Channel Nuclear Pore Complex subunits are required for transposon silencing in Drosophila
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE152297 | GEO | 2021/04/15
REPOSITORIES: GEO
Similar Datasets
Project description:The piRNA pathway is a small RNA-based immune system that silences mobile genetic elements in animal germlines. In Drosophila ovaries, piRNAs are produced from discrete genomic loci, called piRNA clusters, which are composed of inactive transposon copies and fragments and thus constitute a genetically encoded memory of past transposon challenges. Two types of piRNA clusters exist in flies: dual-strand clusters, expressed only in the germline via a highly specialised machinery, and uni-strand cluster, which are predominantly expressed in the somatic follicle cells. Flamenco (flam) is the major uni-strand piRNA cluster in Drosophila, giving rise to the majority of somatic piRNAs. Flam resembles a canonical RNA polymerase II transcriptional unit, nonetheless it can be specifically recognised by the piRNA pathway and directed to the biogenesis machinery. Recent work has implicated the RNA helicase Yb in the licensing of somatic piRNA production, however a detailed understanding of the molecular mechanisms underlying flam export and specification is still lacking. Here, we show that flam export triggers the assembly of peri-nuclear condensates of Yb and provide evidence that piRNA production from flam specifically requires subunits of the Nuclear Pore Complex (NPC). In the absence of some NPC subunits, transposons become de-silenced and piRNA biogenesis is compromised exclusively from flam. We also show that Yb transiently associates with the NPC to promote flam export. Taken together, our data shed light on how the export of uni-strand cluster transcripts is achieved and suggest the evolution of a specialised machinery that couples transcription, nuclear export and piRNA production.
2021-04-16 | PXD019671 | Pride
Project description:The piRNA pathway is a small RNA-based immune system that silences mobile genetic elements in animal germlines. In Drosophila ovaries, piRNAs are produced from discrete genomic loci, called piRNA clusters, which are composed of inactive transposon copies and fragments and thus constitute a genetically encoded memory of past transposon challenges. Two types of piRNA clusters exist in flies: dual-strand clusters, expressed only in the germline via a highly specialised machinery, and uni-strand cluster, which are predominantly expressed in the somatic follicle cells. Flamenco (flam) is the major uni-strand piRNA cluster in Drosophila, giving rise to the majority of somatic piRNAs. Flam resembles a canonical RNA polymerase II transcriptional unit, nonetheless it can be specifically recognised by the piRNA pathway and directed to the biogenesis machinery. Recent work has implicated the RNA helicase Yb in the licensing of somatic piRNA production, however a detailed understanding of the molecular mechanisms underlying flam export and specification is still lacking. Here, we show that flam export triggers the assembly of peri-nuclear condensates of Yb and provide evidence that piRNA production from flam specifically requires subunits of the Nuclear Pore Complex (NPC). In the absence of some NPC subunits, transposons become de-silenced and piRNA biogenesis is compromised exclusively from flam. We also show that Yb transiently associates with the NPC to promote flam export. Taken together, our data shed light on how the export of uni-strand cluster transcripts is achieved and suggest the evolution of a specialised machinery that couples transcription, nuclear export and piRNA production.
2021-04-15 | PXD019670 | Pride
Project description:The piRNA pathway is a small RNA-based immune system that silences mobile genetic elements in animal germlines. In Drosophila ovaries, piRNAs are produced from discrete genomic loci, called piRNA clusters, which are composed of inactive transposon copies and fragments and thus constitute a genetically encoded memory of past transposon challenges. Two types of piRNA clusters exist in flies: dual-strand clusters, expressed only in the germline via a highly specialised machinery, and uni-strand cluster, which are predominantly expressed in the somatic follicle cells. Flamenco (flam) is the major uni-strand piRNA cluster in Drosophila, giving rise to the majority of somatic piRNAs. Flam resembles a canonical RNA polymerase II transcriptional unit, nonetheless it can be specifically recognised by the piRNA pathway and directed to the biogenesis machinery. Recent work has implicated the RNA helicase Yb in the licensing of somatic piRNA production, however a detailed understanding of the molecular mechanisms underlying flam export and specification is still lacking. Here, we show that flam export triggers the assembly of peri-nuclear condensates of Yb and provide evidence that piRNA production from flam specifically requires subunits of the Nuclear Pore Complex (NPC). In the absence of some NPC subunits, transposons become de-silenced and piRNA biogenesis is compromised exclusively from flam. We also show that Yb transiently associates with the NPC to promote flam export. Taken together, our data shed light on how the export of uni-strand cluster transcripts is achieved and suggest the evolution of a specialised machinery that couples transcription, nuclear export and piRNA production.
2021-07-02 | PXD019674 | Pride
Project description:Channel Nuclear Pore Complex subunits are required for transposon silencing in Drosophila
| PRJNA638919 | ENA
Project description:The repression of transposons by the Piwi-interacting RNA (piRNA) pathway is essential to protect animal germ cells. In Drosophila ovaries, Panoramix (Panx) enforces transcriptional silencing by binding to the target-engaged Piwi-piRNA complex, although the precise mechanisms by which this occurs remain elusive. Here, we show that Panx functions together with a germline specific paralogue of a nuclear export factor, dNxf2, and its cofactor dNxt1 (p15), as a ternary complex to suppress transposon expression. Similar to Panx, dNxf2 is essential for animal fertility. Structural and functional analyses demonstrate that dNxf2 binds Panx via its UBA domain, which plays an important role in transposon silencing. Unexpectedly, dNxf2 interacts directly with dNxf1 (TAP), a general nuclear export factor. As a result, dNxf2 prevents dNxf1 from binding to the FG repeats of the nuclear pore complex, a process required for proper RNA export. Transient tethering of dNxf2 to nascent transcripts leads to their nuclear retention. Thus, dNxf2 functions in a Pandas (Panoramix dNxf2 dependent TAP/p15 silencing) complex, which counteracts the canonical RNA exporting machinery and restricts transposons to the nuclear peripheries. Our findings may have broader implications for understanding how RNA metabolism regulates epigenetic gene silencing and heterochromatin formation.
2019-08-06 | PXD014926 |
Project description:The nuclear pore complex (NPC) is the principal gateway between nucleus and cytoplasm that enables exchange of macromolecular cargo. Composed of multiple copies of ~30 different nucleoporins (Nups), the NPC acts as a selective portal, interacting with factors which individually license passage of specific cargo classes. Here we show that two Nups of the inner channel, Nup54 and Nup58, are essential for transposon silencing via the PIWI-interacting RNA (piRNA) pathway in the Drosophila ovary. In ovarian follicle cells, loss of Nup54 and Nup58 results in compromised piRNA biogenesis exclusively from the flamenco locus, whereas knockdowns of other NPC subunits have widespread consequences. This provides evidence that some Nups can acquire specialised roles in tissue-specific contexts. Our findings consolidate the idea that the NPC has functions beyond simply constituting a barrier to nuclear/cytoplasmic exchange as genomic loci subjected to strong selective pressure can exploit NPC subunits to facilitate their expression.
| S-EPMC8133776 | biostudies-literature
Project description:The transposon silencing piRNAs are produced from precursors that are encoded by heterochromatic clusters and processed in the perinuclear nuage. We show that the Drosophila nuclear DEAD box protein UAP56, previously implicated in mRNA splicing and nuclear export, co-localizes with the cluster-associated HP1 homologue Rhino. Prominent nuclear foci containing Rhi and UAP56 localize directly across the nuclear envelope from Vasa, a conserved DEAD box protein and core nuage component that is required for piRNA production, and piRNA precursors immunoprecipitate with both UAP56 and Vasa. A uap56 point mutation that prevents UAP56 protein co-localization with Rhino also disrupts nuage organization, transposon silencing, and expression of dual strand piRNA clusters. By contrast, this allele significantly increases ectopic piRNAs from protein coding genes. We therefore propose that UAP56 and Vasa organize a piRNA-processing compartment that spans the nuclear envelope, increasing the efficiency and specificity of piRNA biogenesis. 3 replicates of each sample (uap56, vasa), total RNA samples hybridized to tiling array.
2012-11-28 | E-GEOD-35636 | biostudies-arrayexpress
Project description:The transposon silencing piRNAs are produced from precursors that are encoded by heterochromatic clusters and processed in the perinuclear nuage. We show that the Drosophila nuclear DEAD box protein UAP56, previously implicated in mRNA splicing and nuclear export, co-localizes with the cluster-associated HP1 homologue Rhino. Prominent nuclear foci containing Rhi and UAP56 localize directly across the nuclear envelope from Vasa, a conserved DEAD box protein and core nuage component that is required for piRNA production, and piRNA precursors immunoprecipitate with both UAP56 and Vasa. A uap56 point mutation that prevents UAP56 protein co-localization with Rhino also disrupts nuage organization, transposon silencing, and expression of dual strand piRNA clusters. By contrast, this allele significantly increases ectopic piRNAs from protein coding genes. We therefore propose that UAP56 and Vasa organize a piRNA-processing compartment that spans the nuclear envelope, increasing the efficiency and specificity of piRNA biogenesis. RNA-Seq: 3 samples examined: w1118, uap56 mutant un-oxidized, uap56 mutant oxidized RIP-Seq: 6 samples: UAP56-Venus, sz-Venus, and wild type w1 with anti-flag and input control each.
2012-11-28 | E-GEOD-35637 | biostudies-arrayexpress
Project description:Master transcription factors such as TP63 establish super-enhancers (SEs) to drive core transcriptional networks in cancer cells, yet the spatiotemporal regulation of SEs within the nucleus remains unknown. The nuclear pore complex (NPC) may tether SEs to the nuclear pore where RNA export rates are maximal. Here, we report that NUP153, a component of the NPC, anchors SEs to the NPC and enhances TP63 expression by maximizing mRNA export. This anchoring is mediated through protein-protein interaction between the intrinsically disordered regions (IDRs) of NUP153 and the coactivator BRD4. Silencing of NUP153 excludes SEs from the nuclear periphery, decreases TP63 expression, impairs cellular growth, and induces epidermal differentiation of squamous cell carcinoma. Overall, this work reveals the critical roles of NUP153 IDRs in the regulation of SE localization, thus providing insights into a new layer of gene regulation at the epigenomic and spatial level.
2023-12-23 | GSE169295 | GEO
Project description:The transposon silencing piRNAs are produced from precursors that are encoded by heterochromatic clusters and processed in the perinuclear nuage. We show that the Drosophila nuclear DEAD box protein UAP56, previously implicated in mRNA splicing and nuclear export, co-localizes with the cluster-associated HP1 homologue Rhino. Prominent nuclear foci containing Rhi and UAP56 localize directly across the nuclear envelope from Vasa, a conserved DEAD box protein and core nuage component that is required for piRNA production, and piRNA precursors immunoprecipitate with both UAP56 and Vasa. A uap56 point mutation that prevents UAP56 protein co-localization with Rhino also disrupts nuage organization, transposon silencing, and expression of dual strand piRNA clusters. By contrast, this allele significantly increases ectopic piRNAs from protein coding genes. We therefore propose that UAP56 and Vasa organize a piRNA-processing compartment that spans the nuclear envelope, increasing the efficiency and specificity of piRNA biogenesis.
2012-11-28 | GSE35636 | GEO