Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Regulation of Ex-Translational Activities Is Primary Function of Multi-tRNA Synthetase Complex

ABSTRACT: During mRNA translation, tRNAs are charged by aminoacyl-tRNA synthetases (aaRS) and subsequently used by ribosomes. A multi-enzyme aminoacyl-tRNA synthetase complex (MSC) has long been proposed to increase protein synthesis efficiency by passing charged tRNAs directly to ribosomes. An alternative is that the MSC repurposes specific synthetases for ex-translational functions that are activated by cues that direct specific enzymes to novel targets. To explore this question, we generated mammalian cell clones in which ArgRS and GlnRS were absent from the MSC to give a stable complex lacking the two enzymes (MSCΔRQ). Protein synthesis, under a variety of stress conditions, was unchanged in MSCΔRQ cells. Most strikingly, levels of charged tRNAGln and tRNAArg remained unchanged and no ribosome pausing was observed at codons for Arg and Gln. Thus, increasing or regulating protein synthesis efficiency is not dependent on ArgRS and GlnRS in the MSC. Alternatively, and consistent with previously reported ex-translational roles, we found manipulations that do not affect protein synthesis but instead MSC cellular localization.

ORGANISM(S): Homo sapiens

PROVIDER: GSE158212 | GEO | 2020/11/18

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Methionyl-tRNA synthetase interactome

Project description:During mRNA translation, tRNAs are charged by aminoacyl-tRNA synthetases (aaRS) and subsequently used by ribosomes. A multi-enzyme aminoacyl-tRNA synthetase complex (MSC) has long been proposed to increase protein synthesis efficiency by passing charged tRNAs directly to ribosomes. An alternative is that the MSC repurposes specific synthetases for ex-translational functions that are activated by cues that direct specific enzymes to novel targets. To explore this question, we generated mammalian cell clones in which ArgRS and GlnRS were absent from the MSC to give a stable complex lacking the two enzymes (MSCΔRQ). Protein synthesis, under a variety of stress conditions, was unchanged in MSCΔRQ cells. Most strikingly, levels of charged tRNAGln and tRNAArg remained unchanged and no ribosome pausing was observed at codons for Arg and Gln. Thus, increasing or regulating protein synthesis efficiency is not dependent on ArgRS and GlnRS in the MSC. Alternatively, and consistent with previously reported ex-translational roles, we found manipulations that do not affect protein synthesis but instead MSC cellular localization.

2020-12-23 | PXD021527 | Pride

McFarland2020 - Totally Asymmetric Simple Exclusion Process (TASEP) model describing the movement of particles (ribosomes) along a lattice (the mRNA)

Project description:A stochastic simulation of yeast translation using Total Asymmetric Simple Exclusion Principle (TASEP) principles, representing ribosomes, tRNAs, mRNAs, and a tRNA re-charging process involving aminoacyl tRNA synthetases

2020-02-05 | MODEL2001080004 | BioModels

Ribo-seq of HEK293T overexpressing WT and G240R GARS

Project description:Charcot-Marie-Tooth (CMT) disease can be caused by mutations in Aminoacyl-tRNA-Synthetases, including G240R mutation in Glycyl-tRNA-Synthetase (GARS). Ribo-seq generates snapshots of translating ribosomes on mRNA and therefore allows analysis of ribosome pausing mRNA. Here we performed Ribo-seq on lysates of HEK293T cells overexpressing GARS, WT or G240R, to dissect mechanism of CMT linked with translation. We found that GARS G240R causes pausing of ribosomes with glycine codons in A-site. The effect is specific for 21 nt ribosome-protected fragments, produced by ribosomes with empty A-sites, suggestive of the deficit of charged Glycyl-tRNA in GARS G240R-CMT.

2021-09-14 | E-MTAB-10342 | biostudies-arrayexpress

Growth Optimized Aminoacyl-tRNA Synthetase Levels Prevent Maximal tRNA Charging

Project description:Summary Aminoacyl-tRNA synthetases (aaRSs) serve a dual role in charging tRNAs. Their enzymatic activities both provide protein synthesis flux and reduce uncharged tRNA levels. Although uncharged tRNAs can negatively impact bacterial growth, substantial concentrations of tRNAs remain deacylated even under nutrient-rich conditions. Here we show that tRNA charging in Bacillus subtilis is not maximized due to optimization of aaRS production during rapid growth, which prioritizes demands in protein synthesis over charging levels. The presence of uncharged tRNAs is alleviated by precisely tuned translation kinetics and the stringent response, both insensitive to aaRS overproduction but sharply responsive to underproduction, allowing for just-enough aaRS production atop a “fitness cliff”. Notably, we find that the stringent response mitigates fitness defects at all aaRS underproduction levels even without external starvation. Thus, adherence to minimal, flux-satisfying protein production drives limited tRNA charging and provides a basis for the sensitivity and setpoints of an integrated growth-control network.

2020-07-20 | GSE141389 | GEO

Yeast glutamine tRNA synthetase doxycycline shut-off

Project description:During protein synthesis, charged tRNAs deliver amino acids to translating ribosomes, and are then re-charged by tRNA synthetases (aaRS). In humans, mutant aaRS cause a diversity of neurological disorders, but their molecular aetiologies are incompletely characterised. To understand system responses to aaRS depletion, the yeast glutamine aaRS gene (GLN4) was transcriptionally regulated using doxycycline by tet-off control. Depletion of Gln4p inhibited growth, and induced a transcriptional GCN4 amino acid starvation response, indicative of uncharged tRNA accumulation and Gcn2 kinase activation. The GCN4 response was confirmed using SILAC proteomics, using heavy isotope labelling to identify changes in protein expression during glutamine tRNA synthetase depletion.

2020-02-12 | PXD017140 | Pride

Genome-wide screening reveals metabolic regulation of translational fidelity by cyclic AMP

Project description:Translational quality control is critical for maintaining the accuracy of protein synthesis in all domains of life. Mutations in aminoacyl-tRNA synthetases and the ribosome are known to affect translational fidelity and alter fitness, viability, stress responses, neuron function, and life span. In this study, we used a high-throughput fluorescence-based assay to screen a knock-out library of Escherichia coli and identified 30 nonessential genes that are critical for maintaining the fidelity of stop-codon readthrough. Most of these identified genes have not been shown to affect translational fidelity previously. Intriguingly, we show that several genes controlling metabolism, including cyaA and guaA, unexpectedly enhance stop-codon readthrough. CyaA and GuaA catalyze the synthesis of cyclic adenosine monophosphate (cAMP) and guanosine monophosphate (GMP), respectively. Both CyaA and GuaA increase the expression of ribosomes and tRNAs, allowing aminoacyl-tRNAs to compete with release factors and suppress stop codons. In addition, the effect of guaA deletion on stop-codon readthrough is abolished by deleting prfC, which encodes release factor 3 (RF3). Our results suggest that nucleotide and carbon metabolism is tightly coupled with translational fidelity.

2023-03-28 | GSE228051 | GEO

tRNA synthetases are recruited to yeast ribosomes by rRNA expansion segment 7L but do not require association for func-tionality

Project description:Ribosomes expanded during evolution on the protein and rRNA level. The expanded regions do not change the active sites of ribosomes and thus do not alter the peptide bond formation reaction catalysed by the ribosome. To what purpose these expansions were selected is not fully understood. Here, we deleted one rRNA expansion segment (ES7La) and addressed physiological consequences. We found a mild ribosome biogenesis defect accompanied by slightly reduced translation. On a molecular level, ribosomes displayed reduced association to three aminoacyl-tRNA synthetases. Loss of ribosome binding however did not alter synthetase activity suggesting, that tRNAs are not channelled for enhanced local translation in the case of these synthetases.

2022-02-16 | PXD029751 | Pride

Adaptation of human cells to protein synthesis errors

Project description:Protein synthesis is a highly regulated process and maintenance of its fidelity is essential to life. Alterations in the components of the protein synthesis machinery, namely RNAs, aminoacyl-tRNA synthetases (aaRS) or tRNA modifying enzymes, increase the level of protein synthesis errors (PSE), and are associated with several conditions, from cancer to neurodegeneration. Still, the cause-effect mechanisms remain to be elucidated in many conditions. In order to have a global picture of how human cells respond and adapt in culture we created stable HEK293 cell lines that express mutant tRNAs. For this, we modified the anticodon of a human serine transfer RNA (tRNASer), to incorporate the amino acid serine (Ser) at various non-cognate sites and overexpressed the wild type tRNASer to evaluate the effects of tRNA misexpression. DNA microarrays were then performed to identify the transcriptional deregulation induced by PSE of cells in culture at different time points (cells passages).

2020-01-22 | GSE93854 | GEO

McFarland2020 - Synthetase sequestration Model:a combined translation and tRNA charging cycle

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

Mammalian mitochondrial translation infidelity leads to oxidative stress-induced cell cycle arrest and cardiomyopathy

Project description:Editing of mischarged tRNAs by cytoplasmic aminoacyl-tRNA synthetases (aaRSs) is of high significance for protein homeostasis, whose impairment causes neurodegeneration. However, whether mitochondrial translation needs fidelity and the significance of proofreading (editing) by mitochondrial aaRSs are long-term mysteries. Here, we showed that NIH-3T3 cell line critically depend on the editing of mitochondrial threonyl-tRNA synthetase (Tars2) editing, the disruption of which accumulated Ser-tRNAThr and generated a large abundance of Thr-to-Ser misincorporated peptides. Such infidelity impaired mitochondrial translation and oxidative phosphorylation, causing oxidative stress and cell cycle arrest at G0/G1 phase. ROS removal by N-acetylcysteine relieved abnormal cell proliferation.

2023-08-25 | GSE232410 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data