The Atss3 mutant and WT plants were arranged according to a Randomized Complete Block Design. The plants were planted in rows with seven rows in each flat; two plants of the same genotype/pot. Plants were grown under a SD photoperiod (8 h light/16 h dark) in a growth chamber as described. Eight randomly selected rows were harvested for each time point from different flats. Plant material was harvested at five time points in the diurnal cycle (1, 4, 8.5, 12, and 16 h; Time 0 is the beginning of the light period); harvesting was conducted under a green safety light. Each sample consisted of rosette leaves (leaves 5 to 8, staged following Bowmann (1994); photosynthetically active (Stessman et al., 2002)) from sixteen six-week-old plants. Leaf samples were frozen in liquid N2 immediately after harvest and stored at -80C for RNA extraction. The experiment was done twice and independent randomizations for plant growth and harvest were used for the two replicates.
Identification of the novel protein QQS as a component of the starch metabolic network in Arabidopsis leaves.
No sample metadata fields
View SamplesOncogene-induced DNA methylation-mediated transcriptional silencing of tumor suppressors frequently occurs in cancer, but the mechanism and functional role of this silencing in oncogenesis is not fully understood. Here, we show that oncogenic epidermal growth factor receptor (EGFR) induces silencing of multiple unrelated tumor suppressors in lung adenocarcinomas and glioblastomas by inhibiting DNA demethylase TET oncogene family member 1 (TET1) via the C/EBP transcription factor. After oncogenic EGFR inhibition, TET1 binds to tumor suppressor promoters and induces their re-expression via active DNA demethylation. Ectopic expression of TET1 potently inhibits lung and glioblastoma tumor growth, and TET1 knockdown confers resistance to EGFR inhibitors in lung cancer cells. Lung cancer samples exhibited reduced TET1 expression or TET1 cytoplasmic localization in a majority of cases. Collectively, these results identify a conserved pathway of oncogenic EGFR-induced DNA methylation-mediated transcriptional silencing of tumor suppressors, which may have therapeutic benefit for oncogenic EGFR-mediated lung cancers and glioblastomas.
Oncogenic EGFR Represses the TET1 DNA Demethylase to Induce Silencing of Tumor Suppressors in Cancer Cells.
Cell line
View SamplesIn a transgenic mouse model of Alzheimer disease (AD), cleavage of the amyloid precursor protein (APP) by the -secretase ADAM10 prevented amyloid plaque formation and alleviated cognitive deficits. Furthermore, there was a positive influence of ADAM10 over-expression on neurotransmitter-specific formation of synapses and on synaptic plasticity.
Differential gene expression in ADAM10 and mutant ADAM10 transgenic mice.
Sex, Age
View SamplesWe use mice containing a gene trap in the first intron of the Rest gene, which effectively eliminates transcription from all coding exons, to prematurely remove REST from neural progenitors. We find catastrophic DNA damage that occurs during S-phase of the cell cycle and concominant with activation of p53 pro-apoptotic sgnalling, with consequences including abnormal chromosome separation, apoptosis, and smaller brains.
The REST remodeling complex protects genomic integrity during embryonic neurogenesis.
Specimen part
View SamplesWe use mice containing a gene trap in the first intron of the Rest gene, which effectively eliminates transcription from all coding exons, to prematurely remove REST from neural progenitors. We find catastrophic DNA damage that occurs during S-phase of the cell cycle, with consequences including abnormal chromosome separation, apoptosis, and smaller brains. Further support for persistent effects is the latent appearance of proneural glioblastomas in adult mice also lacking the tumor suppressor, p53. A Rest deficient mouse line generated previously, using a conventional gene targeting approach, does not exhibit these phenotypes, likely due to a remaining C terminal peptide that still binds chromatin and recruits REST chromatin modifiers.Our results indicate that REST-mediated chromatin remodeling is required for proper S-phase dynamics, prior to its well-established role in relieving repression of neuronal genes at terminal differentiation.
The REST remodeling complex protects genomic integrity during embryonic neurogenesis.
Specimen part
View SamplesUpstream of N-ras (UNR) is a conserved RNA-binding protein that regulates mRNA translation and stability by binding to sites generally located in untranslated regions (UTRs). In Drosophila, sex-specific binding of UNR to msl2 mRNA and the non-coding RNA roX plays key roles in the control of X-chromosome dosage compensation in both sexes. In order to investigate broader sex-specific functions of UNR, we have identified its RNA targets in adult male and female flies by high-throughput RNA binding and transcriptome analysis. Here we show that UNR binds to a large set of protein-coding transcripts and to a smaller set of non-coding RNAs in a sex-specific fashion. Overall design: Two replicates of UNR IP were performed in D.melanogaster adult males and females, and enrichment in either sex was compared with IgG IP as control. To correlate sex-specific UNR binding with sex-specific transcription and splicing we performed RNA-Seq experiments in males and females.
Widespread generation of alternative UTRs contributes to sex-specific RNA binding by UNR.
Specimen part, Subject
View SamplesMammalian mRNAs are generated by complex and coordinated biogenesis pathways and acquire 5'-end m7G caps that play fundamental roles in processing and translation. Here we show that several selenoprotein mRNAs are not recognized efficiently by translation initiation factor eIF4E because they bear a hypermethylated cap. This cap modification is acquired via a 5end maturation pathway similar to that of the small nucle(ol)ar RNAs (sn- and snoRNAs). Our findings also establish that the trimethylguanosine synthase 1 (Tgs1) interacts with selenoprotein mRNAs for cap hypermethylation and that assembly chaperones and core proteins devoted to sn- and snoRNP maturation contribute to recruiting Tgs1 to selenoprotein mRNPs. We further demonstrate that the hypermethylated-capped selenoprotein mRNAs localize to the cytoplasm, are associated with polysomes and thus translated. Moreover, we found that the activity of Tgs1, but not of eIF4E, is required for the synthesis of the GPx1 selenoprotein in vivo.
Hypermethylated-capped selenoprotein mRNAs in mammals.
Cell line
View SamplesCHD5 is frequently deleted in neuroblastoma, and appears to be a tumor suppressor gene; however, little is known about the role of CHD5. We found CHD5 mRNA was restricted to brain; by contrast most other remodeling ATPases were broadly expressed. CHD5 protein isolated from mouse brain was associated with HDAC2, p66, MTA3 and RbAp46 in a megadalton complex. CHD5 protein was detected in several rat brain regions and appeared to be enriched in neurons. CHD5 protein was predominantly nuclear in primary rat neurons and brain sections. Microarray analysis revealed genes that were upregulated and downregulated when CHD5 was depleted from primary neurons. CHD5 depletion altered expression of neuronal genes, transcription factors, and brain-specific subunits of the SWI/SNF remodeling enzyme. Aging and Alzheimers gene sets were strongly affected by CHD5 depletion from primary neurons. Chromatin immunoprecipitation revealed CHD5 bound to these genes, suggesting the regulation was direct. Together, these results indicate that CHD5 is found in a NuRD-like multi-protein complex. CHD5 is restricted to the brain, unlike the closely related family members CHD3 and CHD4. CHD5 regulates expression of neuronal genes, cell cycle genes and remodeling genes. CHD5 is linked to regulation of aging and Alzheimers genes.
CHD5, a brain-specific paralog of Mi2 chromatin remodeling enzymes, regulates expression of neuronal genes.
Specimen part
View Samples3 pairs of wt and ClC-6 knockout mice, RNA from p14 hippocampus
Lysosomal storage disease upon disruption of the neuronal chloride transport protein ClC-6.
Sex, Age, Specimen part, Subject, Time
View SamplesWe used microarrays to detail the global programme of gene expression underlying cardiac development by HDAC2 and identified distinct classes of up-regulated and down-regulated genes during this process.
Hdac2 regulates the cardiac hypertrophic response by modulating Gsk3 beta activity.
No sample metadata fields
View Samples