Project description:The COP9 signalosome is a highly conserved multi-protein complex consisting of eight subunits, which influences key developmental pathways through its regulation of protein stability and transcription. In Arabidopsis thaliana, mutations in the COP9 Signalosome exhibit a number of diverse pleiotropic phenotypes. Total or partial loss of COP9 Signalosome function in Arabidopsis leads to misregulation of a number of genes involved in DNA methylation, suggesting that part of the pleiotropic phenotype is due to global effects on DNA methylation. Results: We determined and analyzed the methylomes and transcriptomes of both partial- and total-loss-of-function mutants of the COP9 Signalosome. Our results indicate that the COP9 Signalosome has a global genome-wide effect on methylation and that this effect is at least partially encoded in the DNA. In addition, our analyses suggest that COP9 Signalosome-dependent methylation is related to gene expression regulation in various ways. Differentially methylated regions tend to be closer in the 3D conformation of the genome to differentially expressed genes. These results suggest that the COP9 Signalosome has a more comprehensive effect on gene expression than thought before, and this is partially related to regulation of methylation. The high level of COP9 Signalosome conservation among eukaryotes may also suggest that COP9 Signalosome regulates methylation not only in plants but also in other eukaryotes, including humans. We report the application of Bisulfite-sequencing to compare methylation of two CSN mutants with their corresponding wild types: a non-lethal csn5a-1 mutant, vs. columbia ecotype, and a lethal, csn8 mutant, vs. Wassilewskija ecotype
Project description:The COP9 signalosome (CSN) is a highly conserved complex consisting of eight subunits, which influences key developmental pathways through its regulation of protein stability and transcription. Mutations in each of the CSN subunits exhibits diverse pleiotropic phenotypes We used microarrays to compare gene expression of two CSN mutants with their corresponding wild types: a non-lethal csn5a-1 mutant, vs. columbia ecotype, and a lethal, csn8 mutant, vs. Wassilewskija ecotype
Project description:The COP9 signalosome protein complex has a central role in the regulation of development of multi-cellular organisms. While the function of this complex in ubiquitin-mediated protein degradation is well established, results over the past few years have hinted that the COP9 signalosome may function more broadly in the regulation of gene expression. Here, using DamID technology, we show that COP9 signalosome subunit 7 functionally associates with a large number of genomic loci in the Drosophila genome, and show that the expression of many genes within these loci is COP9 signalosome-dependent. This association is likely direct as we show CSN7 binds DNA in vitro. The genes targeted by CSN7 are preferentially enriched for transcriptionally active regions of the genome, and are involved in the regulation of distinct gene ontology groupings including imaginal disc development and cell-cycle control.
Project description:The COP9 signalosome protein complex has a central role in the regulation of development of multi-cellular organisms. While the function of this complex in ubiquitin-mediated protein degradation is well established, results over the past few years have hinted that the COP9 signalosome may function more broadly in the regulation of gene expression. Here, using DamID technology, we show that COP9 signalosome subunit 7 functionally associates with a large number of genomic loci in the Drosophila genome, and show that the expression of many genes within these loci is COP9 signalosome-dependent. This association is likely direct as we show CSN7 binds DNA in vitro. The genes targeted by CSN7 are preferentially enriched for transcriptionally active regions of the genome, and are involved in the regulation of distinct gene ontology groupings including imaginal disc development and cell-cycle control. DamID experiments were done in Drosophila Kc167 cells. Samples were hybridized to 380k NimbleGen arrays with 300 bp probe spacing. The experiment contains 4 samples, three biological replicates and one reverse dye orientation. For each sample Dam-fusion material was hybridized over Dam-only material.
Project description:CSN5 has been implicated as a candidate oncogene in human breast cancers by genetic linkage with activation of the poor-prognosis, wound response gene expression signature. CSN5 is a subunit of the eight-protein COP9 signalosome, a signaling complex with multiple biochemical activities; the mechanism of CSN5 action in cancer development remains poorly understood. Here we show that CSN5 isopeptidase activity is essential for breast epithelial transformation and progression. Amplification of CSN5 is required for transformation of primary human breast epithelial cells by defined oncogenes. The transforming effects of CSN5 require CSN subunits for assembly of the full COP9 signalosome and the isopeptidase activity of CSN5, which potentiates the transcriptional activity of MYC. Transgenic inhibition of CSN5 isopeptidase activity blocks breast cancer progression evoked by MYC and RAS in vivo. These results highlight CSN5 isopeptidase activity in breast cancer progression, suggesting it as a therapeutic target in aggressive human breast cancers. A strain or line experiment design type assays differences between multiple strains, cultivars, serovars, isolates, lines from organisms of a single species. Keywords: strain_or_line_design
Project description:CSN5 has been implicated as a candidate oncogene in human breast cancers by genetic linkage with activation of the poor-prognosis, wound response gene expression signature. CSN5 is a subunit of the eight-protein COP9 signalosome, a signaling complex with multiple biochemical activities; the mechanism of CSN5 action in cancer development remains poorly understood. Here we show that CSN5 isopeptidase activity is essential for breast epithelial transformation and progression. Amplification of CSN5 is required for transformation of primary human breast epithelial cells by defined oncogenes. The transforming effects of CSN5 require CSN subunits for assembly of the full COP9 signalosome and the isopeptidase activity of CSN5, which potentiates the transcriptional activity of MYC. Transgenic inhibition of CSN5 isopeptidase activity blocks breast cancer progression evoked by MYC and RAS in vivo. These results highlight CSN5 isopeptidase activity in breast cancer progression, suggesting it as a therapeutic target in aggressive human breast cancers. This SuperSeries is composed of the SubSeries listed below.