Genome-wide analysis of p53 transcriptional programs in B cells upon exposure to genotoxic stress in vivo [RNA-Seq]
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ABSTRACT: The tumor suppressor p53 is a transcription factor that coordinates the cellular response to DNA damage. Here we provide an integrated analysis of p53 genomic occupancy and p53-dependent gene regulation in the splenic B and non-B cell compartments of mice exposed to whole-body ionizing radiation, providing insight into general principles of p53 activity in vivo. In unstressed conditions, p53 bound few genomic targets; induction of p53 by ionizing radiation increased the number of p53 bound sites, leading to highly overlapping profiles in the different cell types. Comparison of these profiles with chromatin features in unstressed B cells revealed that, upon activation, p53 localized at active promoters, distal enhancers, and a smaller set of unmarked distal regions. At promoters, recognition of the canonical p53 motif as well as binding strength were associated with p53-dependent transcriptional activation, but not repression, indicating that the latter was most likely indirect. p53-activated targets constituted the core of a cell type-independent response, superimposed onto a cell type-specific program. Core response genes included most of the known p53-regulated genes, as well as many new ones. Our data represent a unique characterization of the p53-regulated response to ionizing radiation in vivo. Total RNA profiling of gene expression in the splenic B and non-B cell compartments of wild-type and Trp53-/-mice exposed to whole-body ionizing radiation by Illumina sequencing
Project description:The tumor suppressor p53 is a transcription factor that coordinates the cellular response to DNA damage. Here we provide an integrated analysis of p53 genomic occupancy and p53-dependent gene regulation in the splenic B and non-B cell compartments of mice exposed to whole-body ionizing radiation, providing insight into general principles of p53 activity in vivo. In unstressed conditions, p53 bound few genomic targets; induction of p53 by ionizing radiation increased the number of p53 bound sites, leading to highly overlapping profiles in the different cell types. Comparison of these profiles with chromatin features in unstressed B cells revealed that, upon activation, p53 localized at active promoters, distal enhancers, and a smaller set of unmarked distal regions. At promoters, recognition of the canonical p53 motif as well as binding strength were associated with p53-dependent transcriptional activation, but not repression, indicating that the latter was most likely indirect. p53-activated targets constituted the core of a cell type-independent response, superimposed onto a cell type-specific program. Core response genes included most of the known p53-regulated genes, as well as many new ones. Our data represent a unique characterization of the p53-regulated response to ionizing radiation in vivo. Mapping p53 binding sites in the splenic B and non-B cell compartments of mice exposed to whole-body ionizing radiation
Project description:The tumor suppressor p53 is a transcription factor that coordinates the cellular response to DNA damage. Here we provide an integrated analysis of p53 genomic occupancy and p53-dependent gene regulation in the splenic B and non-B cell compartments of mice exposed to whole-body ionizing radiation, providing insight into general principles of p53 activity in vivo. In unstressed conditions, p53 bound few genomic targets; induction of p53 by ionizing radiation increased the number of p53 bound sites, leading to highly overlapping profiles in the different cell types. Comparison of these profiles with chromatin features in unstressed B cells revealed that, upon activation, p53 localized at active promoters, distal enhancers, and a smaller set of unmarked distal regions. At promoters, recognition of the canonical p53 motif as well as binding strength were associated with p53-dependent transcriptional activation, but not repression, indicating that the latter was most likely indirect. p53-activated targets constituted the core of a cell type-independent response, superimposed onto a cell type-specific program. Core response genes included most of the known p53-regulated genes, as well as many new ones. Our data represent a unique characterization of the p53-regulated response to ionizing radiation in vivo. Mapping accessible chromatin regions in splenic B cells
Project description:The tumor suppressor p53 is a transcription factor that coordinates the cellular response to DNA damage. Here we provide an integrated analysis of p53 genomic occupancy and p53-dependent gene regulation in the splenic B and non-B cell compartments of mice exposed to whole-body ionizing radiation, providing insight into general principles of p53 activity in vivo. In unstressed conditions, p53 bound few genomic targets; induction of p53 by ionizing radiation increased the number of p53 bound sites, leading to highly overlapping profiles in the different cell types. Comparison of these profiles with chromatin features in unstressed B cells revealed that, upon activation, p53 localized at active promoters, distal enhancers, and a smaller set of unmarked distal regions. At promoters, recognition of the canonical p53 motif as well as binding strength were associated with p53-dependent transcriptional activation, but not repression, indicating that the latter was most likely indirect. p53-activated targets constituted the core of a cell type-independent response, superimposed onto a cell type-specific program. Core response genes included most of the known p53-regulated genes, as well as many new ones. Our data represent a unique characterization of the p53-regulated response to ionizing radiation in vivo.
Project description:The tumor suppressor p53 is a transcription factor that coordinates the cellular response to DNA damage. Here we provide an integrated analysis of p53 genomic occupancy and p53-dependent gene regulation in the splenic B and non-B cell compartments of mice exposed to whole-body ionizing radiation, providing insight into general principles of p53 activity in vivo. In unstressed conditions, p53 bound few genomic targets; induction of p53 by ionizing radiation increased the number of p53 bound sites, leading to highly overlapping profiles in the different cell types. Comparison of these profiles with chromatin features in unstressed B cells revealed that, upon activation, p53 localized at active promoters, distal enhancers, and a smaller set of unmarked distal regions. At promoters, recognition of the canonical p53 motif as well as binding strength were associated with p53-dependent transcriptional activation, but not repression, indicating that the latter was most likely indirect. p53-activated targets constituted the core of a cell type-independent response, superimposed onto a cell type-specific program. Core response genes included most of the known p53-regulated genes, as well as many new ones. Our data represent a unique characterization of the p53-regulated response to ionizing radiation in vivo.
Project description:The tumor suppressor p53 is a transcription factor that coordinates the cellular response to DNA damage. Here we provide an integrated analysis of p53 genomic occupancy and p53-dependent gene regulation in the splenic B and non-B cell compartments of mice exposed to whole-body ionizing radiation, providing insight into general principles of p53 activity in vivo. In unstressed conditions, p53 bound few genomic targets; induction of p53 by ionizing radiation increased the number of p53 bound sites, leading to highly overlapping profiles in the different cell types. Comparison of these profiles with chromatin features in unstressed B cells revealed that, upon activation, p53 localized at active promoters, distal enhancers, and a smaller set of unmarked distal regions. At promoters, recognition of the canonical p53 motif as well as binding strength were associated with p53-dependent transcriptional activation, but not repression, indicating that the latter was most likely indirect. p53-activated targets constituted the core of a cell type-independent response, superimposed onto a cell type-specific program. Core response genes included most of the known p53-regulated genes, as well as many new ones. Our data represent a unique characterization of the p53-regulated response to ionizing radiation in vivo.
Project description:Once activated, B cells produce the antibodies needed to fight against infection. B cells are necessary for adaptive or specific immunity, which focuses on the destruction of foreign invaders that have gotten past the bodies initial defenses. Heat shock protein family is a group of highly conserved molecular chaperones with important functions in protein folding such as antibody and in signal transduction. Stch (Heat shock 70 kDa protein 13) is a member of the heat shock protein 70 family and is found associated with microsomes. Members of this protein family play a role in the processing of cytosolic and secretory proteins. To explore the role of Stch in B-cell activation and antibody production, we evaluated the transcriptional events and the role of stch pathway on the activation and antibody production of B cells by single cell RNAseq. Splenic lymphocytes were isolated from 7-9-week-old female Stchf/f wildtype (WT) mice and B-cell specific Stch knocked-out (CD19creStchf/f) mice (3 mice/group) using Ficoll (Ficoll-Paque Plus, GE Healthcre). B cells were sorted using B220 microbeads (Cat No. 130-049-501, Miltenyi Biotec, Germany). Their transcriptomes were captured using a 10x chromium system.
Project description:Transcription factor Ebf1 is an important determinant of early B lymphopoiesis. To gain insight into differentiation stage-specific functions of Ebf1, we conditionally inactivated Ebf1. We found that Ebf1 is required for proliferation, survival and signaling of pro-B cells and peripheral B cell subsets. The proliferation defect of Ebf1-deficient pro-B cells, including the impaired expression of IL-7Ra and several cell cycle regulators, is overcome by transformation with v-Abl. The survival defect of transformed Ebf1fl/fl pro-B cells can be rescued by the forced expression of the Ebf1 targets c-Myb or Bcl-xL. In mature B cells, Ebf1 deficiency interferes with the BAFF-R and BCR-dependent Akt signaling pathways, as well as with germinal center formation and class switch recombination. Genome-wide analyses of Ebf1 binding and Ebf1-mediated gene expression in mature B cells and comparison with reported data sets in pro-B cells provide insight into the basis for lineage- and stage-specific functions of Ebf1. Localistaion of histone modification (H3K4me2 and H3K4me3) in splenic B cells in mice by ChIP-seq
Project description:Radiation induced interferon response is mediated by IRF1 but not by the IRF3. Phosphorylated p53 binds strongly within 1kb of TTS of p53 dependent genes that are potently induced by ionizing radiation.
Project description:Genome-wide expression analysis comparison with and without ionizing radiation in p53 mutant and wild type Drosophila larvae Genome-wide expression analysis comparison with and without ionizing radiation in p53 mutant (p53^5A-1-4) and wild type (y^1 w^1118) Drosophila third instar larvae. 4000R of X-rays used in IR-treated Drosophila. Analyzed 2hr and 18hr after exposure with age-matched larvae in non-treated controls.