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SRP172777
Arabidopsis thaliana
6 Downloadable Samples
Illumina HiSeq 4000
Description
The polycomb repressive complex 2 (PRC2) regulates epigenetic gene repression in eukaryotes. Mechanisms controlling its developmental specificity and signal-responsiveness are poorly understood. Here, we identify an oxygen-sensitive N-terminal (N-) degron in the plant PRC2 subunit VERNALIZATION(VRN)2, a homolog of animal Su(z)12, that promotes its degradation via the N-end rule pathway. We provide evidence that this N-degron arose early during angiosperm evolution via gene duplication and N-terminal truncation, facilitating expansion of PRC2 function in flowering plants. We show that proteolysis via the N-end rule pathway prevents ectopic VRN2 accumulation, and that hypoxia and long-term cold exposure lead to increased VRN2 abundance, which we propose may be due to inhibition of VRN2 turnover via its N-degron. Furthermore, we identify an overlap in the transcriptional responses to hypoxia and prolonged cold, and show that VRN2 promotes tolerance to hypoxia. Our work reveals a mechanism for post-translational regulation of VRN2 stability that could potentially link environmental inputs to the epigenetic control of plant development. Overall design: RNA was extracted from non-vernalized (0v; C) or 4 week vernalized (4v; V) seedlings. Three biological replicates for each treatment were used for subsequent RNA sequencing
Publication Title
Oxygen-dependent proteolysis regulates the stability of angiosperm polycomb repressive complex 2 subunit VERNALIZATION 2.
Sample Metadata Fields
Specimen part, Treatment, Subject
View Samples- Homo sapiens
- 24 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Resistance to tamoxifen in breast cancer patients is a serious therapeutic problem and major efforts are underway to understand underlying mechanisms. Resistance can be either intrinsic or acquired. We derived a series of subcloned MCF7 cell lines that were either highly sensitive or naturally resistant to tamoxifen and studied the factors that lead to drug resistance. Gene-expression studies revealed a signature of 67 genes that differentially respond to tamoxifen in sensitive vs. resistant subclones, which also predicts disease-free survival in tamoxifen-treated patients. High-throughput cell-based screens, in which >500 human kinases were independently ectopically expressed, identified 31 kinases that conferred drug resistance on sensitive cells. One of these, HSPB8, was also in the expression signature and, by itself, predicted poor clinical outcome in one cohort of patients. Further studies revealed that HSPB8 protected MCF7 cells from tamoxifen and blocked autophagy. Moreover, silencing HSBP8 induced autophagy and caused cell death. Tamoxifen itself induced autophagy in sensitive cells but not in resistant ones, and tamoxifen-resistant cells were sensitive to the induction of autophagy by other drugs. These results may point to an important role for autophagy in the sensitivity to tamoxifen.
Publication Title
High-throughput ectopic expression screen for tamoxifen resistance identifies an atypical kinase that blocks autophagy.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Pseudomonas aeruginosa
- 8 Downloadable Samples
- Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
The response of bacteria to the conditions at the site of infection is a key part of the transcriptional program that will determine the sucess of the infectious agent. To model the environment of the distal airway, we used bovine pulmonary surfactant (Survanta). P. aeruginosa transcript levels were measured in the presence or absence of Survanta in MOPS minimal medium to identify transcripts altered in response to surfactant. The most highly induced transcript in Survanta was PA5325, renamed sphA based on our findings that the gene was specifically induced by sphingosine derived from the sphingomyelin present in pulmonary surfactant. A divergently transcribed transcription factor, PA5324, was demonstrated to be critical for the sphingosine dependent induction of sphA and was therefore renamed SphR. Microarrays of the sphR mutant cells were compared to wild type to determine the likely SphR regulon.
Publication Title
Detection of host-derived sphingosine by Pseudomonas aeruginosa is important for survival in the murine lung.
Sample Metadata Fields
Treatment
View Samples- Homo sapiens
- 3 Downloadable Samples
- IlluminaHiSeq2000
Description
Despite 20 years since its discovery, the gene responsible for Huntington’s Disease, HTT, has still not had its function or transcriptional profile completely characterized. In response to a recent report by Ruzo et al. of several novel splice forms of HTT in human embryonic stem cell lines, we have analyzed a set of mRNA sequencing datasets from post mortem human brain from Huntington’s disease, Parkinson’s disease, and neurologically normal control subjects to evaluate support for previously observed and to identify novel splice patterns. A custom analysis pipeline produced supporting evidence for some of the results reported by two previous studies of alternative isoforms as well as identifying previously unreported splice patterns. All of the alternative splice patterns were of relatively low abundance compared to the canonical splice form. Overall design: 29 Huntington''s Disease, 29 Parkinson''s Disease, and 50 Neurologically normal control samples from human post-mortem prefrontal cortex
Publication Title
Evidence of Extensive Alternative Splicing in Post Mortem Human Brain HTT Transcription by mRNA Sequencing.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 38 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
STAT1 is overexpressed in tumors selected for radioresistance and confers protection from radiation in transduced sensitive cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 18 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Nu61, a radiation-resistant human tumor xenograft, was selected from a parental radiosensitive tumor SCC-61 by eight serial cycles of passage in athymic nude mice and in vivo irradiation.
Publication Title
STAT1 is overexpressed in tumors selected for radioresistance and confers protection from radiation in transduced sensitive cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Pseudomonas aeruginosa
- 12 Downloadable Samples
- Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
Pseudomonas aeruginosa displays tremendous metabolic diversity, controlled in part by the abundance of transcription regulators in the genome. We have been investigating P. aeruginosas response to the host, particularly changes regulated by the host-derived quaternary amines choline and glycine betaine (GB). We previously identified GbdR as an AraC-family transcription factor that directly regulates choline acquisition from host phospholipids (via binding to plcH and pchP promoters), is required for catabolism of the choline metabolite GB, and is an activator that induces transcription in response to GB or dimethylglycine. Our goal was to characterize the GbdR regulon in P. aeruginosa using genetics and chemical biology in combination with transcriptomics and in vitro DNA-binding assays. Here we show that GbdR activation regulates transcription of 26 genes from 12 promoters; 11 of which have measureable binding to GbdR in vitro. The GbdR regulon includes the genes encoding GB, dimethylglycine, sarcosine, glycine, and serine catabolic enzymes, and the BetX and CbcXWV quaternary amine transport proteins. . Additionally, identification of two uncharacterized regulon members suggests roles for these proteins in response to choline metabolites.
Publication Title
Characterization of the GbdR regulon in Pseudomonas aeruginosa.
Sample Metadata Fields
Treatment
View Samples- Homo sapiens
- 12 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Nu61, a radiation-resistant human tumor xenograft, was selected from a parental radiosensitive tumor SCC-61 by eight serial cycles of passage in athymic nude mice and in vivo irradiation.
Publication Title
STAT1 is overexpressed in tumors selected for radioresistance and confers protection from radiation in transduced sensitive cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Nu61, a radiation-resistant human tumor xenograft, was selected from a parental radiosensitive tumor SCC-61 by eight serial cycles of passage in athymic nude mice and in vivo irradiation.
Publication Title
STAT1 is overexpressed in tumors selected for radioresistance and confers protection from radiation in transduced sensitive cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Saccharomyces cerevisiae
- 23 Downloadable Samples
- Affymetrix Yeast Genome 2.0 Array (yeast2)
Description
We used microarrays to detail the global program of gene expression underlying rRNA processing gene regulation during heat shock. PBF1 is YBL054W (TOD6) and PBF2 is YER088C (DOT6).
Publication Title
High-resolution DNA-binding specificity analysis of yeast transcription factors.
Sample Metadata Fields
No sample metadata fields
View Samples