Project description:Transcriptome analysis of two different mutants of the condensin II subunit CAP-D3. Four week-old plantlets from the T-DNA insertion lines SAIL_826_B06 (cap-d3 SAIL) and SALK_094776 (cap-d3 SALK) were compared to Col-0 wild-type plants.
Project description:BACKGROUND & AIMS- More frequent interaction of bacteria with the colonic epithelium is associated with ulcerative colitis (UC). The identities of all proteins which promote bacterial clearance in colonic epithelial cells are unknown. Previously, we discovered that dCAP-D3 (Chromosome Associated Protein-D3), regulates responses to bacterial infection. We examined whether CAP-D3 promotes bacterial clearance in human colonic epithelium. METHODS- Clearance of Salmonella or adherent-invasive Escherichia coli LF82 was assessed by gentamycin protection assays in HT-29 and Caco-2 cells expressing CAP-D3 shRNA. CAP-D3 levels in colonic epithelial cells from healthy and UC patient tissues were analyzed by immunoblot. RNA-sequencing identified bacterially-induced CAP-D3 target genes. The role of CAP-D3 target genes in bacterial clearance was analyzed by gentamycin protection assays, immunofluorescent staining, and by using pharmacologic inhibitors. RESULTS- CAP-D3 expression was reduced in colonic epithelial cells from UC patients with active disease. Reduction of CAP-D3 expression inhibited autophagy and decreased intracellular bacterial clearance. The components of the heterodimeric SLC7A5/SLC3A2 amino acid transporter were identified as CAP-D3 target genes; their levels increased in infected, CAP-D3 deficient cell lines and in cells from UC patients. In HT-29 cells, this resulted in earlier SLC7A5 recruitment to Salmonella-containing vacuoles, increased mTOR activity, and enhanced bacterial survival. Inhibition of SLC7A5/SLC3A2 or mTOR activity rescued the bacterial clearance defect in CAP-D3 deficient cells. CONCLUSIONS- CAP-D3 attenuates amino acid transporter transcription to promote bacterial autophagy in colon epithelial cells. CAP-D3 protein levels are decreased in patients with active UC, suggesting that CAP-D3 is a potential therapeutic target to restore mucosal homeostasis in UC patients.
Project description:BACKGROUND & AIMS- More frequent interaction of bacteria with the colonic epithelium is associated with ulcerative colitis (UC). The identities of all proteins which promote bacterial clearance in colonic epithelial cells are unknown. Previously, we discovered that dCAP-D3 (Chromosome Associated Protein-D3), regulates responses to bacterial infection. We examined whether CAP-D3 promotes bacterial clearance in human colonic epithelium. METHODS- Clearance of Salmonella or adherent-invasive Escherichia coli LF82 was assessed by gentamycin protection assays in HT-29 and Caco-2 cells expressing CAP-D3 shRNA. CAP-D3 levels in colonic epithelial cells from healthy and UC patient tissues were analyzed by immunoblot. RNA-sequencing identified bacterially-induced CAP-D3 target genes. The role of CAP-D3 target genes in bacterial clearance was analyzed by gentamycin protection assays, immunofluorescent staining, and by using pharmacologic inhibitors. RESULTS- CAP-D3 expression was reduced in colonic epithelial cells from UC patients with active disease. Reduction of CAP-D3 expression inhibited autophagy and decreased intracellular bacterial clearance. The components of the heterodimeric SLC7A5/SLC3A2 amino acid transporter were identified as CAP-D3 target genes; their levels increased in infected, CAP-D3 deficient cell lines and in cells from UC patients. In HT-29 cells, this resulted in earlier SLC7A5 recruitment to Salmonella-containing vacuoles, increased mTOR activity, and enhanced bacterial survival. Inhibition of SLC7A5/SLC3A2 or mTOR activity rescued the bacterial clearance defect in CAP-D3 deficient cells. CONCLUSIONS- CAP-D3 attenuates amino acid transporter transcription to promote bacterial autophagy in colon epithelial cells. CAP-D3 protein levels are decreased in patients with active UC, suggesting that CAP-D3 is a potential therapeutic target to restore mucosal homeostasis in UC patients. Three RNA samples from 3 independent experiments including timepoints taken at 0, 0.5 and 7 hours post-infection were analyzed on a bioanalyzer for quality; one of the 0.5 hour post-infection samples was excluded at this time due to poor RNA purity. Directional, cDNA libraries made from cellular mRNAs were generated from the other 8 samples and sequenced (paired-end sequencing of 100 bp reads) in the Genomics Core at the University of Chicago on an Illumina HiSeq2000.
Project description:The goal of this experiment was to identify transcripts that are differentially expressed in CAP-D3 and CAP-H2 depleted cells with and without exposure to menadione
Project description:Genome instability is a characteristic of malignant cells, however, evidence for its contribution to tumorigenesis has been enigmatic. In this study we demonstrate that a complex containing the retinoblastoma protein, E2F1, and Condensin II localizes to major satellite repeats at pericentromeres. In the absence of this complex, this genomic region fails to properly replicate and H2AX phosphorylation at pericentromeric repeats is increased. Our data indicates that these lesions contribute to defective chromosome segregation in the ensuing mitosis. Surprisingly, loss of even one copy of the retinoblastoma gene was sufficient to reduce recruitment of Condensin II to pericentromeres and cause this phenotype. Furthermore, we determined that human RB1 mutation status in cancers of mesenchymal origin correlated with copy number variation, chromosomal gains and losses, as well as chromothriptic rearrangements. Importantly, the magnitude of these chromosomal abnormalities was indistinguishable between RB1+/- and RB1-/- genotypes. Lastly, using gene-targeted mice we determined that mutation of just one copy of the murine Rb1 gene causes sarcomas and lymphomas with increased chromosome copy number variation. Our study connects replication stress with a number of common chromosomal abnormalities in cancer through a dosage sensitive complex present at pericentromeric repeats. CAP-D3 localization was studied in two different genotypes: Rb+/+ and RbΔL/ΔL. As a control, input from the ChIP experiment was also sequenced. The CAP-D3 antibody used was raised against a GST fusion protein containing amino acids 1243-1506 (Coschi et al., 2010).
Project description:As the most common mRNA cap, the m7G cap impacts the fate of an mRNA in eukaryotes. The metabolite and redox agent, nicotinamide adenine diphosphate (NAD+), can be used as an initiating nucleotide in RNA synthesis to result in NAD+-capped RNAs. Such RNAs have been identified in bacteria, yeast, and human cells, but it is not known whether they exist in plant transcriptomes. The functions of the NAD+ cap in RNA metabolism or translation are still poorly understood. Here, through NAD captureSeq, we show that NAD+- capped RNAs are widespread in Arabidopsis thaliana. NAD+-capped RNAs are predominantly messenger RNAs encoded by the nuclear and mitochondrial genomes but not the chloroplast genome. NAD-capped transcripts from the nuclear genome appear to be spliced and polyadenylated. Furthermore, although NAD+-capped transcripts constitute a small proportion of the total transcript pool from any gene, they are enriched in the polysomal fraction and associate with translating ribosomes. Our findings implicate the existence of as yet unknown mechanisms of translation initiation on NAD+-capped mRNAs. More importantly, our findings suggest that cellular metabolic and/or redox states may influence, and maybe regulated by, mRNA NAD capping.
Project description:mRNA cap addition occurs early during RNA pol II transcription, facilitating pre-mRNA processing and translation. We report that the mammalian mRNA cap methyltransferase, RNMT-RAM, promotes RNA pol II transcription, independently of mRNA capping and translation. In cells, sub-lethal suppression of RNMT-RAM reduces RNA pol II occupancy, net mRNA synthesis and pre-mRNA levels. Conversely, expression of RNMT-RAM increases transcription independently of cap methyltransferase activity. In isolated nuclei, recombinant RNMT-RAM stimulates transcriptional output; this requires the RAM RNA-binding domain. RNMT-RAM interacts with nascent transcripts along their entire length and with transcription associated factors including RNA pol II subunits, SPT4, SPT6 and PAFc. Suppression of RNMT-RAM inhibits transcriptional markers including histone H2B K120 ubiquitination, H3 K4 and K36 methylation, RNA pol II S5 and S2 phosphorylation and PAFc recruitment. These findings suggest that multiple interactions between RNMT-RAM, RNA pol II factors and RNA along the transcription unit stimulate transcription.
Project description:An experiment was performed to compare global transcription patterns in two tissues of Lepidium sativum seeds at different times during imbibition leading up to, but not including, radicle protrusion from the seed (e.g. germination). RNA extractions from the two tissues were hybridised to CATMA Arabidopsis microarrays. The two tissues were the radicle and the micropylar endosperm cap that covers it. The interaction of these two tissues is thought to control the timing of germination though alterations in the extensibility of the radicle and the physical resistance of the micropylar endosperm cap to radicle penetration.