Assessment of mTOR-Dependent Translational Regulation of Interferon Stimulated Genes
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE70270 | GEO | 2015/07/07
SECONDARY ACCESSION(S): PRJNA288136
REPOSITORIES: GEO
Similar Datasets
Project description:mTOR regulates mRNA translation. Whereas ribosome-profiling suggested that mTOR exclusively stimulates translation of TOP (containing a 5â-terminal oligopyrimidine [5âTOP] motif) and TOP-like mRNAs, polysome-profiling implied that mTOR also modulates translation of non-TOP mRNAs. We show that ribosome-, but not polysome-profiling, is biased towards identification of TOP mRNAs as differentially translated while obscuring detection of changes in non-TOP mRNA translation. Transcription start site profiling by Nano-Cap Analysis of Gene Expression (nanoCAGE) revealed that many mTOR-sensitive mRNAs do not have 5âTOP motifs. Moreover, nanoCAGE showed that 5â UTR features distinguish two functionally and translationally distinct subsets of mTOR-sensitive mRNAs: i) those with short 5â UTRs enriched for mitochondrial functions such as respiration, that are translated in an eIF4E, but not eIF4A1-dependent manner and ii) mRNAs encoding proliferation- and survival-promoting proteins, that harbor long 5â UTRs, and require both eIF4E and eIF4A1 for their efficient translation. Selective inhibition of translation of mRNAs harboring long 5â UTRs via suppression of eIF4A leads to uncoupling of expression of proteins involved in respiration (e.g. ATP5O) from those protecting mitochondrial integrity (e.g. BCL-2) ultimately resulting in apoptosis. Conversely, simultaneous translational downregulation of both long and short 5â UTR mRNAs by mTOR inhibitors results in suppression of mitochondrial respiration and predominantly cytostatic effects. Therefore, 5â UTR features define differential modes of translation of functionally distinct mTOR-sensitive mRNAs, which explains discrepancies between the effects of mTOR and eIF4A inhibitors on neoplastic cells. Determination of 5'UTR lengths using nanoCAGE in MCF7 cells
2016-03-14 | E-GEOD-77033 | biostudies-arrayexpress
Project description:mTOR regulates mRNA translation. Whereas ribosome-profiling suggested that mTOR exclusively stimulates translation of TOP (containing a 5’-terminal oligopyrimidine [5’TOP] motif) and TOP-like mRNAs, polysome-profiling implied that mTOR also modulates translation of non-TOP mRNAs. We show that ribosome-, but not polysome-profiling, is biased towards identification of TOP mRNAs as differentially translated while obscuring detection of changes in non-TOP mRNA translation. Transcription start site profiling by Nano-Cap Analysis of Gene Expression (nanoCAGE) revealed that many mTOR-sensitive mRNAs do not have 5’TOP motifs. Moreover, nanoCAGE showed that 5’ UTR features distinguish two functionally and translationally distinct subsets of mTOR-sensitive mRNAs: i) those with short 5’ UTRs enriched for mitochondrial functions such as respiration, that are translated in an eIF4E, but not eIF4A1-dependent manner and ii) mRNAs encoding proliferation- and survival-promoting proteins, that harbor long 5’ UTRs, and require both eIF4E and eIF4A1 for their efficient translation. Selective inhibition of translation of mRNAs harboring long 5’ UTRs via suppression of eIF4A leads to uncoupling of expression of proteins involved in respiration (e.g. ATP5O) from those protecting mitochondrial integrity (e.g. BCL-2) ultimately resulting in apoptosis. Conversely, simultaneous translational downregulation of both long and short 5’ UTR mRNAs by mTOR inhibitors results in suppression of mitochondrial respiration and predominantly cytostatic effects. Therefore, 5’ UTR features define differential modes of translation of functionally distinct mTOR-sensitive mRNAs, which explains discrepancies between the effects of mTOR and eIF4A inhibitors on neoplastic cells.
2016-03-14 | GSE77033 | GEO
Project description:Sensitivity to Interferon (IFN) is determined by a complex coordination of genetic and environmental factors. A previous experiment using two renal cancer cell lines differing markedly in their response to IFN were analyzed for their ISG profiles in order to determine gene expression changes associated with IFN sensitivity (Holko M, Williams BR. Functional annotation of IFN-alpha-stimulated gene expression profiles from sensitive and resistant renal cell carcinoma cell lines. J Interferon Cytokine Res 2006 Aug;26(8):534-47). Higher and more persistent expression of a subset of ISGs was noted in the IFN-sensitive RCC1 cells when compared with the relatively IFN-insensitive ACHN cells. A subset of Interferon stimulated genes (ISGs) whose sustained expression correlates with heightened IFN sensitivity were analyzed for functional and sequence similarities. This subset predominately contains genes involved in transcription, and most were found to contain in their promoters binding sites for promyleocytic zinc finger factor (PLZF), a transcriptional repressor identified by virtue of its role in the etiology of Acute Promyelocytic Leukemia (APL). Analysis of gene expression in a lymphoid cell line with inducible PLZF expression reveals that increased expression of immune system related genes including ISGs, depends on PLZF expression. Chromatin Immunoprecipitation assays show direct association between PLZF and in silico identified PLZF binding sites in ISG promoters. This study reveals a novel interaction between PLZF and IFN signaling. A time course of IFNa treatment (0, 6, 16, 24 hrs) was performed in tetetracycline induced PLZF overexpressing and control U937T:PLZF45 cells. For the 0 hr time point, PLZF overexpression (Cy5) was compared with control cells (Cy3). For the 6, 16, and 24 hr IFN treated time points, treated RNA was labelled with Cy5 and non-IFN treated RNA with Cy3. Each IFN treatment time point was performed on control and PLZF-overexpressing cells respectively.
2010-05-18 | E-GEOD-16196 | biostudies-arrayexpress
Project description:Interferons (IFNs) play a major role in controlling viral infections including HIV/SIV infections. Persistent up-regulation of interferon stimulated genes (ISGs) is associated with chronic immune activation and progression in SIV/HIV infections, but the respective contribution of different IFNs is unclear. We analyzed the expression of IFN genes and ISGs in tissues of SIV infected macaques to understand the respective roles of type I and type II IFNs. Both IFN types were induced in lymph nodes during early stage of primary infection and to some extent in rectal biopsies but not in PBMCs. Induction of Type II IFN expression persisted during the chronic phase, in contrast to undetectable induction of type I IFN expression. Global gene expression analysis with a major focus on ISGs revealed that at both acute and chronic infection phases most differentially expressed ISGs were inducible by both type I and type II IFNs and displayed the highest increases, indicating strong convergence and synergy between type I and type II IFNs. These results suggest that IFN- strongly contribute to shape ISG upregulation in addition to type I IFN. The analysis of functional signatures of ISG expression revealed temporal changes in IFN expression patterns identifying phasespecific ISGs.
2017-10-30 | E-MTAB-6068 | biostudies-arrayexpress
Project description:Translation of TOP mRNAs encoding protein synthesis machinery is strictly regulated by an amino acid sensing mTOR pathway. However, its regulatory mechanism remains elusive. Here, we demonstrate that TOP mRNA translation positively correlates with its poly(A) tail length under mTOR active/amino acid-rich condition, suggesting that TOP mRNAs are post-transcriptionally controlled by poly(A) tail length regulation. Consistent with this, tail length of TOP mRNAs dynamically fluctuates in response to amino acid availability. Poly(A) tail shortens under mTOR active/ amino acid-rich condition, whereas the long-tailed TOP mRNAs accumulate under mTOR inactive/amino acid-starved (AAS) condition. An RNA-binding protein LARP1 that specifically binds to TOP mRNAs is indispensable for the process. We also show that LARP1 interacts with non-canonical poly(A) polymerases, PAPD4, PAPD5 and PAPD7 and induces post-transcriptional polyadenylation of the target when tethered to the mRNA. Our findings illustrate that LARP1 contributes to the selective accumulation of TOP mRNAs with long poly(A) tail under AAS, resulting in accelerated ribosomal loading onto TOP mRNAs for the resumption of translation after AAS.
2022-09-22 | GSE145744 | GEO
Project description:Translation of TOP mRNAs encoding protein synthesis machinery is strictly regulated by an amino acid sensing mTOR pathway. However, its regulatory mechanism remains elusive. Here, we demonstrate that TOP mRNA translation positively correlates with its poly(A) tail length under mTOR active/amino acid-rich condition, suggesting that TOP mRNAs are post-transcriptionally controlled by poly(A) tail length regulation. Consistent with this, tail length of TOP mRNAs dynamically fluctuates in response to amino acid availability. Poly(A) tail shortens under mTOR active/ amino acid-rich condition, whereas the long-tailed TOP mRNAs accumulate under mTOR inactive/amino acid-starved (AAS) condition. An RNA-binding protein LARP1 that specifically binds to TOP mRNAs is indispensable for the process. We also show that LARP1 interacts with non-canonical poly(A) polymerases, PAPD4, PAPD5 and PAPD7 and induces post-transcriptional polyadenylation of the target when tethered to the mRNA. Our findings illustrate that LARP1 contributes to the selective accumulation of TOP mRNAs with long poly(A) tail under AAS, resulting in accelerated ribosomal loading onto TOP mRNAs for the resumption of translation after AAS.
2022-09-19 | GSE137807 | GEO
Project description:The antiproliferative, antiviral, and immunomodulatory properties of interferons (IFNs) have led to its therapeutic implementation. IFNs effects are mediated by a complex network of signal transducers, culminating in IFN-stimulated gene (ISG) induction. This complexity leads to diverse clinical responses to IFN, from no response to complete regression of disease. Elucidation of ISG induction patterns is, therefore, essential to understand and maximize its therapeutic potential. To correlate ISG expression profiles with IFN responsiveness, two renal cell carcinoma (RCC) cell lines differing in antiviral and apoptotic response to IFN were treated with IFN-alpha for different times, and expression profiles were analyzed using a customized microarray containing 850 unique putative ISGs. Genes with similar kinetics of induction in both cell lines were clustered and analyzed for gene function. Seven sets of coordinately regulated genes were identified by k-means cluster analysis, and significant functional similarities were identified for five of the seven sets. Strikingly, expression of genes associated with transcription temporally preceded expression of those involved in signal transduction. Enhanced antiviral sensitivity to IFN was coincident with sustained expression of ISGs involved in transcriptional regulation. However, no difference in Stat1 activation was observed between the cell lines. Analysis of ISG expression patterns suggests that subtle differences in transcription profiles contribute to differences in IFN responsiveness. Two human renal cell carcinoma cell lines (ACHN and RCC1) were treated with IFN-alpha for 3, 6, 9, 12, 16, and 24 hours. Total RNA from treated cells (Cy5) is hybridized with total RNA from untreated control cells (Cy3) to the custom ISG 1.3.1 cDNA array.
2010-05-18 | E-GEOD-15193 | biostudies-arrayexpress
Project description:Sensitivity to Interferon (IFN) is determined by a complex coordination of genetic and environmental factors. A previous experiment using two renal cancer cell lines differing markedly in their response to IFN were analyzed for their ISG profiles in order to determine gene expression changes associated with IFN sensitivity (Holko M, Williams BR. Functional annotation of IFN-alpha-stimulated gene expression profiles from sensitive and resistant renal cell carcinoma cell lines. J Interferon Cytokine Res 2006 Aug;26(8):534-47). Higher and more persistent expression of a subset of ISGs was noted in the IFN-sensitive RCC1 cells when compared with the relatively IFN-insensitive ACHN cells. A subset of Interferon stimulated genes (ISGs) whose sustained expression correlates with heightened IFN sensitivity were analyzed for functional and sequence similarities. This subset predominately contains genes involved in transcription, and most were found to contain in their promoters binding sites for promyleocytic zinc finger factor (PLZF), a transcriptional repressor identified by virtue of its role in the etiology of Acute Promyelocytic Leukemia (APL). Analysis of gene expression in a lymphoid cell line with inducible PLZF expression reveals that increased expression of immune system related genes including ISGs, depends on PLZF expression. Chromatin Immunoprecipitation assays show direct association between PLZF and in silico identified PLZF binding sites in ISG promoters. This study reveals a novel interaction between PLZF and IFN signaling.
2009-05-22 | GSE16196 | GEO
Project description:Type I interferons (IFN-I) are critical in antimicrobial and antitumor defense. Although IFN-I signal via the interferon-stimulated gene factor 3 (ISGF3) complex consisting of STAT1, STAT2 and IRF9, IFN-I can mediate significant biological effects via ISGF3-independent pathways. For example, absence of STAT1, STAT2 or IRF9 exacerbates neurological disease in transgenic mice with CNS-production of IFN-gamma. Here we determined the role of IFN-I-driven, ISGF3-independent signaling in regulating global gene expression in STAT1, STAT2 or IRF9-deficient murine mixed glial cell cultures (MGCs). Compared with WT, the expression of IFN-gamma-stimulated genes (ISGs) was reduced in number and magnitude in MGCs that lacked STAT1, STAT2 or IRF9. There were significantly fewer ISGs in the absence of STAT1 or STAT2 versus the absence of IRF9. The majority of ISGs regulated in the STAT1-, STAT2- or IRF9-deficient MGCs individually were shared with WT. However, only a minor number of ISGs were common to WT, STAT1-, STAT2- and IRF9-deficient MGCs. While signal pathway activation in response to IFN-gamma was rapid and transient in WT MGCs, this was delayed and prolonged and correlated with increased numbers of ISGs expressed at 12 h versus 4 h IFN-gamma exposure in all three IFN-I-signaling-deficient MGCs. In conclusion, (1) IFN-I can mediate ISG expression in MGCs via ISGF3-independent signaling pathways but with reduced efficiency, with delayed and prolonged kinetics and is more dependent on STAT1 and STAT2 than IRF9, and (2) signaling pathways not involving STAT1, STAT2 or IRF9 play a minor role only in mediating ISG expression in MGCs.
2017-02-15 | E-MTAB-5445 | biostudies-arrayexpress
Project description:Recent identification of IL28B gene polymorphisms associated with hepatitis C virus (HCV) clearance suggests a role for type III interferons (IFNs) in hepatitis C infection. The function of type III IFNs in intrinsic antiviral immunity is poorly understood. Here we show that HCV infection of primary human hepatocytes results in a robust induction of type III but not type I IFNs, leading to IFN- stimulated gene (ISG) expression. In addition, HCV infection elicits a much broader range of gene expression alterations in addition to ISG induction. The induction of type III IFNs is mediated by IRF3 and NFkB- dependent pathways. Type III IFN, aside from upregulating ISGs with a different kinetic profile, induces a distinct set of genes from type I IFN, potentially explaining the functional difference between the two types of IFNs. Chimpanzees undergoing experimental HCV infection demonstrated a prompt hepatic induction of IL28, associating with ISG upregulation, but minimal type I IFN induction. Analysis of liver biopsies from HCV-infected patients supported a close correlation among hepatic expression of IL28 and ISGs, but not with type I IFNs. Our study demonstrates that HCV infection results predominantly in type III IFN induction in the liver and the level of induction correlates with hepatic ISG levels, thus providing a mechanistic explanation for the association between IL28, ISG levels and recovery from HCV infection as well as a potential therapeutic strategy for the treatment of non-responders. Samples were treated with IFN, IL28b and T-PolyC after 6 or 24 hours respectively
2012-03-09 | E-GEOD-31264 | biostudies-arrayexpress