Survival and Proliferation of T-cell Acute Lymphoblastic Leukaemia Depends on mTOR-regulated Glutamine Uptake and EAAT1 Activity
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE101566 | GEO | 2020/11/01
REPOSITORIES: GEO
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Project description:Nucleosomes are decorated with numerous post-translational modifications capable of influencing many DNA processes. Here, we describe a new class of modification, methylation of glutamine, occurring on yeast histone H2A at position 105 (Q105) and human H2A at Q104. We identify Nop1 as the methyltransferase in yeast and we demonstrate that Fibrillarin is the equivalent enzyme in human cells. Glutamine methylation of H2A is restricted to the nucleolus. Global analysis in yeast, using a H2AQ105me specific antibody, show that this modification is exclusively enriched over the 35S rDNA transcriptional unit. We show that the Q105 residue is part of the binding site for the histone chaperone FACT (Facilitator of Transcription) complex. Methylation of Q105 or its substitution to alanine disrupts binding to FACT in vitro. A yeast strain mutated at Q105 exhibits a defect in histone incorporation and shows increased transcription at rDNA genes. This defect is phenocopied by mutations in FACT that decrease its activity. Together these data identify glutamine methylation of H2A as the first histone epigenetic mark dedicated to a specific RNA polymerase and define its function as a regulator of FACT interaction with nucleosomes.
2014-01-21 | E-MTAB-1447 | biostudies-arrayexpress
Project description:The PI3K-PKB/c-akt-FOXO signalling network provides a major intracellular hub for regulation of cell proliferation, survival and stress resistance1. Here we report a novel function for FOXO transcription factors in regulating autophagy through modulation of intracellular glutamine levels. To identify novel transcriptional targets of this module we performed an unbiased microarray analysis after conditional activation of the key components PI3K, PKB, FOXO3 and FOXO4. Utilising this global pathway approach we identified glutamine synthetase (GS) as being transcriptionally regulated by PI3K-PKB-FOXO signalling. FOXO-mediated increase in GS expression specifically induced glutamine production independently of cell type, and this was evolutionary conserved. FOXO activation resulted in mTOR inhibition by preventing the translocation of mTOR to lysosomal membranes, which was dependent on GS activity. Increased GS activity resulted in increased autophagosome turnover as measured by LC3 lipidation, p62 degradation, and confocal imaging of LC3, p62, WIPI-1, ULK2 and Atg12. Inhibition of FOXO3-mediated autophagy resulted in increased apoptosis, suggesting that the induction of autophagy by FOXO3-mediated upregulation of GS is important for cellular survival. These findings reveal a novel signalling network that can directly modulate autophagy through regulation of glutamine metabolism. conditional activation of pkb and pi3k were followed in a timeseries. Each timepoint consists of 4 independent replicates, labeled with either cy3 or cy5 and put on array against time0.
2012-07-21 | E-GEOD-35701 | biostudies-arrayexpress
Project description:The PI3K-PKB/c-akt-FOXO signalling network provides a major intracellular hub for regulation of cell proliferation, survival and stress resistance1. Here we report a novel function for FOXO transcription factors in regulating autophagy through modulation of intracellular glutamine levels. To identify novel transcriptional targets of this module we performed an unbiased microarray analysis after conditional activation of the key components PI3K, PKB, FOXO3 and FOXO4. Utilising this global pathway approach we identified glutamine synthetase (GS) as being transcriptionally regulated by PI3K-PKB-FOXO signalling. FOXO-mediated increase in GS expression specifically induced glutamine production independently of cell type, and this was evolutionary conserved. FOXO activation resulted in mTOR inhibition by preventing the translocation of mTOR to lysosomal membranes, which was dependent on GS activity. Increased GS activity resulted in increased autophagosome turnover as measured by LC3 lipidation, p62 degradation, and confocal imaging of LC3, p62, WIPI-1, ULK2 and Atg12. Inhibition of FOXO3-mediated autophagy resulted in increased apoptosis, suggesting that the induction of autophagy by FOXO3-mediated upregulation of GS is important for cellular survival. These findings reveal a novel signalling network that can directly modulate autophagy through regulation of glutamine metabolism. conditional activation of foxo3 and foxo4 were followed in a timeseries. Each timepoint consists of 4 independent replicates, labeled with either cy3 or cy5 and put on array against time0 as reference.
2012-07-21 | E-GEOD-35703 | biostudies-arrayexpress
Project description:The PI3K-PKB/c-akt-FOXO signalling network provides a major intracellular hub for regulation of cell proliferation, survival and stress resistance1. Here we report a novel function for FOXO transcription factors in regulating autophagy through modulation of intracellular glutamine levels. To identify novel transcriptional targets of this module we performed an unbiased microarray analysis after conditional activation of the key components PI3K, PKB, FOXO3 and FOXO4. Utilising this global pathway approach we identified glutamine synthetase (GS) as being transcriptionally regulated by PI3K-PKB-FOXO signalling. FOXO-mediated increase in GS expression specifically induced glutamine production independently of cell type, and this was evolutionary conserved. FOXO activation resulted in mTOR inhibition by preventing the translocation of mTOR to lysosomal membranes, which was dependent on GS activity. Increased GS activity resulted in increased autophagosome turnover as measured by LC3 lipidation, p62 degradation, and confocal imaging of LC3, p62, WIPI-1, ULK2 and Atg12. Inhibition of FOXO3-mediated autophagy resulted in increased apoptosis, suggesting that the induction of autophagy by FOXO3-mediated upregulation of GS is important for cellular survival. These findings reveal a novel signalling network that can directly modulate autophagy through regulation of glutamine metabolism.
2012-07-22 | GSE35703 | GEO
Project description:The PI3K-PKB/c-akt-FOXO signalling network provides a major intracellular hub for regulation of cell proliferation, survival and stress resistance1. Here we report a novel function for FOXO transcription factors in regulating autophagy through modulation of intracellular glutamine levels. To identify novel transcriptional targets of this module we performed an unbiased microarray analysis after conditional activation of the key components PI3K, PKB, FOXO3 and FOXO4. Utilising this global pathway approach we identified glutamine synthetase (GS) as being transcriptionally regulated by PI3K-PKB-FOXO signalling. FOXO-mediated increase in GS expression specifically induced glutamine production independently of cell type, and this was evolutionary conserved. FOXO activation resulted in mTOR inhibition by preventing the translocation of mTOR to lysosomal membranes, which was dependent on GS activity. Increased GS activity resulted in increased autophagosome turnover as measured by LC3 lipidation, p62 degradation, and confocal imaging of LC3, p62, WIPI-1, ULK2 and Atg12. Inhibition of FOXO3-mediated autophagy resulted in increased apoptosis, suggesting that the induction of autophagy by FOXO3-mediated upregulation of GS is important for cellular survival. These findings reveal a novel signalling network that can directly modulate autophagy through regulation of glutamine metabolism.
2012-07-22 | GSE35701 | GEO
Project description:Survival and Proliferation of T-cell Acute Lymphoblastic Leukaemia Depends on mTOR-regulated Glutamine Uptake and EAAT1 Activity
| PRJNA394841 | ENA
Project description:To understand the effects of glutamine deprivation on cell physiology we performed global analysis of gene expression in response to glutamine deprivation. U2OS cells were subjected to glutamine deprivation for 24h followed by RNA extraction and microarray analysis.
2014-07-31 | GSE59931 | GEO
Project description:To understand the effects of glutamine deprivation on cell physiology we performed global analysis of gene expression in response to glutamine deprivation. U2OS cells were subjected to glutamine deprivation for 24h followed by RNA extraction and microarray analysis. U2OS cells were plated overnight followed by treatment for 24h with glutamine-containing and glutamine-depleted media. Three biological replicates were assayed for each condition.
2014-07-31 | E-GEOD-59931 | biostudies-arrayexpress
Project description:Decreasing glucagon action lowers blood glucose and may be a useful therapeutic approach for diabetes. However, interrupted glucagon signaling in mice leads to hyperglucagonemia and α-cell hyperplasia. We show using islet transplantation, mouse and zebrafish models, an in vitro islet culture assay that a hepatic-derived, circulating factor in mice with interrupted glucagon signaling stimulates α-cell proliferation, which was dependent on mTOR signaling and the FoxP transcription factors. α-cells of transplanted human islets also proliferated in response to this signal in mice. A combination of liver transcriptomics and serum fractionation with proteomics/metabolomics found changes in hepatic gene expression relating to amino acid catabolism predicting the observed increase in serum amino acid levels. Amino acid concentrations that mimicked the levels in mice with interrupted glucagon signaling, specifically L-glutamine, stimulated α-cell proliferation. These results indicate a hepatic-α-islet cell axis where glucagon regulates serum amino acid availability and L-glutamine regulates α-cell proliferation via mTOR-dependent nutrient sensing.
2017-03-31 | GSE89035 | GEO
Project description:Objective: Insulin regulates amino acid metabolism. We investigated whether glycemia and 43 genetic risk variants for hyperglycemia/type 2 diabetes affect amino acid levels in a large population-based cohort. Subjects and Methods: A total of 9,371 non-diabetic or newly-diagnosed type 2 diabetic Finnish men from the population-based METSIM Study were studied. Proton NMR spectroscopy was used to measure plasma levels of 8 amino acids. Genotyping of 42 SNPs and mRNA microarray analysis from 200 subcutaneous adipose tissue samples were performed. Results: Increasing fasting and/or 2-hour plasma glucose levels were associated with increasing levels of alanine, valine, leucine, isoleucine, phenylalanine and tyrosine, and decreasing levels of histidine and glutamine. We also found significant correlations between insulin sensitivity (Matsuda ISI) and expression of genes regulating amino acid metabolism. Only one SNP (rs780094 in GCKR) of the 42 risk SNPs for type 2 diabetes or hyperglycemia was significantly associated with the levels of alanine, isoleucine, and glutamine. Conclusions : We observed that the levels of branched-chain, aromatic amino acids and alanine increased and the levels of glutamine and histidine decreased with increasing glycemia. These associations seemed to be mediated by insulin resistance, at least in part. GCKR rs780094 was significantly associated with several amino acids. Total RNA was obtained from subcutaneous fat biopsies from 200 people participating in the METSIM study (4 samples were replicated for a total of 204 arrays).
2012-04-01 | E-GEOD-32512 | biostudies-arrayexpress