of the most recent reference genome. We then sought to address specificity of MIG expression, minor intron retention, and alternative splicing (AS) across mouse and human tissues.ResultsWe employed position-weight matrices to obtain a comprehensive updated list of minor introns, consisting of 722 mouse and 770 human minor introns. These can be found in the Minor Intron DataBase (MIDB). Besides identification of 99% of the minor introns found in the U12DB, we also discovered ~ 150 new MIGs. We then analyzed the RNAseq data from eleven different mouse tissues, which revealed tissue-specific MIG expression and minor intron retention. Additionally, many minor introns were efficiently spliced compared to their flanking major introns. Finally, we identified several novel AS events across minor introns in both mouse and human, which were also tissue-dependent. Bioinformatics analysis revealed that several of the AS events could result in the production of novel tissue-specific proteins. Moreover, like the major introns, we found that these AS events were more prevalent in long minor introns, while retention was favoured in shorter introns.ConclusionHere we show that minor intron splicing and AS across minor introns is a highly organised process that might be regulated in coordination with the major spliceosome in a tissue-specific manner. We have provided a framework to further study the impact of the minor spliceosome and the regulation of MIG expression. These findings may shed light on the mechanism underlying tissue-specific phenotypes in diseases associated with minor spliceosome inactivation. MIDB can be accessed at https://midb.pnb.uconn.edu .
| S-EPMC6717393 | biostudies-literature
Project description:Genome-wide DNA methylation profiling of over 850,000 methylation sites carried out using the Illumina MethylationEPIC BeadChip was used to compare 18 babies born with congenital Zika virus microcephaly, 7 babies exposed to Zika virus in utero but born without clinical signs, and 20 control unexposed unaffected babies
2020-07-20 | GSE145233 | GEO
Project description:Minor intron retention drives clonal hematopoietic disorders and diverse cancer predisposition
| PRJNA628709 | ENA