Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Ribosome-quality control antagonizes the activation of integrated-stress response on colliding ribosomes

ABSTRACT: Ribosome stalling occurring on aberrant mRNA activates quality control pathways to maintain proteostasis. Recently, ribosome stalling has also been linked to the activation of Gcn2 and the subsequent integrated-stress response (ISR). How the two processes are coordinated is not completely clear. Here we show that activation of ribosome-quality control by Hel2 suppresses that of Gcn2 in yeast. In the absence of Hel2, we observe a gene-expression signature indicative of ISR activation, suggesting that factor is used to suppress premature activation of Gcn2 in the absence of stress conditions. We further show that Hel2 and Gcn2 are activated by similar set of agents that cause ribosome stalling, with Hel2’s maximal activation occurring at lower frequency of stalling. Interestingly, inactivation of one pathway was found to result in the overactivation of the other, suggesting that both are activated by the same signal. Indeed, we provide evidence that suggests that, similar to Hel2, Gcn2 is activated by ribosome collisions. Collectively, our findings provide interesting details about how the multiple pathways that recognize stalled ribosomes coordinate to mount the appropriate response.

ORGANISM(S): Saccharomyces cerevisiae

PROVIDER: GSE150790 | GEO | 2020/05/19

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Examination of gene expression in cerebellum of mouse strains B6J, B6J-nmf205-/-, B6J-Gcn2-/- and B6J-nmf205-/-;Gcn2-/-.

Project description:Ribosome stalling during translation has recently been shown to cause neurodegeneration, yet the signaling pathways triggered by stalled elongation complexes are unknown. To investigate these pathways we analyzed the brain of B6J-nmf205-/- mice in which neuronal elongation complexes are stalled at AGA codons due to deficiencies in a tRNA Arg(UCU) tRNA and GTPBP2, a mammalian ribosome rescue factor. Increased levels of phosphorylation of eIF2Î± (Ser51) were detected prior to neurodegeneration in these mice and transcriptome analysis demonstrated activation of ATF4, a key transcription factor in the integrated stress response (ISR) pathway. Genetic experiments showed that this pathway was activated by the eIF2alpha kinase, GCN2, in an apparent deacylated tRNA-independent fashion. Further we found that the ISR attenuates neurodegeneration in B6J-nmf205-/- mice, underscoring the importance of cellular and stress context on the outcome of activation of this pathway. These results demonstrate the critical interplay between translation elongation and initiation in regulating neuron survival during cellular stress. Examination of gene expression in cerebellum and hippocampus for 4 mice strains derived from C57BL/6J (B6J) strain. Microarray data was performed for 3 week and 5 week old mice in both cerebellum and hippocampus for B6J and B6J-nmf205-/- three replicates each. RNA-Seq data was perform on cerebellum of mice 3 weeks old, three replicates for each genotype: B6J, B6J-nmf205-/-, B6J-Gcn2-/- and B6J-nmf205-/-;Gcn2-/-.

2016-06-15 | E-GEOD-79929 | biostudies-arrayexpress

Examination of gene expression in cerebellum and hippocampus for mouse C57BL/6J WT and nmf205-/-

Project description:Ribosome stalling during translation has recently been shown to cause neurodegeneration, yet the signaling pathways triggered by stalled elongation complexes are unknown. To investigate these pathways we analyzed the brain of B6J-nmf205-/- mice in which neuronal elongation complexes are stalled at AGA codons due to deficiencies in a tRNA Arg(UCU) tRNA and GTPBP2, a mammalian ribosome rescue factor. Increased levels of phosphorylation of eIF2Î± (Ser51) were detected prior to neurodegeneration in these mice and transcriptome analysis demonstrated activation of ATF4, a key transcription factor in the integrated stress response (ISR) pathway. Genetic experiments showed that this pathway was activated by the eIF2Î± kinase, GCN2, in an apparent deacylated tRNA-independent fashion. Further we found that the ISR attenuates neurodegeneration in B6J-nmf205-/- mice, underscoring the importance of cellular and stress context on the outcome of activation of this pathway. These results demonstrate the critical interplay between translation elongation and initiation in regulating neuron survival during cellular stress. Examination of gene expression in cerebellum and hippocampus for 4 mice strains derived from C57BL/6J (B6J) strain. Microarray data was performed for 3 week and 5 week old mice in both cerebellum and hippocampus for B6J and B6J-nmf205-/- three replicates each. RNA-Seq data was perform on cerebellum of mice 3 weeks old, three replicates for each genotype: B6J, B6J-nmf205-/-, B6J-Gcn2-/- and B6J-nmf205-/-;Gcn2-/-.

2016-06-15 | E-GEOD-79926 | biostudies-arrayexpress

GTPBP1 resolves paused ribosomes to maintain neuronal homeostasis

Project description:Ribosome-associated quality control pathways respond to defects in translational elongation to recycle arrested ribosomes and degrade aberrant polypeptides and mRNAs. Loss of an individual tRNA gene leads to ribosomal pausing that is resolved by the translational GTPase GTPBP2, and in its absence causes neuron death. Here we show that loss of the homologous protein GTPBP1 during tRNA deficiency in the mouse brain also leads to codon-specific ribosome pausing and neurodegeneration, suggesting that these non-redundant translational GTPases function in the same pathway to mitigate ribosome pausing. Ribosome stalling in the mutant brain led to activation of the integrated stress response (ISR) mediated by GCN2 and decreased mTORC1 signaling. However, in contrast to the ISR, which enhanced neuron survival, reduced mTORC1 signaling increased neuronal death. Our data demonstrate that GTPBP1 functions as an important quality control mechanism during translation elongation and suggest that translational signaling pathways intricately interact to regulate neuronal homeostasis during defective translation elongation.

2020-10-26 | GSE157902 | GEO

Multiple mechanisms activate GCN2 eIF2 kinase in response to diverse stress conditions

Project description:Diverse environmental insults induce the integrated stress response (ISR), which features eIF2 phosphorylation and translational control that serves to restore protein homeostasis. The eIF2 kinase GCN2 is a first responder in the ISR that is activated by amino acid depletion and other unrelated stresses. Two processes are suggested to trigger an ordered process of GCN2 activation during stress: GCN2 monitoring stress via accumulating uncharged tRNAs or by stalled and colliding ribosomes. Our results suggest that while ribosomal collisions are indeed essential for GCN2 activation in response to translational elongation inhibitors, conditions that trigger deacylation of tRNAs activate GCN2 via its direct association with affected tRNAs. Both process require the GCN2 regulatory domain related to histidyl tRNA synthetases. GCN2 activation by UV irradiation features lowered amino acids and increased uncharged tRNAs and ribosome collisions are dispensable. We conclude that there are multiple mechanisms that activate GCN2 during diverse stresses.

2024-03-06 | GSE239867 | GEO

ZAK activation on colliding ribosomes triggers SAPK signaling pathways to regulate cell fate

Project description:Problems arising during translation of mRNAs lead to ribosome stalling and collisions with trailing ribosomes. These collisions are known to trigger a series of events including degradation of the stalled nascent polypeptide, decay of the problematic mRNAs, and ribosome rescue. However, the systemic cellular response of ribosome collision has not been explored. Here, we uncover a novel function for ribosome collisions in signal transduction. Using multiple translation elongation inhibitors and cellular stress conditions, we show that ribosome collisions activate both the SAPK (Stress Activated Protein Kinase) and GCN2-mediated cellular stress response pathways that lead to apoptosis and the integrated stress response (ISR), respectively. We further show that the MAPKKK ZAK functions as the sentinel for ribosome collisions, and ZAK is required for activation of both SAPKs p38/JNK and GCN2 signaling pathways. Selective ribosome profiling and biochemistry demonstrate that ZAK preferentially associates with the minimal unit of colliding ribosomes, the disome, inducing ZAK phosphorylation. While ZAK associates with elongating ribosomes under non-stressed conditions, activation of ZAK is specifically trigger by colliding ribosomes. Together, these results provide new insights into how perturbation of translational homeostasis, as read-out by colliding ribosomes, regulates cell fate.

2020-08-18 | GSE141459 | GEO

The ribosome collision sensor Hel2 functions as preventive quality control in the secretory pathway

Project description:The ribosome collision due to translational stalling is recognized as a problematic event in translation by E3 ubiquitin ligase Hel2, leading to the non-canonical subunit dissociation followed by targeting of the faulty nascent peptides for degradation. Although Hel2-mediated quality control greatly contributes to maintaining cellular protein homeostasis, its physiological role in dealing with endogenous substrates remains unclear. Here we present a genome-wide analysis, based on selective ribosome profiling, to survey the endogenous substrates for Hel2. This reveals that Hel2 preferentially binds to the pre-engaged secretory ribosome-nascent-chain complexes (RNCs), which is translating upstream of targeting signals. Notably, Hel2 recruitment into secretory RNCs is elevated in the SRP-deficient condition; furthermore, the mitochondrial defects caused by insufficient SRP are enhanced by hel2 deletion, together with the mistargeting of secretory proteins into mitochondria. Collectively, our findings provide novel insights into the risk management in the secretory pathway for maintaining the cellular protein homeostasis.

2021-03-23 | GSE156535 | GEO

Examination of gene expression in cerebellum of mouse strains B6J, B6J-nmf205-/-, B6J-Gcn2-/- and B6J-nmf205-/-;Gcn2-/-.

Project description:Ribosome stalling during translation has recently been shown to cause neurodegeneration, yet the signaling pathways triggered by stalled elongation complexes are unknown. To investigate these pathways we analyzed the brain of B6J-nmf205-/- mice in which neuronal elongation complexes are stalled at AGA codons due to deficiencies in a tRNA Arg(UCU) tRNA and GTPBP2, a mammalian ribosome rescue factor. Increased levels of phosphorylation of eIF2α (Ser51) were detected prior to neurodegeneration in these mice and transcriptome analysis demonstrated activation of ATF4, a key transcription factor in the integrated stress response (ISR) pathway. Genetic experiments showed that this pathway was activated by the eIF2α kinase, GCN2, in an apparent deacylated tRNA-independent fashion. Further we found that the ISR attenuates neurodegeneration in B6J-nmf205-/- mice, underscoring the importance of cellular and stress context on the outcome of activation of this pathway. These results demonstrate the critical interplay between translation elongation and initiation in regulating neuron survival during cellular stress.

2016-06-15 | GSE79929 | GEO

Examination of gene expression in cerebellum and hippocampus for mouse C57BL/6J WT and nmf205-/-

Project description:Ribosome stalling during translation has recently been shown to cause neurodegeneration, yet the signaling pathways triggered by stalled elongation complexes are unknown. To investigate these pathways we analyzed the brain of B6J-nmf205-/- mice in which neuronal elongation complexes are stalled at AGA codons due to deficiencies in a tRNA Arg(UCU) tRNA and GTPBP2, a mammalian ribosome rescue factor. Increased levels of phosphorylation of eIF2α (Ser51) were detected prior to neurodegeneration in these mice and transcriptome analysis demonstrated activation of ATF4, a key transcription factor in the integrated stress response (ISR) pathway. Genetic experiments showed that this pathway was activated by the eIF2α kinase, GCN2, in an apparent deacylated tRNA-independent fashion. Further we found that the ISR attenuates neurodegeneration in B6J-nmf205-/- mice, underscoring the importance of cellular and stress context on the outcome of activation of this pathway. These results demonstrate the critical interplay between translation elongation and initiation in regulating neuron survival during cellular stress.

2016-06-15 | GSE79926 | GEO

Molecular interactions between Hel2 and RNA supporting ribosome-associated quality control [II]

Project description:Ribosome-associated quality control (RQC) pathways monitor and respond to stalling of translating ribosomes. Using a newly developed technique based on in vivo UV crosslinking and mass spectrometry, we identify a C-terminal region in Hel2/Rqt1 as an RNA binding domain, with amino acids L501/K502 directly interacting with RNA. In vivo crosslinking of Hel2 revealed binding to 18S rRNA and translating mRNAs. Consistent with the 18S binding site located between mRNA entrance and exit channels, Hel2 preferentially bound mRNA both upstream and downstream of the termination codon. A C-terminal truncation that deleted L501/K502, abolished crosslinking to 18S rRNA, altered mRNA binding patterns, and reduced Hel2 function comparable to hel2∆. Asc1, also participates in RQC and ASC1 deletion impaired Hel2 18S and mRNA binding. We conclude that Hel2 is recruited or stabilized on translating 40S ribosomal subunits by interactions with 18S rRNA and Asc1. Ribosome-bound Hel2 interacts with mRNA, predominately during translation termination.

2019-01-18 | GSE114420 | GEO

Molecular interactions between Hel2 and RNA supporting ribosome-associated quality control [I]

2019-01-18 | GSE114415 | GEO