Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA151551 | ENA |
REPOSITORIES: ENA
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Project description:Limitation of essential amino acids, such as tyrosine or methionine/cysteine, causes upregulation of exogenous integrated transgene expression in mammalian cells. This phenomenon is mediated by histone acetylation and chromatin remodelling, since histone deacetylase (HDAC) inhibitors reproduce starvation-induced transgene upregulation and chromatin immunoprecipitation analysis of amino acid-deprived cells reveals significant changes in total core histones detectable at the CMV promoter. Expression profiling of HeLa cells starved for 5 days in medium without tyrosine or methionine/cysteine provides important information on the cellular response to amino acid deprivation and suggests the involvement of HDAC4 (class II HDAC) in transgene derepression during amino acid starvation. Total RNA obtained from HeLa and HeLaOA1myc cells (HeLa cells with a human ocular albinism type 1 (OA1)+myc tag transgene) subjected to 5 days of tyrosine or methionine/cysteine starvation compared to control cells. Twelve samples are analyzed: HeLa and HeLaOA1myc grown for 5 days in RPMI deprived of tyrosine (Y) vs. complete RPMI; technical duplicates of HeLa and HeLaOA1myc grown for 5 days in DMEM deprived of methionine/cysteine (MC) vs. complete DMEM.
2012-07-23 | E-GEOD-35323 | biostudies-arrayexpress
Project description:Limitation of essential amino acids, such as tyrosine or methionine/cysteine, causes upregulation of exogenous integrated transgene expression in mammalian cells. This phenomenon is mediated by histone acetylation and chromatin remodelling, since histone deacetylase (HDAC) inhibitors reproduce starvation-induced transgene upregulation and chromatin immunoprecipitation analysis of amino acid-deprived cells reveals significant changes in total core histones detectable at the CMV promoter. Expression profiling of HeLa cells starved for 5 days in medium without tyrosine or methionine/cysteine provides important information on the cellular response to amino acid deprivation and suggests the involvement of HDAC4 (class II HDAC) in transgene derepression during amino acid starvation.
2012-07-24 | GSE35323 | GEO
Project description:We have previously shown that deprivation of essential amino acids, namely methionine/cysteine or tyrosine, leads to the transcriptional reactivation of integrated silenced transgenes, and latent HIV-1 provirus. In an effort to understand the underlying mechanisms, here we investigate the overall transcriptional profile of HeLa cells upon Met/Cys starvation for different time points, including the expression of repeated and transposable elements. HeLa cells carrying a stably integrated and silenced plasmid expressing the OA1/GPR143 gene (pcDNA3.1-OA1) were cultured in regular DMEM medium for 6-30-120 hours, or in absence of Met/Cys for 6-15-30-72-120 hours, and the changes in the expression of genes and repeated elements was evaluated by RNAseq
2018-07-21 | E-MTAB-6452 | biostudies-arrayexpress
Project description:Transcriptome analysis of HeLa cells upon deprivation of methionine and cysteine (Met/Cys)
| PRJEB24740 | ENA
Project description:First experiment: Cells were cultured in sulfur amino acid-free DMEM supplemented with 0.1 mM methionine + 0.1 mM cysteine (complete) or supplemented only with 0.1 mM methionine (cysteine-free). Cells were cultured in either medium for 42 h (Long + Cys; Long -Cys) or in cysteine-free medium for 36 h followed by 6 h in complete medium (Short +Cys) Second experiment: C3A/HepG2 cells were cultured in sulfur amino acid-free DMEM supplemented with 0.1 mM Met and 0.1 mM Cys (complete) or supplemented only with 0.1 mM Met (cysteine-devoid). Cells were cultured in complete medium for 42 h (Long +Cys) or in complete medium for 36 h followed by cysteine-devoid medium for 6 h (Short -Cys). Keywords: amino acid deprivation
2007-12-13 | GSE9517 | GEO
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
2010-09-25 | GSE24338 | GEO
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
| S-EPMC2531291 | biostudies-literature
Project description:Besides being building blocks for protein synthesis, amino acids serve a wide variety of cellular functions, including acting as metabolic intermediates for ATP generation and for redox homeostasis. Upon amino acid deprivation, free uncharged tRNAs trigger GCN2-ATF4 to mediate the well-characterized transcriptional amino acid response (AAR). However, it is not clear whether the deprivation of different individual amino acids triggers identical or distinct AARs. Here, we characterized the global transcriptional response upon deprivation of one amino acid at a time. With the exception of glycine, which was not required for the proliferation of MCF7 cells, we found that the deprivation of most amino acids triggered a shared transcriptional response that included the activation of ATF4, p53 and TXNIP. However, there was also significant heterogeneity among different individual AARs. The most dramatic transcriptional response was triggered by methionine deprivation, which activated an extensive and unique response in different cell types. We uncovered that the specific methionine-deprived transcriptional response required creatine biosynthesis. This dependency on creatine biosynthesis was caused by the consumption of S-Adenosyl-L-methionine (SAM) during creatine biosynthesis that helps to deplete SAM under methionine deprivation and reduces histone methylations. As such, the simultaneous deprivation of methionine and sources of creatine biosynthesis (either arginine or glycine) abolished the reduction of histone methylation and the methionine-specific transcriptional response. Arginine-derived ornithine was also required for the complete induction of the methionine-deprived specific gene response. Collectively, our data identify a previously unknown set of heterogeneous amino acid responses and reveal a distinct methionine-deprived transcriptional response that results from the crosstalk of arginine, glycine and methionine metabolism via arginine/glycine-dependent creatine biosynthesis. RNA was extracted by RNAeasy kits (Qiagen) from the MCF7 or PC3 cells which exposed to the control full DMEM or deprived one (or all) amino acid media for 24 or 48 hours.
2015-04-01 | E-GEOD-62673 | biostudies-arrayexpress
Project description:RNA extracted at 240min. Samples are rRNA depleted. Expression measurement of Homo sapiens genes.
2019-07-31 | GSE114179 | GEO