Comparison of gene expression between wild-type and PTIP deficient chicken DT40 B cells
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ABSTRACT:
ORGANISM(S): Gallus gallus
PROVIDER: GSE18778 | GEO | 2009/10/28
SECONDARY ACCESSION(S): PRJNA121245
REPOSITORIES: GEO
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Project description:PTIP (Pax2 transactivation domain-interacting protein) is a nuclear protein containing six BRCT domains. It has been shown that PTIP affects gene expression by controlling the activity of the transcription factor Pax2 and histone H3 lysine 4 methyltransferase complexes. In addition to its role in transcriptional regulation, PTIP has been implicated in DNA damage response. To ask if the depletion of PTIP affects the expression level of genes encoding DNA damage response factors , we compared the whole transcripts between wild-type and PTIP deficient chicken DT40 B cell lines. The total RNAs were isolated from wild-type and PTIP deficient cells (PTIP-/-/-) using Sepasol®-RNA I (Nacalai tesque, Japan). The gene expression profiles were examined using Genechip® Chicken Genome Array (Affymetrix Cat #900590), by GeneticLab co. Ltd. Japan, following Genechip® protocol.
2009-10-27 | E-GEOD-18778 | biostudies-arrayexpress
Project description:Class-switch recombination (CSR) diversifies antibodies for productive immune responses while maintaining stability of the B cell genome. Transcription at the immunoglobulin heavy-chain (Igh) locus targets CSRassociated DNA damage and is promoted by the BRCT domain-containing PTIP protein. Although PTIP is a unique component of the MLL3/MLL4 chromatin-modifying complex, the mechanisms for how PTIP promotes transcription remain unclear. Here we dissect the minimal structural requirements of PTIP and its different protein complexes using quantitative proteomics in primary lymphocytes. We find that PTIP functions in transcription and CSR separately from its association with the MLL3/MLL4 complex and from its localization to sites of DNA damage. We identify a tandem BRCT domain of PTIP that is sufficient for CSR and identify PA1 as its main functional protein partner. Collectively, we provide genetic and biochemical evidence that a PTIP-PA1 subcomplex functions independently from the MLL3/MLL4 complex to mediate transcription during CSR. These results further our understanding of how multi-functional chromatin-modifying complexes are organized by subcomplexes that harbor unique and distinct activities.
2015-12-12 | GSE75930 | GEO
Project description:Class-switch recombination (CSR) diversifies antibodies for productive immune responses while maintaining stability of the B cell genome. Transcription at the immunoglobulin heavy-chain (Igh) locus targets CSRassociated DNA damage and is promoted by the BRCT domain-containing PTIP protein. Although PTIP is a unique component of the MLL3/MLL4 chromatin-modifying complex, the mechanisms for how PTIP promotes transcription remain unclear. Here we dissect the minimal structural requirements of PTIP and its different protein complexes using quantitative proteomics in primary lymphocytes. We find that PTIP functions in transcription and CSR separately from its association with the MLL3/MLL4 complex and from its localization to sites of DNA damage. We identify a tandem BRCT domain of PTIP that is sufficient for CSR and identify PA1 as its main functional protein partner. Collectively, we provide genetic and biochemical evidence that a PTIP-PA1 subcomplex functions independently from the MLL3/MLL4 complex to mediate transcription during CSR. These results further our understanding of how multi-functional chromatin-modifying complexes are organized by subcomplexes that harbor unique and distinct activities. Genome-wide analysis of histone modifications in PA1-WT and -KO mouse activated B cells
2015-12-12 | E-GEOD-75930 | biostudies-arrayexpress
Project description:During Drosophila development, Polycomb-group and Trithorax-group proteins function to ensure correct maintenance of transcription patterns by epigenetically repressing or activating target gene expression. To get a deep insight into the PcG and trxG pathways, we investigated a BRCT domain-containing protein called PTIP, which was generally identified as a transcriptional coactivator and belongs to the TRR complex. At the genome scale, we sorted given PTIP binding peaks into two groups: PTIP/TRR-cobound and PTIP/PC-cobound peaks. In particular, we found that PTIP mediates the molecular switch between H3K4me3/H3K27ac and H3K27me3 histone modifications at TRR or PC occupied regions. Thus, we suggest that PTIP is a mediator rather than a dedicated co-activator along PcG and trxG pathways. Our hypothesis is further supported by the genetic assay: PTIP interacts genetically with either PcG or TrxG in a dosage-dependent manner, suggesting that PTIP functions as a co-factor of PcG/TrxG proteins. In addition, in accordance with the analysis of ChIP-seq, these genetic interactions correlate with modified ectopic HOX protein levels in imaginal discs, which reveals an essential role for PTIP in PcG-mediated Hox gene repression. Hence, we reveal a novel role for PTIP in the epigenetic regulation of gene expression along PcG and trxG pathways.
2022-05-23 | GSE203601 | GEO
Project description:Methylation of histone H3 lysine 4 (H3K4me) at actively expressed, cell type-specific genes is established during development by the Trithorax group of epigenetic regulators. In mammals, the Trithorax family includes KMT2A-D (MLL1-4), a family of SET domain proteins that function in large complexes to impart mono-, di-, and trimethylation at H3K4. Individual KMT2s and their co-factors are essential for embryonic development and the establishment of correct gene expression patterns, presumably by demarcating the active and accessible regions of the genome in a cell specific and heritable manner. Despite the importance of H3K4me marks in development, little is known about the importance of histone methylation in maintaining gene expression patterns in fully differentiated and non-dividing cell types. In this report, we utilized an inducible cardiac-specific Cre driver to delete the PTIP protein, a key component of a H3K4me complex, and ask whether this activity is still required to maintain the phenotype of terminally differentiated cardiomyocytes. Our results demonstrate that reducing the H3K4me3 marks is sufficient to alter gene expression patterns and significantly augment systolic heart function. These results clearly show that maintenance of H3K4me3 marks is necessary for the stability of the transcriptional program in differentiated cells. The array we performed allowed us to identify genes that are regulated by PTIP and histone methylation. 8-week-old littermate mice on a mixed C57B6 and B6129 background were utilized. Three mice were on a background with a PTIP floxed allele and a wild type PTIP allele (PTIP+1, PTIP+2, PTIP+3). Three mice had a transgene that expresses a modified estrogen receptor -Cre recombinase fusion protein under the control of a cardiac-specific driver (alpha myosin heavy chain, Jackson Lab stock #005650) and a floxed PTIP allele and a null PTIP (PTIPKO1, PTIPKO2, PTIPKO3). Both groups of mice were injected with tamoxifen at 8 weeks of age. Tamoxifen deletes the floxed PTIP allele in the PTIPKO mice. 5 days after tamoxifen injection, RNA was harvested from left ventricle (LV) apices in both groups. RNA was then sent to the University of Michigan microarray facility core for analysis.
2010-03-06 | E-GEOD-20570 | biostudies-arrayexpress
Project description:PPARg and C/EBPa cooperate to control preadipocyte differentiation (adipogenesis). However, the factors that regulate PPARg and C/EBPa expression during adipogenesis remain largely unclear. Here we show PTIP, a protein that associates with histone H3K4 methyltransferases, regulates PPARg and C/EBPa expression in mouse embryonic fibroblasts (MEFs) and during preadipocyte differentiation. PTIP deletion in MEFs leads to marked decreases of PPARg expression and PPARg-stimulated C/EBPα expression. Further, PTIP is essential for induction of PPARg and C/EBPa expression during preadipocyte differentiation. Deletion of PTIP impairs the enrichment of H3K4 trimethylation and RNA polymerase II on PPARg and C/EBPa promoters. Accordingly, PTIP-/- MEFs and preadipocytes all show striking defects in adipogenesis. Furthermore, rescue of the adipogenesis defect in PTIP-/- MEFs requires co-expression of PPARg and C/EBPa. Finally, deletion of PTIP in brown adipose tissue significantly reduces tissue weight in mice. Thus, by regulating PPARg and C/EBPa expression, PTIP plays a critical role in adipogenesis.
2009-05-29 | GSE16263 | GEO
Project description:PPARg and C/EBPa cooperate to control preadipocyte differentiation (adipogenesis). However, the factors that regulate PPARg and C/EBPa expression during adipogenesis remain largely unclear. Here we show PTIP, a protein that associates with histone H3K4 methyltransferases, regulates PPARg and C/EBPa expression in mouse embryonic fibroblasts (MEFs) and during preadipocyte differentiation. PTIP deletion in MEFs leads to marked decreases of PPARg expression and PPARg-stimulated C/EBPα expression. Further, PTIP is essential for induction of PPARg and C/EBPa expression during preadipocyte differentiation. Deletion of PTIP impairs the enrichment of H3K4 trimethylation and RNA polymerase II on PPARg and C/EBPa promoters. Accordingly, PTIP-/- MEFs and preadipocytes all show striking defects in adipogenesis. Furthermore, rescue of the adipogenesis defect in PTIP-/- MEFs requires co-expression of PPARg and C/EBPa. Finally, deletion of PTIP in brown adipose tissue significantly reduces tissue weight in mice. Thus, by regulating PPARg and C/EBPa expression, PTIP plays a critical role in adipogenesis. To identify PTIP-regulated genes, immortalized PTIP conditional knockout PTIPflox/flox MEFs were infected with retroviruses expressing either Cre recombinase or vector alone. We prepared duplicated RNAs from either vector or Cre infected cells (PTIP+/+ or PTIP-/-) for 4 affymetrix microarrays.
2009-05-29 | E-GEOD-16263 | biostudies-arrayexpress
Project description:Programmed genetic rearrangements in lymphocytes require transcription at antigen receptor genes to promote accessibility for initiating double-strand break (DSB) formation critical for DNA recombination and repair. Here we show that activated B cells deficient in the PTIP component of the MLL3 (mixed-lineage leukemia 3) /MLL4 complex display impaired histone methylation (H3K4me3) and transcription initiation of downstream switch regions at the immunoglobulin heavy-chain (Igh) locus leading to defective immunoglobulin class-switching. We also show that PTIP accumulation at DSBs contributes to class-switch recombination (CSR) and genome stability independently from Igh switch transcription. These results demonstrate that PTIP promotes specific chromatin changes that control the accessibility of the Igh locus to CSR, and suggest a non-redundant role for the MLL3/MLL4 complex in altering antibody effector function. Genome-wide analysis of histone modifications, PTIP, and Pol II in PTIP-WT and PTIP-KO mouse activated B cells.
2010-08-25 | E-GEOD-20852 | biostudies-arrayexpress
Project description:The aim of experiment was to study on genome-wide level IRF4 target genes in chicken DT40 B cell line, by comparizon of gene expression profiles of IRF4-deficient DT40 cells with WT IRF4 DT40 cells .
2017-01-01 | GSE56165 | GEO
Project description:Glomerular RNA comparison between wild-type and podocyte specific deletion of the PTIP gene in 1 month old kidneys. The PTIP gene was deleted using a floxed allele and a Podocin-Cre driver strain. These mice develop protein urea by 3 months of age. This study was designed to find gene expression differences prior to the onset of the phenotype. A ptip floxed allele was crossed into the Podocin-Cre expressing strain to generate ptip fl/fl homozygous mice or ptip fl/- transheterozygous mice with or without the Cre expressing transgene. Animals were genotyped and assigend into two groups: Mutants with PTIP deletion (PTIP-) with the genotype ptip fl/fl:Pod-Cre or ptip fl/-:Pod-Cre or control mice (PTIP+) with either ptip fl/fl or ptip fl/-. Note that the floxed allele produced normal levels of wild-type PTIP protein. Kidneys were excised at 1 month of age. Glomeruli enriched fractions were generated by sieving of the tissue homogenates. RNA was prepared from glomerular enriched fractions.
2009-08-19 | E-GEOD-17709 | biostudies-arrayexpress