Mutant U2AF1-Induced Alternative Splicing of H2afy (macroH2A1) Regulates B-Lymphopoiesis in Mice
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ABSTRACT:
PROVIDER: PRJNA515274 | ENA |
REPOSITORIES: ENA
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Project description:Acquired spliceosome gene mutations are among the most common genetic alterations in myelodysplastic syndromes (MDS). Here we present evidence that H2AFY(macroH2A1), a histone H2A variant, is a functional target that is alternatively spliced by mutant U2AF1(S34F), a spliceosome gene. Expression of H2AFY1.1, a H2AFY splice-isoform that is reduced by U2AF1(S34F) expression, rescues the reduction in B-cells observed in U2AF1(S34F) mice. Human MDS samples with U2AF1 mutations have a similar reduction in B-cells. Collectively, our data suggest that altered splicing of H2AFY contributes to MDS pathogenesis.
2021-08-31 | GSE125118 | GEO
Project description: Not available
| S-EPMC8454217 | biostudies-literature
Project description:The splicing factor gene, U2AF1, is recurrently mutated in a variety of human cancers, including lung adenocarcinomas. The most frequent U2AF1 mutant, U2AF1 p.Ser34Phe (S34F), induces specific changes in pre-mRNA splicing, but it is unclear how these splicing changes are regulated. We have used genomic editing methods to modify the U2AF1 gene locus in an immortalized human bronchial epithelial cell line (HBEC3kt) and in human lung adenocarcinoma cells with pre-existing U2AF1 alleles, creating a U2AF1 S34F allele in the endogenous locus of HBEC3kts and inactivating U2AF1 S34F alleles in two lung adenocarcinoma cell lines (H441 and HCC78). By comparing global splicing alterations in these isogenic pairs of cell lines, we have identified many splicing alterations that are associated with the U2AF1 S34F mutation. Further, by decreasing the levels of wild-type U2AF1 in the isogenic HBEC3kt cells, we show that the magnitude of mutant-associated splicing is proportional to the ratio of S34F:WT gene products. This observation suggest that wild-type U2AF1 is a negative regulator of splicing alterations induced by U2AF1 S34F.
2016-09-30 | GSE80136 | GEO
Project description:R-loops and guanine quadruplexes (G4s) are secondary structures of nucleic acids that are ubiquitously present in cells, and are enriched in promoter regions of genes. By employing a bioinformatic approach based on overlap analysis of transcription factor ChIP-seq datasets, we found that many splicing factors, including U2AF1 whose recognition of 3¢ splicing site is crucial for pre-mRNA splicing, exhibit pronounced enrichment at endogenous R-loop- and DNA G4-structure loci in promoter regions of human genes. We revealed that U2AF1 can bind directly to R-loops and DNA G4 structures at low nM binding affinity. Additionally, we showed the ability of U2AF1 to undergo phase separation, which could be stimulated by binding with R-loops, but not duplex DNA, RNA/DNA hybrid, DNA G4, or single-stranded RNA. We also demonstrated that U2AF1 binds to promoter R-loops in human cells, and this binding competes with U2AF1’s interaction with 3¢-splicing site, thereby modulating pre-mRNA splicing. Together, we uncovered a group of candidate proteins that can bind to both R-loops and DNA G4s, revealed the direct and strong interaction of U2AF1 with these nucleic acid structures, and unveiled new functions of this interaction, i.e., promotion of phase separation of U2AF1 and modulation of mRNA splicing. Our work also established, for the first time, a biochemical basis for U2AF1’s occupancy in gene promoters.
2023-10-12 | GSE230254 | GEO
Project description:Whole-exome sequencing studies have identified common mutations affecting genes encoding components of the RNA splicing machinery in hematological malignancies. Here, we sought to determine how mutations affecting the 3' splice site recognition factor U2AF1 altered its normal role in RNA splicing. We find that U2AF1 mutations influence the similarity of splicing programs in leukemias, but do not give rise to widespread splicing failure. U2AF1 mutations cause differential splicing of hundreds of genes, affecting biological pathways implicated in myeloid disease such as DNA methylation (DNMT3B), X chromosome inactivation (H2AFY), the DNA damage response (ATR, FANCA), and apoptosis (CASP8). We show that U2AF1 mutations alter the preferred 3' splice site motif in vivo, in cell culture, and in vitro. Mutations affecting the first and second zinc fingers give rise to different alterations in splice site preference and largely distinct downstream splicing programs. These allele-specific effects are consistent with a computationally predicted model of U2AF1 in complex with RNA. Our findings suggest that U2AF1 mutations contribute to pathogenesis by causing quantitative changes in splicing that affect diverse cellular pathways, and give insight into the normal function of U2AF1’s zinc finger domains. mRNA profiles of K562 cells expressing U2AF1 WT, mutants and knockdown of U2AF1 generated by deep sequencing.
2014-09-23 | E-GEOD-58871 | biostudies-arrayexpress
Project description:Splicing factor mutations are common among cancers, recently emerging as drivers of myeloid malignancies. U2AF1 carries hotspot mutations in its RNA binding motifs; yet how they affect splicing and promote cancer remains unclear. The U2AF1/U2AF2 heterodimer is critical for 3’ splice site (3’SS) definition. To specifically unmask changes in U2AF1 function in vivo, we developed a crosslinking and immunoprecipitation procedure detecting contacts between U2AF1 and the 3’SS AG at single-nucleotide resolution (fractionated eCLIP-seq or freCLIP-seq). Our data reveal that U2AF1 S34F and Q157R mutants establish new 3’SS contacts at -3 and +1 nucleotides, respectively. These effects compromise U2AF2-RNA interactions, resulting predominantly in intron retention and exon exclusion. Integrating RNA binding (eCLIP-seq and freCLIP-seq), splicing (RNA-seq) and turnover (TimeLapse-seq or TL-seq) data, we predicted that U2AF1 mutations directly affect stress granule components. Remarkably, U2AF1-mutant cell lines and patient-derived MDS/AML blasts displayed a heightened stress granule response, pointing to a novel role for biomolecular condensates in adaptive oncogenic strategies. Keywords: splicing, RNA binding, U2AF1, U2AF2, S34F, Q157R, hotspot mutations, 3'SS, 3' splice site, myeloid malignancies, eCLIP, freCLIP, RNA-seq, RNA turnover, TimeLapse-seq, TL-seq, RNA granules, stress granules, stress response, biomolecular condensates, MDS, AML
2022-03-17 | GSE195620 | GEO
Project description:In order to measure the impact of U2AF1 on co-transcriptional splicing, we treated HeLa cells with control siRNA or U2AF1 siRNA. To measure co-transcriptional splicing, we fractionated HeLa cells into cytosolic (Cyt), nucleoplasm (NP), and chromatin/particle (Chr) fractions. We purified total RNA from Chr compartment, spiked in with in vitro transcribed EGFP and FireFly luciferase RNA for data normalization, depleted ribosomal RNAs, and constructed two independent libraries for RNA-seq.
2023-05-27 | GSE175671 | GEO
Project description:Whole-exome sequencing studies have identified common mutations affecting genes encoding components of the RNA splicing machinery in hematological malignancies. Here, we sought to determine how mutations affecting the 3' splice site recognition factor U2AF1 altered its normal role in RNA splicing. We find that U2AF1 mutations influence the similarity of splicing programs in leukemias, but do not give rise to widespread splicing failure. U2AF1 mutations cause differential splicing of hundreds of genes, affecting biological pathways implicated in myeloid disease such as DNA methylation (DNMT3B), X chromosome inactivation (H2AFY), the DNA damage response (ATR, FANCA), and apoptosis (CASP8). We show that U2AF1 mutations alter the preferred 3' splice site motif in vivo, in cell culture, and in vitro. Mutations affecting the first and second zinc fingers give rise to different alterations in splice site preference and largely distinct downstream splicing programs. These allele-specific effects are consistent with a computationally predicted model of U2AF1 in complex with RNA. Our findings suggest that U2AF1 mutations contribute to pathogenesis by causing quantitative changes in splicing that affect diverse cellular pathways, and give insight into the normal function of U2AF1’s zinc finger domains.
2014-09-23 | GSE58871 | GEO
Project description:Mutations of the splicing factor U2AF1 are frequent in the myeloid malignancy myelodysplastic syndromes (MDS) and in other cancers. Patients with MDS suffer from peripheral blood cytopenias, including anemia, and increasing bone marrow blasts. We investigated the impact of the common U2AF1 S34F mutation on cellular function and mRNA splicing in the main cell lineages affected in MDS. We demonstrated that U2AF1 S34F expression in human hematopoietic progenitors impairs erythroid differentiation, and skews granulomonocytic differentiation towards granulocytes. RNA-sequencing of erythroid and granulomonocytic colonies revealed that U2AF1 S34F induced a higher number of cassette exon splicing events in granulomonocytic than erythroid cells, and altered mRNA splicing of many transcripts (expressed in both cell types) in a lineage-specific manner. The introduction of isoform changes identified in the target genes H2AFY and STRAP into hematopoietic progenitors recapitulated phenotypes associated with U2AF1 S34F expression in erythroid and/or granulomonocytic cells, suggesting a causal link. Importantly, we provided evidence showing that isoform modulation of the U2AF1 S34F target genes H2AFY and STRAP rescues the erythroid differentiation defect in U2AF1 S34F MDS cells, raising the possibility of using splicing modulators therapeutically. These data have critical implications for understanding MDS phenotypic heterogeneity, and for the development of new targeted therapies.
2017-04-25 | GSE94153 | GEO
Project description:Mutations in the splicing factor gene U2AF1 have been found in the bone marrow of patients with myelodysplastic syndrome and acute myeloid leukemia, as well as in other cancers. To study the effects of mutant U2AF1(S34F) expression on hematopoiesis and pre-mRNA splicing in hematopoietic cells, we generated two inducible transgenic mouse lines expressing either mutant U2AF1(S34F) or U2AF1(wildtype, WT) as control. We performed strand-specific transcriptome sequencing on bone marrow common myeloid progenitor cells from U2AF1(S34F) and U2AF1(WT)-expressing mice to examine the pre-mRNA splicing changes associated with expression of mutant U2AF1(S34F). Donor-derived common myeloid progenitor cells from mice transplanted with U2AF1(S34F)/rtTA or U2AF1(WT)/rtTA bone marrow were sorted by flow cytometry, and RNA was extracted for transcriptome analysis. Ribosomal RNA was depleted prior to strand-specific RNA sequencing (TruSeq stranded library production, followed by 2 x 100bp paired-end sequencing performed on the HiSeq2000 platform from Illumina). Three samples were sequenced per genotype (n=3), and each sample was composed of bone marrow from 4-5 mice pooled. Reads were aligned to the mouse mm9 reference genome using TopHat (version 2.0.8), and we performed all subsequent analyses in R.
2015-05-11 | E-GEOD-66793 | biostudies-arrayexpress