Expression analysis of Chlamydomonas reinhardtii exposed to silver
Ontology highlight
ABSTRACT:
ORGANISM(S): Chlamydomonas reinhardtii
SUBMITTER: Smitha Pillai
PROVIDER: E-GEOD-48677 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Chlamydomonas reinhardtii exposed to various concentrations of silver
2013-10-01 | GSE48677 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE30645: Expression analysis of the singlet oxygen resistant 1 (sor1) mutant GSE30646: Response of Chlamydomonas reinhardtii to different oxidative and electrophilic stress conditions Refer to individual Series
2011-07-14 | E-GEOD-30648 | biostudies-arrayexpress
Project description:The inflammatory gene response requires activation of the protein kinase TAK1, but it is currently unknown how TAK1-derived signals coordinate transcriptional programs in the genome. We determined the genome-wide binding of the TAK1-controlled NF-M-NM-:B subunit p65 in relation to active enhancers and promoters of transcribed genes by ChIP-seq experiments. Out of 35,000 active enhancer regions, 410 H3K4me1-positive enhancers show interleukin (IL)-1-induced H3K27ac and p65 binding. Inhibition of TAK1, IKK2 or depletion of p65 blocked inducible enhancer activation and gene expression. As exemplified by the CXC chemokine cluster located on chromosome 4, the TAK1-p65 pathway also regulates the recruitment kinetics of the histone acetyltransferase CBP, of NF-M-NM-:B p50 and of AP-1 transcription factors to both, promoters and enhancers. This study provides a high resolution view of epigenetic changes occurring during the IL-1 response and allows the first genome-wide identification of a novel class of inducible p65 NF-M-NM-:B-dependent enhancers in epithelial cells. Two sets of experiments were performed as biological replicate series (rep1 and rep2) each comprising of the following 4 conditions: Human epithelial KB cells were 1) left untreated or were 2) treated with Interleukin-1-alpha (10ng/M-BM-5l) for 1 hour, 3) treated for 1.5h with the TAK1 inhibitor 5Z-7-oxozeaenol (1M-BM-5M) or were 4) treated with 5Z-7-oxozeaenol for 30 minutes followed by Interleukin-1-alpha for 1 hour.
2014-12-17 | E-GEOD-64201 | biostudies-arrayexpress
Project description:Heterochromatin spreading leads to the silencing of genes within its path, and boundary elements have evolved to constrain such spreading. In fission yeast, heterochromatin at centromeres I and III is flanked by inverted repeats termed IRCs, which are required for proper boundary functions. However, the mechanisms by which IRCs prevent heterochromatin spreading are unknown. Here, we identified Bdf2, homologous to the mammalian BET family of double bromodomain proteins involved in diverse types of cancers, as a factor required for proper boundary function at IRCs. Bdf2 is enriched at IRCs through its interaction with the boundary protein Epe1. The bromodomains of Bdf2 recognize acetylated histone H4 tails and antagonize Sir2-mediated deacetylation of histone H4K16 to prevent heterochromatin spreading. Our results thus illustrate a mechanism of establishing chromosome boundaries at specific sites through the recruitment of a factor that protects euchromatic histone modifications. They also reveal a previously unappreciated function of H4K16 acetylation, which cooperates with H3K9 methylation to regulate heterochromatin spreading. Two samples, H4K16ac & Bdf2-Flag
2013-09-24 | E-GEOD-46430 | biostudies-arrayexpress
Project description:Acclimation to singlet oxygen was shown to induce various oxidative stress response genes of which some were also strongly overexpressed in the singlet oxygen resistant mutant sor1. Because sor1 was also more tolerant to other oxidative and electrophilic stress conditions, and because many of the sor1 overexpressed genes are known to be involved in the detoxification of reactive electrophile species, the response of the C. reinhardtii wild-type strain to various oxidative and electrophilic stress conditions was determined. Therefore, cultures were exposed to the reactive oxygen species-producing photosensitizer neutral red, the organic hydroperoxide tert-butylhydroperoxide, the photosynthetic herbicide 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB) and the lipophilic electrophile 2(E)-Hexenal for two hours and the global genetic response was analyzed. Cluster analysis revealed the most similar expression pattern between DBMIB and 2(E)-Hexenal and to a lower degree between NR and tBOOH. Still, there were many common induced genes including several of the oxidative stress response and detoxification genes overexpressed in the sor1 mutant. The 4A+ wild-type strain was grown mixotrophically in a Tris-acetate phosphate to a density of 2x10^6 cells/ml. Then cultures were split into 20 ml subcultures, and exposed to either of the four chemicals DBMIB (2 µM), 2(E)-Hexenal (0.3 mM), neutral red (NR, 3 µM), tert-butylhydroperoxide (tBOOH, 100 µM) or no chemical (control) for 2 hours, in three independent biological replicates. The cells of each replicate were harvested by centrifugation and total RNA was isolated using the RNeasy Mini Kit (Qiagen). DNA microarrays were performed using the ‘One-Color Microarray-Based Gene Expression Analysis’ system and a custom made 4 × 44 K ‘Chlamydomonas Whole Genome DNA Microarrays’ (Agilent Technologies) containing 15143 specific probes designed based on the Chlamydomonas version 4.0 transcript models provided by the DOE Joint Genome Institute (JGI), with an average of three replicates for each probe
2011-07-14 | E-GEOD-30646 | biostudies-arrayexpress
Project description:Our microarray study validates characteristic functions of serrated adenocarcinoma (SAC) reported in the only previous study which was performed on patients from a dissimilar environmental and genetic background and using a different microarray platform. In our study, fascin1 and hippocalcin were validated at the mRNA and protein level as the best biomarkers reported so far for the distinction of SAC from conventional carcinoma and from colorectal carcinoma showing molecular and histological features of high-level microsatellite instability. In this study, we used gene expression arrays to investigate differences between two experimental classes: serrated and conventional carcinomas
2012-10-31 | E-GEOD-36758 | biostudies-arrayexpress
Project description:To identify components involved in the signal transduction and activation of the singlet oxygen-mediated response, a mutant selection was performed. This led to the isolation of the singlet oxygen resistant 1 (sor1) mutant, which is more tolerant to singlet oxygen-producing chemicals and shows a constitutively higher expression of GPXH and GSTS1. Map-based cloning revealed that the SOR1 gene encodes a novel bZIP transcription factor, which seems to control its own expression as well as that of a large number of oxidative stress response and detoxification genes. In the promoter region of many of these genes a highly conserved 8-bp palindromic sequence element was found to be enriched. This element was shown to be essential for GSTS1 overexpression in sor1 and for induction by increased levels of lipophilic reactive electrophile species (RES) suggesting that it functions as an electrophile response element (ERE). RES can be formed after singlet oxygen-induced lipid peroxidation, indicating that a RES-stimulated and SOR1-mediated response of detoxification genes is part of the singlet oxygen-induced acclimation process in C. reinhardtii. The sor1 mutant isolated in a screen for singlet oxygen resistant mutants and the corresponding wild-type strain 4A+ were grown in a 12 h light dark cycle for several days before total RNA was extracted 6 h after the light came on.
2012-04-03 | E-GEOD-33548 | biostudies-arrayexpress
Project description:Background: The uncontrolled and widespread use of (nano)silver compounds has led to the increased release of these compounds into the environment, raising concerns about their negative impact on ecosystems. Concomitantly, silver resistance determinants are widely spread among environmental and clinically relevant bacteria although the underlying mechanisms are not yet fully understood. Results: In this study, we show that Cupriavidus metallidurans is able to adapt to toxic silver concentrations and explicate the genetic circuit responsible for this adaptation. None of the known silver resistant determinants present in C. metallidurans are involved in the adapted response. Instead, increased silver resistance is achieved by the concerted action of a two-component system AgrR-AgrS, previously not associated with metal resistance, and two intrinsically disordered proteins PrsQ1 and PrsQ2. Both belong to an unique group of small, uncharacterized, extracellular proteins restricted to the genera Cupriavidus and Ralstonia. This system seems to be much more efficient as it gives C. metallidurans the ability to withstand much higher silver concentrations. The latter could be facilitated by the accumulation of silver ions and the formation of silver nanoparticles. Conclusions: Detailed knowledge and exploitation of this protein family could result in novel routes for metal nanoparticle formation and metal processing relevant for biotechnical and biomedical applications.
2018-12-31 | GSE107669 | GEO
Project description:Human transformer 2M-NM-2 (Tra2M-NM-2) is a serine/arginine-rich (SR)-like protein splicing factor and is now implicated to play wide-ranging roles in gene expression as an RNA-binding protein. In this study, we identified a subset of Tra2M-NM-2-associated mRNAs in HCT116 human colon cancer cells using RNA immunoprecipitation with an anti-Tra2M-NM-2 antibody and microarray analysis. Whole-cell extracts from HCT116 cells were incubated with protein-A Sepharose beads precoated with 3 M-NM-<g anti-Tra2M-NM-2 antibody or control rabbit IgG for 2 h at 4M-BM-0C. RNA in the immunoprecipitation (IP) materials was measured by human whole-genome microarray (Agilent Technology).
2014-09-03 | E-GEOD-60904 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE20859: Change in gene expression in Chlamydomonas reinhardtii upon heat shock GSE20860: Change in gene expression in Chlamydomonas reinhardtii upon feeding with hemin and Mg-protoporphyrin Refer to individual Series
2011-03-11 | E-GEOD-20861 | biostudies-arrayexpress