Structural basis of MALAT1 RNA maturation and mascRNA biogenesis
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE248290 | GEO | 2024/03/18
REPOSITORIES: GEO
Similar Datasets
Project description:Abstract: tRNAs are highly modified in the elbow region and harbor 5-methyluridine at position 54 and pseudouridine at position 55 in the T arm, which are generated by the enzymes TrmA and TruB, respectively. Although all elongator tRNAs contain these modifications across all domains of life, the cellular relevance of these modifications and their corresponding modifying enzymes remains elusive. In addition to modifying every tRNA, Escherichia coli TrmA and TruB have both been shown to fold tRNA independently of its modification activity acting as tRNA chaperones, and strains lacking trmA or truB are outcompeted by wildtype. To identify how TrmA and TruB contribute to cellular fitness, we have systematically assessed the effects of deleting trmA and/or trmB in E. coli. Since tRNA folding is a pre-requisite for tRNA aminoacylation, we determined cellular aminoacylation levels revealing a global decrease in aminoacylation for all tRNAs in ΔtrmA and ΔtruB. Moreover, the absence of 5-methyluridine 54 or pseudouridine 55 alters tRNA modification at other positions: whereas acp3U47 is decreased, thiouridine levels are increased. Understanding the importance of TrmA and TruB for tRNA aminoacylation and modification, we then analyzed how these global tRNA changes in ΔtrmA and ΔtruB strains affect translation. Whereas global protein synthesis is not significantly changed in ΔtrmA and ΔtruB, the abundances of many specific proteins are altered, and transcriptomics experiments suggest that the dysregulation of many proteins is controlled at the translational level. In conclusion, we demonstrate that universally conserved modifications of the tRNA elbow are critical for global tRNA function by enhancing other tRNA modifications, tRNA folding, tRNA aminoacylation and translation of specific genes thereby contributing to cellular fitness.
2023-05-31 | GSE233667 | GEO
Project description:In animals the organization of the compact mitochondrial genome and lack of introns have necessitated a unique mechanism for RNA processing. To date the regulation of mitochondrial RNA processing and its importance for ribosome biogenesis and energy metabolism are not clear. To understand the in vivo role of the endoribonuclease component of the RNase P complex, MRPP3, we created conditional knockout mice. Here we show that MRPP3 is essential for life, and heart and skeletal muscle-specific knockout leads to a cardiomyopathy early in life, indicating that it is the only RNase P enzyme in mitochondria. We show that RNA processing is required for the biogenesis of the respiratory chain and mitochondrial function. Transcriptome-wide parallel analyses of RNA ends (PARE) and RNA-Seq enabled us to identify the in vivo cleavage sites of RNase P. Cleavage of the 5′ tRNA ends precedes 3′ end processing in vivo and is required for the correct biogenesis of the mitochondrial ribosomal subunits and mitoribosomal proteins that are differentially stabilized or degraded in the absence of mature rRNAs. Finally we identify that large mitoribosomal proteins can form a subcomplex on a precursor mt-RNA containing the 16S rRNA indicating that mitoribosomal biogenesis proceeds co-transcriptionally. Taken together our data show that RNA processing links transcription to translation via assembly of the mitoribosome.
2016-08-04 | GSE83471 | GEO
Project description:Protein translation is an essential cellular process, but paradoxically, it can also promote aging and other stresses. In a screen for mutations that protect C. elegans from hypoxic stress, we isolated multiple genes that impact translation, including a ribosomal RNA helicase gene, ddx-52, tRNA biosynthesis genes, and a gene controlling amino acid availability. To better define the mechanisms whereby these genes control hypoxic injury, we performed a second screen for genetic suppressors of the ddx-52(lf) phenotypes. This screen identified multiple genes involved in ribosome biogenesis. Surprisingly, the suppressor mutations were able to restore normal hypoxic sensitivity and protein synthesis to the tRNA biosynthesis mutants, but not to the mutant reducing amino acid uptake. Proteomic characterization of the mutants demonstrated that reduced tRNA biosynthetic activity produces a corresponding reduction in ribosomal structural subunits. Our study uncovers an uncharacterized regulatory interaction between ribosomal biogenesis and tRNA abundance controlling translation and hypoxic survival. A proteomic analysis of a threonyl-tRNA synthetase mutant with and without the ribosomal biogenesis suppressors revealed an uncharacterized feedback mechanism whereby disruption of tRNA aminoacylation results in a corresponding reduction in ribosomal subunits, thereby explaining the ability of enhanced ribosomal biogenesis to suppress reduced tRNA aminoacylation.
2022-02-15 | PXD017267 | Pride
Project description:In animals the organization of the compact mitochondrial genome and lack of introns have necessitated a unique mechanism for RNA processing. To date the regulation of mitochondrial RNA processing and its importance for ribosome biogenesis and energy metabolism are not clear. To understand the in vivo role of the endoribonuclease component of the RNase P complex, MRPP3, we created conditional knockout mice. Here we show that MRPP3 is essential for life, and heart and skeletal muscle-specific knockout leads to a cardiomyopathy early in life, indicating that it is the only RNase P enzyme in mitochondria. We show that RNA processing is required for the biogenesis of the respiratory chain and mitochondrial function. Transcriptome-wide parallel analyses of RNA ends (PARE) and RNA-Seq enabled us to identify the in vivo cleavage sites of RNase P. Cleavage of the 5â² tRNA ends precedes 3â² end processing in vivo and is required for the correct biogenesis of the mitochondrial ribosomal subunits and mitoribosomal proteins that are differentially stabilized or degraded in the absence of mature rRNAs. Finally we identify that large mitoribosomal proteins can form a subcomplex on a precursor mt-RNA containing the 16S rRNA indicating that mitoribosomal biogenesis proceeds co-transcriptionally. Taken together our data show that RNA processing links transcription to translation via assembly of the mitoribosome. Total RNA was isolated from heart tissue from 11 week old control (Mrpp3loxP/loxP) and Mrpp3 knockout mice (Mrpp3loxP/loxP, +/Ckmm), TruSeq libraries produced in triplicate, sequenced and analysed for differential expression. Mitochondrial RNA was isolated from heart tissue from 11 week old control (Mrpp3loxP/loxP) and Mrpp3 knockout mice (Mrpp3loxP/loxP, +/Ckmm), PARE libraries produced in triplicate and sequenced for analysis of mitochondrial RNA processing.
2016-08-04 | E-GEOD-83471 | biostudies-arrayexpress
Project description:Ribosome biogenesis relies on a number of specific factors. Some of them are remarkably conserved, suggesting that they play essential roles even in distant evolutionary contexts. This is namely the case for the UPF0054 protein YBEY found in all bacteria, but also in many Eukarya. Proposed to act as an endoribonuclease processing the 3’ end of 16S rRNA, YBEY is critically required for translation in model bacteria and plant chloroplasts. However, ribosomal RNA processing pathways are poorly conserved between distant phyla, suggesting that YBEY may have another important function in ribosome biogenesis. We studied the human YBEY homologue and found that it localises in mitochondria. The human mitochondrial rRNAs are flanked by tRNA genes and thereby processed by mitochondrial RNase P and RNase Z, making other ribonucleases superfluous. Yet, CRISPR-mediated knockout of the YBEY gene resulted in a decrease of the mitochondrial small ribosomal subunits (SSU), abolished translation in the organelles and, as a result, led to the inability of the knockout cells to respire. Mapping the ends of the mitochondrial rRNAs revealed no processing defects. Similarly, although human YBEY did show robust RNase activity in vitro and in vivo, mutations in key catalytic residues did not abolish its ability to complement the knockout phenotypes. The analysis of the mitoribosomes identified a distinct set of SSU proteins, mostly located in the head and the platform, to be significantly depleted in the absence of YBEY, including uS11m, required for translation initiation. Importantly, uS11m was the only SSU protein found to directly interact with YBEY in vitro, in vivo and in situ, and forming a stable stoichiometric complex with YBEY. The sum of our data supports the model where YBEY functions primarily as an essential ribosome biogenesis factor by recruiting uS11m in order to complete the assembly of translationally active SSUs.
2020-02-26 | GSE134960 | GEO
Project description:We report here the consequences of loss of Saccharomyces cerevisiae RNase H2 by comparing mRNA expression profiles in wild type yeast versus a strain lacking the RNH201 gene, encoding the catalytic subunit. Deleting RHN201 alters mRNA expression for hundreds of genes. Expression changes were based on seven biological replicates (3 from one batch and 4 from another batch) and are seen for many genes involved in stress responses and genome maintenance, consistent with a role of RNase H2 in removing ribonucleotides incorporated into DNA during replication. Differentially expressed genes include, those involved in ribosomal RNA processing and biogenesis and in tRNA modification, supports a role for RNase H2 in resolving R-loops formed during transcription of rRNA and tRNA. Other differentially expresses genes include putative or known helicases and nucleases maintenance of dsRNA viruses, which could be relevant to how mammalian RNase H2 dysfunction elicits an innate immune response leading to neurodegeneration.
2012-12-20 | GSE34668 | GEO
Project description:We report here the consequences of loss of Saccharomyces cerevisiae RNase H2 by comparing mRNA expression profiles in wild type yeast versus a strain lacking the RNH201 gene, encoding the catalytic subunit. Deleting RHN201 alters mRNA expression for hundreds of genes. Expression changes were based on seven biological replicates (3 from one batch and 4 from another batch) and are seen for many genes involved in stress responses and genome maintenance, consistent with a role of RNase H2 in removing ribonucleotides incorporated into DNA during replication. Differentially expressed genes include, those involved in ribosomal RNA processing and biogenesis and in tRNA modification, supports a role for RNase H2 in resolving R-loops formed during transcription of rRNA and tRNA. Other differentially expresses genes include putative or known helicases and nucleases maintenance of dsRNA viruses, which could be relevant to how mammalian RNase H2 dysfunction elicits an innate immune response leading to neurodegeneration. We examine the consequences of loss of Saccharomyces cerevisiae RNase H2 by comparing mRNA expression profiles in wild type yeast versus a strain lacking the RNH201 gene encoding the catalytic subunit. Expression changes were based on seven biological replicates (3 from one batch and 4 from another batch). For strain reference please see S.A. Nick McElhinny, et al, Genome instability due to ribonucleotide incorporation into DNA, Nat Chem Bio 6, 774-781 (2010).
2012-12-20 | E-GEOD-34668 | biostudies-arrayexpress
Project description:The Synthetase Sequestration Model (SSM) is a simplified translation model that considers explicitly two main steps in the process of tRNA aminoacylation: first, the tRNA is bound by the aminoacyl tRNA synthetase, and in a second step, the amino acid is attached to the tRNA. The tRNA then participates in the translation reaction, becoming deacylated as a result. The tRNA exists in states bound, charged and uncharged. In the bound state, the tRNA is bound to the synthetase but uncharged, i.e., the tRNA is sequestered by the synthetase. The model predicts how the balance between the three different tRNA states (empty, bound and charged) changes depending on aminoacyl tRNA synthetase availability.
2020-02-05 | MODEL2001080005 | BioModels
Project description:When eukaryotic cells are deprived of amino acids, uncharged tRNAs accumulate and activate the conserved GCN2 protein kinase. We examine how yeast growth and tRNA charging or aminoacylation is affected during amino acid depletion in the presence and absence of GCN2. tRNA charging is measured using a microarray technique which allows for simultaneous measurement of all cytosolic tRNAs. A fully prototrophic and its isogenic GCN2 deletion strain were used. We measured relative tRNA charging levels in yeast strains with an intact and deleted GCN2.
2010-08-01 | E-GEOD-22452 | biostudies-arrayexpress
Project description:Aminoacyl-tRNA synthetases (aaRSs) are essential enzymes that ligate amino acids to tRNAs, and often require editing to ensure accurate protein synthesis. Recessive mutations in aaRSs cause various neurological disorders in humans, yet the underlying mechanism remains poorly understood. Pathogenic aaRS mutations frequently cause protein destabilization and aminoacylation deficiency. In this study, we report that combined aminoacylation and editing defects cause severe proteotoxicity. We show that a C268A mutation in yeast threonyl-tRNA synthetase (ThrRS) abolishes editing and causes heat sensitivity. Surprisingly, directed-evolution of the C268A mutant result in intragenic mutations that restore heat resistance but not editing. C268A destabilizes ThrRS and decreases overall Thr-tRNAThr synthesis, and the suppressor mutations in the evolved strains improve aminoacylation. We further show that deficiency in ThrRS aminoacylation or editing alone is not sufficient to cause heat sensitivity, and that C268A impairs ribosome-associated quality control. Our results suggest that aminoacylation deficiency predisposes cells to proteotoxic stress.
2024-01-26 | PXD042145 | Pride