Cdc34 is an essential E2 ubiquitin conjugating enzyme found in nearly all eukaryotes. It contains a highly conserved motif composed of S73/S97/12 amino acid insert near the active site cysteine. This motif is unique to Cdc34/Ubc7 type E2s while other E2s contain K/D/no insert at these positions. To better understand the function of this motif we mutated Cdc34 S73/S97/insert to be K/D/no insert and observed changes in transcript levels in mid-log phase yeast cells. ABSTRACT [Cdc34 is a ubiquitin conjugating enzyme necessary for the ubiquitylation of substrates by the SCF family of ubiquitin ligases. Previous work has shown that the Cdc34 protein is phosphorylated in vivo on serine residues. Cdc34 contains two serines within its catalytic domain, S73 and S97, that together with a 12 amino acid acidic loop, constitute a highly conserved motif (serine, serine, insert) among all members of the Cdc34 family of E2 enzymes. Using phosphospecific antibodies, we show that the essential serine S97 is indeed phosphorylated in vivo. Furthermore, this phosphorylation event is regulated by treatment with pheromone in yeast. Consistently, expression of a Cdc34 mutant lacking this motif (serine, serine, insert) leads to misregulation of the SCF substrates, Sic1, Far1, Cln1 and Cln2 and suppresses the cell cycle arrest brought about by an activated mating pathway. We further explored the function of this motif by microarray analysis and show that the transcripts of nearly the entire Sic1 cluster of co-transcribed genes is altered in a strain the expresses Cdc34 lacking this motif. Our data reveals that this highly conserved motif in Cdc34 and its phosphorylation are important for modulating SCF substrate abundance both transcriptionally and post-transcriptionally.]
New insight into the role of the Cdc34 ubiquitin-conjugating enzyme in cell cycle regulation via Ace2 and Sic1.
No sample metadata fields
View SamplesThe onset and progression of breast cancer are linked to genetic and epigenetic changes that alter the normal programming of cells. Epigenetic modifications of DNA and histones contribute to chromatin structure that results in the activation or repression of gene expression. Several epigenetic pathways have been shown to be highly deregulated in cancer cells. Targeting specific histone modifications represents a viable strategy to prevent oncogenic transformation, tumor growth or metastasis. Methylation of histone H3 lysine 4 has been extensively studied and shown to mark genes for expression; however this residue can also be acetylated and the specific function of this alteration is less well known. To define the relative roles of histone H3 methylation (H3K4me3) and acetylation (H3K4ac) in breast cancer, we determined genomic regions enriched for both marks in normal-like (MCF10A), transformed (MCF7) and metastatic (MDA-MB-231) cells using a genome-wide ChIP-Seq approach. Our data revealed a genome-wide gain of H3K4ac associated with both early and late breast cancer cell phenotypes, while gain of H3K4me3 was predominantly associated with late stage cancer cells. Enrichment of H3K4ac was overrepresented at promoters of genes associated with cancer-related phenotypic traits, such as estrogen response and epithelial-to-mesenchymal transition pathways. Our findings highlight an important role for H3K4ac in predicting epigenetic changes associated with early stages of transformation. In addition, our data provide a valuable resource for understanding epigenetic signatures that correlate with known breast cancer-associated oncogenic pathways. Overall design: RNA-Seq of cell lines MCF10A, MCF7 and MDA-MB-231.
Histone H3 lysine 4 acetylation and methylation dynamics define breast cancer subtypes.
No sample metadata fields
View SamplesTORC1 is a structurally and functionally conserved multiprotein complex that regulates many aspects of eukaryote growth including the synthesis and assembly of ribosomes. The protein kinase activity of this complex is responsive to environmental cues and is potently inhibited by the natural product macrolide rapamycin. Insights into how TORC1 regulates growth have been provided with the recent identification of the rapamycin-sensitive phosphoproteome in yeast. Building on these data, we show here that Sch9, an AGC family kinase and direct substrate of TORC1, promotes ribosome biogenesis (ribi) and ribosomal protein (RP) gene expression via direct inhibitory phosphorylation of three transcription repressors, Stb3, Dot6 and Tod6. Dephosphorylation of these factors allows them to recruit the RPD3L histone deactelyase complex to ribi/RP gene promoters. Since rRNA and tRNA transcription are also under its control, Sch9 appears to be well positioned to coordinately regulate transcriptional aspects of ribosome biogenesis. Overall design: mRNA-Seq of 8 S. cerevisiae strains treated with either DMSO alone or 1NM-PP1, a small molecule inhibitor for analog-sensitive kinases such as sch9-as.
Sch9 regulates ribosome biogenesis via Stb3, Dot6 and Tod6 and the histone deacetylase complex RPD3L.
Specimen part, Cell line, Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Comparing Platforms for Messenger RNA Expression Profiling of Archival Formalin-Fixed, Paraffin-Embedded Tissues.
Specimen part, Disease
View SamplesTo study feasibility of gene expression profiling from FFPE tissues using NuGen amplified mRNA hybridized on Affymetrix GeneChip Human Gene 1.0 ST arrays, we designed a pilot study utilizing samples from prostate cancer cohort. We selected samples from large-scale epidemiologic studies and clinical trials representative of a wide variety of fixation times, block ages and block storage conditions.
Comparing Platforms for Messenger RNA Expression Profiling of Archival Formalin-Fixed, Paraffin-Embedded Tissues.
Specimen part
View SamplesTo study feasibility of gene expression profiling from FFPE tissues using NuGen amplified mRNA hybridized on Affymetrix GeneChip Human Gene 1.0 ST arrays, we designed a pilot study utilizing samples from prostate cancer cohort. We selected samples from large-scale epidemiologic studies and clinical trials representative of a wide variety of fixation times, block ages and block storage conditions.
Comparing Platforms for Messenger RNA Expression Profiling of Archival Formalin-Fixed, Paraffin-Embedded Tissues.
Disease
View Samples26972c yeast cells were transformed with either empty vector (pYES3) or pYES3:Gm:bHLHm1. Cells were grown on low ammonium concentrations to observe transcriptional changes in the yeast genome in response to the soybean bHLHm1 transcription factor.
Soybean SAT1 (Symbiotic Ammonium Transporter 1) encodes a bHLH transcription factor involved in nodule growth and NH4+ transport.
No sample metadata fields
View SamplesThese RNA-seq data were generated to correlate with genomic interaction data in a related Hi-C analysis. MCF10A is a normal-like mammary epithelial cell line and MCF7 is a transformed estrogen responsive breast cancer cell line derived from a metastatic site; both are commonly used in models of breast cancer progression. Analysis revealed a set of genes related to repression of WNT signalling that were both up-regulated in MCF7 and located in genomic regions that had transitioned from closed to open structure in MCF7. Overall design: RNA-seq of MCF10A and MCF7 cells. 3 replicates each. Sequencing was strand-specific and conducted on ribo-depleted RNA.
Chromatin interaction analysis reveals changes in small chromosome and telomere clustering between epithelial and breast cancer cells.
No sample metadata fields
View SamplesAs part of a larger study on Cell-specific vacuolar calcium compartmentation regulates apoplastic calcium concentration, gas exchange and plant productivity we compared the transcriptome of 40day old CAX1/CAX3 double mutants to Col-0 wildtype plants.
Cell-specific vacuolar calcium storage mediated by CAX1 regulates apoplastic calcium concentration, gas exchange, and plant productivity in Arabidopsis.
Age, Specimen part
View SamplesGlioblastomas grow in a rich neurochemical mileu, but targeting neurochemical signaling as a potential therapeutic avenue for these incurable tumors has been underexplored. Thus, we probed patient derived glioblastoma stem cells with a focused library of neurochemicals, to identify new therapeutic targets. Dopaminergic, serotonergic and cholinergic pathways were found to be active against glioblastoma. In particular, dopamine receptor D4 (DRD4) antagonists selectively inhibited glioblastoma growth in vitro and in vivo, in addition to showing synergistic effect with temozolomide. Small molecule or genetic antagonism of DRD4 suppressed ERK1/2 signaling and impaired autophagic flux causing accumulation of autophagic vacuoles and ubiquitinated proteins, associated with G0/G1 cell cycle arrest. These data suggest a new mechanism for treating glioblastoma through modulating dopamine DRD4 signaling.
Inhibition of Dopamine Receptor D4 Impedes Autophagic Flux, Proliferation, and Survival of Glioblastoma Stem Cells.
Specimen part
View Samples