Project description:Cockayne syndrome is an inherited premature aging syndrome associated with developmental and neurological disorders. Mutations in the genomic locus encoding CSB are associated with 80% Cockayne syndrome cases. CSB is invovled in relieving UV-induced and oxidative stree. To gain more insights into the fucntion of CSB under these stress, we use ChIP-seq to determine the genomic localization of CSB 1 hour after UV irradiation and menadione treatment. Genomic localization of CSB and remodeling deficient CSBâN1
Project description:Cockayne syndrome is an inherited premature aging syndrome associated with developmental and neurological disorders. Mutations in the genomic locus encoding CSB are associated with 80% Cockayne syndrome cases. Transcription profiling assays reveal the association of mis-regulation of gene expression with Cockayne syndrome, highlighting the importance of CSB in transcription regulation. However, many questions remain unanswered as how CSB regulates transcription. In this study, we dissect the mechanisms by which CSB regulates transcription during normal growth. By anti-CSB chromatin immunoprecipitation followed by deep sequencing, we found CSB is enriched at genomic regions containing TGASTCA motifs, to which the immediate early gene product C-Jun binds specifically. We further demonstrate that c-Jun co-immunoprecipitates with CSB. In addition, the targeting of CSB to genomic region containing TGASTCA motifs was drastically reduced in cells treated c-Jun shRNA. Reverse transcription followed by quantitative PCR indicates that CSB can regulate gene expression nearby its binding sites, both in activation and repression. The remodeling defective CSBM-bM-^HM-^FN1 mutant is also targeted to TGASTCA motifs, but cannot always substitute CSB function in transcription regulating, suggesting the importance of remodeling by CSB in transcription regulation. Notably, the Cockayne syndrome related mutation encoding protein CSBR670W, which is defective in ATP hydrolysis but is targeted to TGASTCA motifs efficiently, indicating that ATP hydrolysis is dispensable for c-Jun mediated CSB targeting, in sharp contrast to the ATP-dependent targeting mechanism by which CSB is relocated to DNA lesion stalled transcription. Together, these results reveal a second CSB targeting mechanism in which DNA sequence specific transcription factor c-Jun targets CSB to specific genomic region and regulate gene expression. Genomic localization of CSB and remodeling deficient CSBM-bM-^HM-^FN1
Project description:Cockayne syndrome is an inherited premature aging syndrome associated with developmental and neurological disorders. Mutations in the genomic locus encoding CSB are associated with 80% Cockayne syndrome cases. CSB is invovled in relieving UV-induced and oxidative stree. To gain more insights into the fucntion of CSB under these stress, we use ChIP-seq to determine the genomic localization of CSB 1 hour after UV irradiation and menadione treatment.
Project description:Cockayne syndrome is an inherited premature aging syndrome associated with developmental and neurological disorders. Mutations in the genomic locus encoding CSB are associated with 80% Cockayne syndrome cases. Transcription profiling assays reveal the association of mis-regulation of gene expression with Cockayne syndrome, highlighting the importance of CSB in transcription regulation. However, many questions remain unanswered as how CSB regulates transcription. In this study, we dissect the mechanisms by which CSB regulates transcription during normal growth. By anti-CSB chromatin immunoprecipitation followed by deep sequencing, we found CSB is enriched at genomic regions containing TGASTCA motifs, to which the immediate early gene product C-Jun binds specifically. We further demonstrate that c-Jun co-immunoprecipitates with CSB. In addition, the targeting of CSB to genomic region containing TGASTCA motifs was drastically reduced in cells treated c-Jun shRNA. Reverse transcription followed by quantitative PCR indicates that CSB can regulate gene expression nearby its binding sites, both in activation and repression. The remodeling defective CSB∆N1 mutant is also targeted to TGASTCA motifs, but cannot always substitute CSB function in transcription regulating, suggesting the importance of remodeling by CSB in transcription regulation. Notably, the Cockayne syndrome related mutation encoding protein CSBR670W, which is defective in ATP hydrolysis but is targeted to TGASTCA motifs efficiently, indicating that ATP hydrolysis is dispensable for c-Jun mediated CSB targeting, in sharp contrast to the ATP-dependent targeting mechanism by which CSB is relocated to DNA lesion stalled transcription. Together, these results reveal a second CSB targeting mechanism in which DNA sequence specific transcription factor c-Jun targets CSB to specific genomic region and regulate gene expression.
Project description:We investigated whether transcription-coupled repair deficient mice (Cockayne syndrome B knockout mice (Csb-/-)), known to be sensitive to oxidative stressors, have a different response to ozone than its repair-proficient control, Csb heterozygote (Csb+/-) mice.
Project description:As the causative gene for cockayne syndrome, CSB has a well-characerized function in transcription-coupled nucleotide excision repair. However, the complex neurological abnormalities that affect CS patients can not be simply explained by the DNA repair defects. CSB is also involved in RNAP II transcription regulation. This study characterizes the gene expression signatures affected by CSB protein. Using Nimblegen microarray we identified differentially expressed genes in human fibroblasts derived from CS patients as compared to CSB reconstituted cell lines (wild type).
Project description:The CSB-PGBD3 fusion protein arose over 43 million years ago when a 2.5 kb piggyBac 3 (PGBD3) transposon inserted into intron 5 of the Cockayne syndrome Group B (CSB) gene in the common ancestor of all higher primates. The CSB-PGBD3 fusion protein binds internally-deleted PGBD3 elements called MER85s in vitro, and induces a strong interferon-like innate antiviral immune response when expressed in CSB-null UVSS1KO cells. To explore the connection between DNA binding and gene expression changes induced by CSB-PGBD3, we investigated the genome-wide DNA binding profile of the fusion protein. 1 ChIP sample and 1 unenriched input control from the same crosslinked chromatin pool
Project description:Cockayne syndrome (CS) is a rare genetic disorder caused by mutation of the DNA repair and chromatin remodelling proteins CSA or CSB. Increasing evidences indicate that the progeroid phenotype of CS cannot be solely ascribed to impaired DNA repair, and UV-sensitivity syndrome (UVSS) patients that are also mutated for CSA or CSB do not age prematurely. Epigenetic modifications constitute a hallmark of ageing. We assessed genome-wide DNA methylation (DNAm) at single-nucleotide resolution on fibroblasts derived from CS versus UVSS patients and healthy donors.
Project description:Cockayne syndrome (CS) is a rare genetic disorder caused by mutation of the DNA repair and chromatin remodelling proteins CSA or CSB. Increasing evidences indicate that the progeroid phenotype of CS cannot be solely ascribed to impaired DNA repair, and UV-sensitivity syndrome (UVSS) patients that are also mutated for CSA or CSB do not age prematurely. Epigenetic modifications constitute a hallmark of ageing. We assessed genome-wide DNA methylation (DNAm) at single-nucleotide resolution on fibroblasts derived from CS versus UVSS patients and healthy donors.
Project description:Cockayne syndrome is a segmental progeria most often caused by mutations in the CSB gene encoding a SWI/SNF-like ATPase required for transcription-coupled DNA repair (TCR). Over 43 Mya before marmosets diverged from humans, a piggyBac3 (PGBD3) transposable element integrated into intron 5 of the CSB gene. As a result, primate CSB genes now generate both CSB protein and a conserved CSB-PGBD3 fusion protein in which the first 5 exons of CSB are alternatively spliced to the PGBD3 transposase. We show by microarray analysis that expression of the fusion protein alone in CSB-null UV-sensitive syndrome cells (UVSS1KO) cells induces an interferon-like response that resembles both the innate antiviral response and the prolonged interferon response normally maintained by unphosphorylated STAT1 (U-STAT1); moreover, as might be expected based on conservation of the fusion protein, this potentially cytotoxic interferon-like response is largely reversed by coexpression of functional CSB protein. Interestingly, expression of CSB and the CSB-PGBD3 fusion protein together, but neither alone, upregulates the insulin growth factor binding protein IGFBP5 and downregulates IGFBP7, suggesting that the fusion protein may also confer a metabolic advantage, perhaps in the presence of DNA damage. Finally, we show that the fusion protein binds in vitro to members of a dispersed family of 900 internally deleted piggyBac elements known as MER85s, providing a potential mechanism by which the fusion protein could exert widespread effects on gene expression. Our data suggest that the CSB-PGBD3 fusion protein is important in both health and disease, and could play a role in Cockayne syndrome. 12 samples total; 4 gene expression conditions in triplicate; 1 condition is a tag-only negative control