Bombyx mori strain:p50
Ontology highlight
ABSTRACT:
PROVIDER: PRJDB18905 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Competition between adjacent piRNA-producing sites autonomously shapes the repertoire and biogenesis efficiency of piRNAs
| PRJDB17076 | ENA
Project description:PIWI-interacting RNAs (piRNAs) are germline-enriched small RNAs that control transposons to maintain genome integrity1,2,3. To achieve this, piRNAs bind PIWI proteins upon being processed from piRNA precursors1,2,3. Bioinformatic studies of piRNA biogenesis in Drosophila showed that the piRNA 5′ end is formed by PIWI-Slicer or Zucchini (Zuc) endonucleolytic cleavage, while the 3′ end is formed by Zuc or Nibbler (Nbr) 3′-to-5′ exonucleolytic activity4,5,6. piRNA 3′-end formation in Bombyx was shown to be mediated by PNLDC1/Trimmer (Trim) 3′-to-5′ exonuclease7, while piRNA intermediates are bound with PIWI anchored onto mitochondrial protein PAPI8. However, the requirement for Zuc and Nbr in piRNA biogenesis in Bombyx has not been elucidated. Here, we applied biochemical approaches to understand their involvement in piRNA biogenesis and revealed that Zuc endonuclease, but not Trim and Nbr exonucleases, plays a crucial role in Bombyx piRNA 3′-end formation. Loss of Zuc had little effect on the levels of Trim and Nbr, but led to the aberrant accumulation of piRNA intermediates within the PAPI complex, which were processed to mature piRNAs by recombinant Zuc. Zuc copurified with PAPI, and PAPI exerted RNA-binding activity only when Siwi coexisted with it and PAPI was phosphorylated, suggesting that complex assembly proceeds via a hierarchical process. Bioinformatic analyses of piRNA intermediates within the PAPI complex revealed that both the 5′ and the 3′ ends showed the hallmark of PIWI-Slicer, yet no phasing pattern was observed in mature piRNAs. These findings strongly support the notion that, in Bombyx piRNA, the 5′ end is formed by PIWI-Slicer, but independently of Zuc, while the 3′ end is formed by Zuc endonuclease. The Bombyx piRNA biogenesis is simpler than that of Drosophila, which is reasonable considering that Bombyx has no transcriptional silencing machinery relying on phased piRNAs.
2018-03-01 | GSE107371 | GEO
Project description:In germ cells, piRNAs are amplified through the Ping-Pong cycle that depends on reciprocal Slicer-mediated target RNA cleavage by two PIWI members. A germ-specific DEAD-box protein Vasa is required for the process. However, Vasa’s function is poorly understood. Here, we show that target RNAs cleaved by a Bombyx mori (silkworm) PIWI, Siwi, remain to be bound with the protein upon cleavage, but are released in the presence of Vasa in B. mori (BmVasa) and ATP. Under normal conditions, BmVasa co-purifies with Siwi, but not with second B. mori PIWI BmAgo3. However, when BmVasa loses the ATP-binding and RNA-unwinding activities, BmVasa avidly associates with Siwi and BmAgo3, which contains transposon transcripts predominantly in sense orientation, the sources of BmAgo3-piRNAs. Without BmVasa, BmAgo3 is devoid of piRNAs. Thus, BmVasa actively releases target RNAs from Siwi, upon its cleavage, to urge BmAgo3-piRNA complex formation in the Ping-Pong cycle, enabling continuous supply of piRNAs in germ cells.
2014-12-31 | GSE58221 | GEO
Project description:Piwi-interacting RNAs (piRNAs) are ~24-30 nucleotide regulatory RNAs that are abundantly expressed in gonads. The most well-understood piRNAs mediate post-transcriptional defense against transposable elements (TEs), and derive from sense or antisense strands as a consequence of "ping-pong" amplification of complementary sequences of active TEs and piRNA master control transcripts. Another class of piRNAs, such as those expressed in pachytene testis, derive from large intergenic clusters that are strictly single-stranded. Here, we report a third substrate that generates abundant primary piRNAs. In somatic follicle cells of Drosophila ovaries, we cloned >1 million piRNAs from thousands of messenger RNAs, and these were quite preferentially derived from 3' untranslated regions. This segregation implies a competition between the translation machinery and primary piRNA biogenesis machinery for mRNA access. 3 replicates.
2010-01-03 | E-GEOD-15825 | biostudies-arrayexpress
Project description:Dynamic subcellular compartmentalization ensures the fidelity of piRNA biogenesis in silkworm cells
| PRJDB11110 | ENA
Project description:Dynamic subcellular compartmentalization ensures the fidelity of piRNA biogenesis in silkworm cells
| PRJDB10160 | ENA
Project description:Piwi-interacting RNAs (piRNAs) are ~24-30 nucleotide regulatory RNAs that are abundantly expressed in gonads. The most well-understood piRNAs mediate post-transcriptional defense against transposable elements (TEs), and derive from sense or antisense strands as a consequence of "ping-pong" amplification of complementary sequences of active TEs and piRNA master control transcripts. Another class of piRNAs, such as those expressed in pachytene testis, derive from large intergenic clusters that are strictly single-stranded. Here, we report a third substrate that generates abundant primary piRNAs. In somatic follicle cells of Drosophila ovaries, we cloned >1 million piRNAs from thousands of messenger RNAs, and these were quite preferentially derived from 3' untranslated regions. This segregation implies a competition between the translation machinery and primary piRNA biogenesis machinery for mRNA access.
2010-01-04 | GSE15825 | GEO
Project description:Hsp90 facilitates accurate loading of precursor piRNAs into PIWI proteins
| PRJDB2257 | ENA