Similar Datasets
Project description:This project looks into how U1 snRNP inhibition causes a loss of telescripting through premature cleavage and polyadenylation based on the size and function of human genes.
2017-10-02 | GSE103252 | GEO
Project description:Stimulated cells and cancer cells have widespread shortening of mRNA 3'-untranslated regions (3'UTRs) and switches to shorter mRNA isoforms due to usage of more proximal polyadenylation signals (PASs) in introns and last exons. U1 snRNP (U1), vertebrates' most abundant non-coding (spliceosomal) small nuclear RNA, silences proximal PASs and its inhibition with antisense morpholino oligonucleotides (U1 AMO) triggers widespread premature transcription termination and mRNA shortening. Here we show that low U1 AMO doses increase cancer cells' migration and invasion in vitro by up to 500%, whereas U1 over-expression has the opposite effect. In addition to 3'UTR length, numerous transcriptome changes that could contribute to this phenotype are observed, including alternative splicing, and mRNA expression levels of proto-oncogenes and tumor suppressors. These findings reveal an unexpected role for U1 homeostasis (available U1 relative to transcription) in oncogenic and activated cell states, and suggest U1 as a potential target for their modulation.
| S-EPMC6946686 | biostudies-literature
Project description:U1 snRNP regulates cancer cell migration and invasion in vitro
| PRJNA590153 | ENA
Project description:The DNA damage response (DDR) involves coordinated control of gene expression and DNA repair. Using deep sequencing we found widespread changes of alternative cleavage and polyadenylation (APA) site usage upon UV-treatment in mammalian cells. APA regulation in the 3’ untranslated region (3’UTR) is substantial, leading to both shortening and lengthening of 3’UTRs. Interestingly, a strong activation of intronic APA sites is detected, resulting in widespread expression of truncated transcripts. Intronic APA events are biased to the 5’ end of genes and affect gene groups with important functions in DDR. Moreover, intronic APA site activation during DDR correlates with a decrease in U1 snRNA levels, and this is reversed by U1 snRNA overexpression. Importantly, U1 snRNA overexpression decreases UV-induced apoptosis. Together, these studies describe a significant gene regulatory scheme in DDR where U1 snRNP impacts gene expression via APA.
2016-05-01 | GSE71801 | GEO
Project description:Pervasive transcription in the mammalian genome produces thousands of long noncoding RNAs (lncRNAs) and promoter- or enhancer-associated unstable transcripts. They preferentially locate to chromatin, at which some regulate chromatin structure, transcription and RNA processing. While several RNA sequences responsible for nuclear localization have been identified, such as repeats in the lncRNA Xist and Alu-like elements for long RNAs, how lncRNAs as a class are enriched on chromatin remains elusive. To screen for cis-elements that contribute to RNA-chromatin localization, we developed a high-throughput method named RNA elements for subcellular localization by sequencing (REL-seq), and discovered a U1 small nuclear ribonucleoprotein (snRNP)-recognition motif being critical for chromatin localization of reporter RNAs. Across the genome, chromatin-bound lncRNAs, which are enriched with 5’ splice sites and depleted of 3’ splice sites, exhibit high levels of U1 snRNA binding compared to cytoplasm-localized protein-coding mRNAs. Acute depletion of U1 snRNA, or U1 snRNP protein component SNRNP70, drastically reduces the chromatin association of hundreds of lncRNAs and unstable transcripts without altering the overall transcription rate in cells. In addition, rapid degradation of SNRNP70 reduces the localization of both nascent and polyadenylated lncRNA transcripts to chromatin, and disrupts the nuclear-speckles and genome-wide localization of Malat1, a highly conserved and abundant lncRNA. Moreover, chromatin-bound U1 snRNP interacts with transcriptionally engaged RNA polymerase (Pol) II. Together, these results demonstrate that U1 snRNP acts widely to tether and mobilize lncRNAs to chromatin in a Pol II transcription-dependent manner. Our findings uncover a novel role of U1 snRNP beyond pre-mRNA processing and provide molecular insights into how lncRNAs are recruited to Pol II-transcribed genes and have a propensity for chromatin-associated functions.
2020-01-01 | GSE134287 | GEO
Project description:Transcription of the mammalian genome is pervasive, but productive transcription outside of protein-coding genes is limited by unknown mechanisms. In particular, although RNA polymerase II (RNAPII) initiates divergently from most active gene promoters, productive elongation occurs primarily in the sense-coding direction. Here we show in mouse embryonic stem cells that asymmetric sequence determinants flanking gene transcription start sites control promoter directionality by regulating promoter-proximal cleavage and polyadenylation. We find that upstream antisense RNAs are cleaved and polyadenylated at poly(A) sites (PASs) shortly after initiation. De novo motif analysis shows PAS signals and U1 small nuclear ribonucleoprotein (snRNP) recognition sites to be the most depleted and enriched sequences, respectively, in the sense direction relative to the upstream antisense direction. These U1 snRNP sites and PAS sites are progressively gained and lost, respectively, at the 5' end of coding genes during vertebrate evolution. Functional disruption of U1 snRNP activity results in a dramatic increase in promoter-proximal cleavage events in the sense direction with slight increases in the antisense direction. These data suggest that a U1-PAS axis characterized by low U1 snRNP recognition and a high density of PASs in the upstream antisense region reinforces promoter directionality by promoting early termination in upstream antisense regions, whereas proximal sense PAS signals are suppressed by U1 snRNP. We propose that the U1-PAS axis limits pervasive transcription throughout the genome. 3' end sequencing of poly (A) + RNAs in mouse ES cells with and without U1 snRNP inhibition using antisense morpholino oligonucleotides (AMO). Each with two biological replicates.
2013-06-28 | E-GEOD-46433 | biostudies-arrayexpress
Project description:Individual-nucleotide resolution UV-crosslinking and immunoprecipitation (iCLIP) combined with high-throughput sequencing was performed to generate genome-wide binding maps of two U1-snRNP proteins: U1C and U1-70K in Trypanosoma brucei. 3 (2) biological replicates of U1C (U1-70K) -specific co-immunoprecipitated RNA after UV-crosslinking
2014-05-16 | E-GEOD-43848 | biostudies-arrayexpress
Project description:Full-length transcription in the majority of human genes depends on U1 snRNP (U1) to co-transcriptionally suppress transcription-terminating premature 3’-end cleavage and polyadenylation (PCPA) from cryptic polyadenylation signals (PASs) in introns. However, the mechanism of this U1 activity, termed telescripting, is unknown. Here, we captured a complex, comprising U1 and CPA factors (U1–CPAFs), that binds intronic PASs and suppresses PCPA. U1–CPAFs are distinct from U1-spliceosomal complexes; they include CPA’s three main subunits, CFIm, CPSF, and CstF, lack essential splicing factors, and associate with transcription elongation and mRNA export complexes. Telescripting requires U1:pre-mRNA base-pairing, which can be disrupted by U1 antisense oligonucleotide (U1 AMO), triggering PCPA. U1 AMO remodels U1–CPAFs, revealing changes, including recruitment of CPA-stimulating factors, that explain U1–CPAFs’ switch from repressive to activated states. Our findings outline U1 telescripting mechanism and demonstrate U1’s unique role as central-regulator of pre-mRNA processing and transcription.
2019-07-31 | GSE135140 | GEO
Project description:Alternative pre-mRNA splicing (AS) is a critical regulatory mechanism that operates extensively in the nervous system to produce diverse protein isoforms. Fruitless AS isoforms have been shown to influence male courtship behavior, but the underlying mechanisms are unknown. Using genome-wide approaches and quantitative behavioral assays, we show that the P element somatic inhibitor (PSI) and its interaction with U1 snRNP control male courtship behavior. PSI mutants lacking the U1 snRNP-interacting domain (PSIΔAB mutant) exhibit extended but futile mating attempts. The PSIΔAB mutant results in significant changes in the AS patterns of ~1,200 genes in the Drosophila brain, many of which have been implicated in the regulation of male courtship behavior. PSI directly regulates the AS of at least a third of these transcripts, suggesting that PSI-U1 snRNP interactions coordinate the behavioral network underlying courtship behavior. Importantly, one of these direct targets is fruitless — the master regulator of courtship. Thus, PSI imposes a specific mode of regulatory control within the neuronal circuit controlling courtship, even though it is broadly expressed in the fly nervous system. This study reinforces the importance of AS in the control of gene activity in neurons and integrated neuronal circuits, and provides a surprising link between a pleiotropic pre-mRNA splicing pathway and the precise control of successful male mating behavior.
2016-04-30 | GSE79916 | GEO
Project description:Synaptic activity induces well-known changes in enhancer-promoter driven gene expression but also induces changes in splicing and polyadenylation that are understudied. Here, we investigate the mechanism of expression for alternative polyadenylation isoform Homer1a, an immediate early gene essential to synaptic plasticity. We report that neuronal activation, in neuronal cultures and in adult mouse brain, depletes the splice factor U1 snRNP from Homer1 pre-mRNA and that this causes shifted utilization of a cryptic polyadenylation signal within intron 5 resulting in Homer1a expression. Because U1 snRNP is a ubiquitous splice factor, we tested the generality of activity-driven U1 snRNP depletion as a mechanism for gene expression using RNA immunoprecipitation sequencing. Analysis reveals that neuronal activity changes U1 snRNP binding to ~2000 transcripts and for a subset of transcripts, a reduction in U1 snRNP binding was accompanied by utilization of a cryptic intronic polyadenylation site. This subset is enriched for transcripts encoding synaptic proteins involved in excitability control. Genes demonstrating activity-dependent reduced U1 snRNP binding often encode a binding motif for Sam68, a neuronal alternative polyadenylation factor. Findings reveal that activity-driven changes in intron utilization for transcript termination serves an important role in synaptic plasticity.
2024-10-08 | GSE185662 | GEO