Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA308081 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:SIRT7 is an NAD+-dependent protein deacetylase with important roles in ribosome biogenesis and cell proliferation. Previous studies have established that SIRT7 is associated with RNA polymerase I, interacts with pre-rRNA and promotes rRNA synthesis. Here we show that SIRT7 is also associated with snoRNAs that are involved in pre-rRNA processing and rRNA maturation. Knockdown of SIRT7 impairs U3 snoRNA-dependent early cleavage steps that are necessary for generation of 18S rRNA. Mechanistically, SIRT7 deacetylates U3-55k, a core component of the U3 snoRNP complex, and reversible acetylation of U3-55k modulates the association of U3-55k with U3 snoRNA. Deacetylation by SIRT7 enhances U3-55k binding to U3 snoRNA, which is a prerequisite for pre-rRNA processing. Under stress conditions, SIRT7 is released from nucleoli, leading to hyperacetylation of U3-55k and attenuation of prerRNA processing. The results reveal a multifaceted role of SIRT7 in ribosome biogenesis, regulating both transcription and processing of rRNA. CLIP-seq was performed in Flag-SIRT7-293T cells.
2016-01-07 | E-GEOD-76578 | biostudies-arrayexpress
Project description:SIRT7 is an NAD+-dependent protein deacetylase with important roles in ribosome biogenesis and cell proliferation. Previous studies have established that SIRT7 is associated with RNA polymerase I, interacts with pre-rRNA and promotes rRNA synthesis. Here we show that SIRT7 is also associated with snoRNAs that are involved in pre-rRNA processing and rRNA maturation. Knockdown of SIRT7 impairs U3 snoRNA-dependent early cleavage steps that are necessary for generation of 18S rRNA. Mechanistically, SIRT7 deacetylates U3-55k, a core component of the U3 snoRNP complex, and reversible acetylation of U3-55k modulates the association of U3-55k with U3 snoRNA. Deacetylation by SIRT7 enhances U3-55k binding to U3 snoRNA, which is a prerequisite for pre-rRNA processing. Under stress conditions, SIRT7 is released from nucleoli, leading to hyperacetylation of U3-55k and attenuation of prerRNA processing. The results reveal a multifaceted role of SIRT7 in ribosome biogenesis, regulating both transcription and processing of rRNA.
2016-01-07 | GSE76578 | GEO
Project description:Fibrillarin (FBL) is a dual function nucleolar protein which catalyses 2´-O methylation of pre-rRNA and methylation of histone H2A at glutamine 104 (H2AQ104me). The mechanisms that regulate FBL activity are unexplored. Here we show that FBL is acetylated at several lysine residues by the acetyltransferase CBP and deacetylated by SIRT7. While reversible acetylation does not impact FBL-mediated pre-rRNA methylation, hyperacetylation impairs the interaction of FBL with histone H2A and chromatin, thereby compromsing H2AQ104 methylation (H2AQ104me) and rDNA transcription. SIRT7-dependent deacetylation of FBL ensures H2AQ104me and high levels of rRNA synthesis during interphase. At the onset of mitosis, nucleolar disassembly is accompanied by hyperacetylation of FBL, loss of H2AQ104me and repression of Pol I transcription. H2AQ104me and transcriptional activity are restored by overexpression of an acetylation-deficient but not by an acetylation-mimicking FBL mutant. The results reveal that SIRT7-dependent deacetylation impacts nucleolar activity by a FBL-driven circuitry that mediates cell cycle-dependent fluctuation of rDNA transcription.
2018-12-12 | GSE115360 | GEO
Project description:In eukaryotes, biogenesis of ribosomes requires folding and assembly of the precursor rRNA (pre-rRNA) with a large number of proteins and snoRNPs into huge RNA-protein complexes. In spite of intense genetic, biochemical and high resolution cryo-EM studies in Saccharomyces cerevisiae, information about the conformation of the earliest 35S pre-rRNA is limited. To overcome this, we performed high-throughput SHAPE chemical probing on the 35S pre-rRNA associated with 90S pre-ribosomes. We focused our analyses on external (5´ETS) and internal (ITS1) transcribed spacers as well as the 18S region. We show that in the 35S pre-rRNA, the central region of the 18S is in a more open configuration compared to 20S pre-rRNA and that the central pseudoknot is not formed. The essential ribosome biogenesis protein Mrd1 influences the structure of the 18S part locally and is involved in organizing the central pseudoknot and surrounding structures. Our results demonstrate that the U3 snoRNA dynamically interacts with the 35S pre-rRNA and that Mrd1 is required for disrupting U3 snoRNA base-pairing interactions in the 5'ETS. We propose that the dynamic U3 snoRNA interactions and Mrd1 are essential for establishing the structure of the central region of 18S that is required for processing and 40S subunit function.
2018-01-15 | GSE106868 | GEO
Project description:Purpose: Pre-ribosomal RNA is cleaved at defined sites, but many endonucleases involved in 18S rRNA release are not known. We apply an in vivo cross-linking technique coupled with deep sequencing (CRAC) that captures transcriptome-wide interactions between a yeast candidate pre-rRNA endonuclease (Utp24) and its targets in a living cell. Methods: We apply CRAC to an HTP-tagged Utp24 protein (HTP: His6 - TEV cleavage site - two copies of the z-domain of Protein A). At least two independent experiments were performed and analyzed separately. Results: We found that yeast Utp24 UV-crosslinked in vivo to the U3 snoRNA and all (pre-)rRNA elements that form the central pseudoknot in the 18S rRNA. The pseudoknot is an evolutionarily highly conserved structure that is required to ensure pre-rRNA processing at three cleavage sites (A0, A1 and A2) and still present in the mature rRNA. According to our crosslinking data, the endonuclease Utp24 is placed in close proximity to site A1 at the 5'-end of the 18S rRNA. Conclusion: Our study strongly supports the hypothesis that Utp24 cleaves pre-rRNA at sites A1 and A2. Examination of targets for pre-rRNA endonucleases in yeast cells.
2016-04-01 | E-GEOD-75991 | biostudies-arrayexpress
Project description:Osteoarthritis (OA) is a chronic debilitating joint disease which is strongly associated with ageing. OA involves pathological cellular processes in all joint structures and affects articular cartilage integrity, leading to dysfunctional joint articulation. The biomolecular processes that catalyze the disturbances in the articular chondrocyte phenotype leading to OA are poorly understood, and it is expected that a comprehensive understanding of the avenues leading to catabolic changes and disruption of articular chondrocyte homeostasis will provide important cues for future treatments of the condition. Chondrocytes are specialized secretory cells with highly active protein translational machinery, enabling the synthesis and maintenance of the protein-rich cartilage extracellular matrix (ECM). Disturbances in chondrocyte protein translation in cartilage development and OA are connected to mTOR activity, ER stress, unfolded protein response (UPR)and CHOP-mediated apoptosis. These responses change the downstream translational activity of the biosynthesized ribosome. The assembled mammalian ribosome is built from ribosomal RNAs (rRNAs), together with more than 80 different protein subunits. At the heart of the ribosome, the 18S rRNA guides the decoding of the mRNA message, while an ancient ribozyme activity in the 28S rRNA forms the core of the peptidyltransferase center that polymerizes the amino acid sequence encoded by the mRNA into functional proteins. Post-transcriptional maturation of rRNAs is an integral part of the biosynthesis of ribosomes and ribonucleolytic processing of the major 47S rRNA precursor into mature 18S, 5.8S, and 28S rRNAs is rate limiting for ribosome biogenesis. The U3 small nucleolar RNA (snoRNA) is an evolutionarily highly conserved box C/D-class snoRNA which catalyzes the endoribonucleolytic processing of the 5’ external transcribed spacer (ETS) of the 47S pre-rRNA by base complementarity-guided pre-rRNA substrate recognition and plays a crucial role in the maturation of 18S rRNA. Although extensively studied in yeast, it was only recently demonstrated that U3 snoRNA is indispensable for rRNA maturation in human cells. Pathways controlling ribosome activity have previously been described in the regulation of chondrocyte homeostasis. We here now postulate that not only ribosome activity is involved in chondrocyte homeostasis, but that OA pathophysiological situations can also cause alterations in chondrocyte ribosome biogenesis with consequences for cellular protein translation. Since U3 snoRNA-driven rRNA production is rate-limiting in ribosome biogenesis, we hypothesized that the U3 snoRNA is critical for chondrocyte homeostasis. In this study we therefor aimed to determine whether OA pathophysiological conditions interact with chondrocyte U3 snoRNA levels, thereby influencing rRNA levels and chondrocyte translation capacity.
2020-08-21 | PXD017253 | Pride
Project description:SIRT7-dependent deacetylation of fibrillarin controls H2A methylation and rRNA synthesis during the cell cycle
| PRJNA474692 | ENA
Project description:Purpose: Pre-ribosomal RNA is cleaved at defined sites, but many endonucleases involved in 18S rRNA release are not known. We apply an in vivo cross-linking technique coupled with deep sequencing (CRAC) that captures transcriptome-wide interactions between a yeast candidate pre-rRNA endonuclease (Utp24) and its targets in a living cell. Methods: We apply CRAC to an HTP-tagged Utp24 protein (HTP: His6 - TEV cleavage site - two copies of the z-domain of Protein A). At least two independent experiments were performed and analyzed separately. Results: We found that yeast Utp24 UV-crosslinked in vivo to the U3 snoRNA and all (pre-)rRNA elements that form the central pseudoknot in the 18S rRNA. The pseudoknot is an evolutionarily highly conserved structure that is required to ensure pre-rRNA processing at three cleavage sites (A0, A1 and A2) and still present in the mature rRNA. According to our crosslinking data, the endonuclease Utp24 is placed in close proximity to site A1 at the 5'-end of the 18S rRNA. Conclusion: Our study strongly supports the hypothesis that Utp24 cleaves pre-rRNA at sites A1 and A2.
2016-04-01 | GSE75991 | GEO
Project description:The CRAC UV crosslinking technique identified numerous pre-rRNA binding sites for the large, highly conserved ribosome synthesis factor Rrp5. Intramolecular complementation has shown that the C-terminal domain (CTD) of Rrp5 is required for pre-rRNA cleavage at sites A0-A2 on the pathway of 18S rRNA synthesis, whereas the N-terminal domain (NTD) is required for A3 cleavage on the pathway of 5.8S/25S rRNA synthesis. The CTD was crosslinked to sequences flanking A2 and to the snoRNAs U3, U14, snR30 and snR10, which are required for cleavage at A0-A2. The NTD was crosslinked to the sequence flanking A3 and to the RNA component of RNase MRP, which cleaves site A3. Rrp5 could also be directly crosslinked to several large structural protein factors and NTPases. A key role in coordinating pre-ribosomal assembly and processing was confirmed by "Miller" chromatin spreads. Following depletion of Rrp5, cotranscriptional cleavage was lost and pre-ribosome compaction greatly reduced.
2013-10-14 | GSE47680 | GEO
Project description:NOL12 5'-3' exoribonucleases, conserved among eukaryotes, play important roles in pre-rRNA processing, ribosome assembly and export. The most well-described yeast counterpart, Rrp17, is required for maturation of 5.8 and 25S rRNAs, whereas human hNOL12 is crucial for the separation of the large (LSU) and small (SSU) ribosome subunit rRNA precursors. In this study we demonstrate that plant AtNOL12 is also involved in rRNA biogenesis, specifically in the processing of the LSU rRNA precursor, 27S pre-rRNA. Importantly, the absence of AtNOL12 alters the expression of many ribosomal protein and ribosome biogenesis genes. These changes could potentially exacerbate rRNA biogenesis defects, or, conversely, they might stem from the disturbed ribosome assembly caused by delayed pre-rRNA processing. Moreover, exposure of the nol12 mutant to stress factors, including heat and pathogen Pseudomonas syringae, enhances the observed molecular phenotypes, linking pre-rRNA processing to stress response pathways. The aberrant rRNA processing, dependent on AtNOL12, could impact ribosome function, as suggested by improved mutant resistance to ribosome-targeting antibiotics. Despite extensive studies, the pre-rRNA processing pathway in plants remains insufficiently characterized. Our investigation reveals the involvement of AtNOL12 in the maturation of rRNA precursors, correlating this process to stress response in Arabidopsis. These findings contribute to a more comprehensive understanding of plant ribosome biogenesis.
2023-11-07 | GSE232067 | GEO