Project description:The centromere-specific Histone H3-variant CENH3 (also known as CENP-A) is considered to be an epigenetic mark for establishment and propagation of centromere identity. Pulse-induction of CENH3 (Drosophila CID) in Schneider S2 cells incorporates into noncentromeric regions and generates CID islands that resist clearing from chromosome arms for multiple cell generations. We demonstrate that CID islands represent functional ectopic kinetochores, which are non-randomly distributed on the chromosome and display a preferential localization near telomeres and pericentric heterochromatin in transcriptionally silent, intergenic chromatin domains. Although overexpression of heterochromatin protein 1 (HP1) or increasing Histone acetylation interferes with CID islands formation on a global scale, induction of a locally defined region of synthetic heterochromatin by targeting HP1-LacI fusions to stably integrated Lac Operator arrays produces a proximal hotspot for CID islands formation. These data suggest that the characteristics of regions bordering heterochromatin promote de novo kinetochore assembly and thereby contribute to centromere identity. ArrayExpress Release Date: 2011-07-15 Person Roles: submitter Person Last Name: Diehl Person First Name: Sarah Person Mid Initials: Person Email: diehl@immunbio.mpg.de Person Phone: (+49) 761 5108 795 Person Address: Stuebeweg 51, 79108 Freiburg im Breisgau, Germany Person Affiliation: Max-Planck-Institute for Immunobiology and Epigenetics Person Roles: investigator Person Last Name: Heun Person First Name: Patrick Person Mid Initials: Person Email: heun@immunbio.mpg.de Person Phone: (+49) 761 5108 717 Person Address: Stuebeweg 51, 79108 Freiburg im Breisgau, Germany Person Affiliation: Max-Planck-Institute for Immunobiology and Epigenetics Publication Title: Heterochromatin boundaries are hotspots for de novo kinetochore formation. Publication Author List: Agata Olszak, Dominic van Essen, Antonio J. Pereira, Sarah Diehl, Thomas Manke, Helder Maiato, Simona Saccani and Patrick Heun
Project description:Tissue-specific methylation patterns suggest a role for CpG island methylation in differentiation and cell-type-specific gene regulation. We have profiled CpG island methylation in different cells of the immune cell lineage to investigate this role. MBD-affinity purification combined with next generation sequencing was used to analyse CpG island methylation in dendritic cells, B cells, Th1, Th2 and naïve T cells. ChIP-seq was carried out to determine RNA polymerase II binding sites in these cell types and this was compared to the methylation profiles obtained. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/ Abstract: We have profiled CpG island methylation in various immune system cell types and related this to gene expression in these cells.
Project description:The centromere-specific Histone H3-variant CENH3 (also known as CENP-A) is considered to be an epigenetic mark for establishment and propagation of centromere identity. Pulse-induction of CENH3 (Drosophila CID) in Schneider S2 cells incorporates into noncentromeric regions and generates CID islands that resist clearing from chromosome arms for multiple cell generations. We demonstrate that CID islands represent functional ectopic kinetochores, which are non-randomly distributed on the chromosome and display a preferential localization near telomeres and pericentric heterochromatin in transcriptionally silent, intergenic chromatin domains. Although overexpression of heterochromatin protein 1 (HP1) or increasing Histone acetylation interferes with CID islands formation on a global scale, induction of a locally defined region of synthetic heterochromatin by targeting HP1-LacI fusions to stably integrated Lac Operator arrays produces a proximal hotspot for CID islands formation. These data suggest that the characteristics of regions bordering heterochromatin promote de novo kinetochore assembly and thereby contribute to centromere identity.
Project description:The individualized treatment of tumors has always been an urgent problem in clinical practice. Organoids-on-a-chip can reflect the heterogeneity of tumors and is a good model for in vitro anticancer drug screening. In this study, surgical specimens of patients with advanced colorectal cancer will be collected for organoid culture and organoids-on-a- chip. Use organoids-on-a-chip to screen tumor chemotherapy drugs, compare the results of patients’ actual medication regimens, and study the guiding role of organoids in the formulation of precise tumor treatment plans. The investigators will compare the response of organoids to drugs in vitro with the patient’s response to actual chemotherapy and targeted drugs and explore the feasibility and accuracy of organoids-on-a-chip based drug screening for advanced colorectal cancer. The project will establish a screening platform for chemotherapeutic drugs and targeted drugs based on colorectal cancer organoids to quickly and accurately formulate personalized treatment plans for clinical patients.
Project description:Proteotoxicity from insufficient clearance of misfolded/damaged proteins underlies many diseases. Carboxyl terminus of Hsc70-interacting protein (CHIP) is an important regulator of proteostasis in many cells, having E3-ligase and chaperone functions and often directing damaged proteins towards proteasome recycling. While enhancing CHIP functionality has broad therapeutic potential, prior efforts have all relied on genetic upregulation. Here we demonstrate that CHIP-mediated protein turnover is markedly post-translationally enhanced by direct protein kinase G (PKG) phosphorylation at S20 (mouse, S19 human). This increases CHIP binding affinity to Hsc70, CHIP protein halflife, and consequent clearance of stress-induced ubiquitinated-insoluble proteins. PKGmediated CHIP-pS20 or expressing CHIP-S20E (phosphomimetic) reduces ischemic proteo- and cytotoxicity, whereas a phospho-silenced CHIP-S20A amplifies both. In vivo, depressing PKG activity lowers CHIP-S20 phosphorylation and protein, exacerbating proteotoxicity and heart dysfunction after ischemic injury. CHIP-S20E knock-in mice better clear ubiquitinated proteins and are cardio-protected. PKG activation provides post-translational enhancement of protein quality control via CHIP.
Project description:We compare the methylation status of CpG island clones by MeDIP in SW48 colon cancer cells relative to normal colon mucosa and WI38 primary fibroblasts. Keywords: ordered
Project description:We compare the methylation status of CpG island clones by MeDIP in SW48 colon cancer cells relative to normal colon mucosa and WI38 primary fibroblasts.
Project description:The RNA polymerase II (RNApII) C-terminal domain (CTD)-interacting domain (CID) proteins are involved in two distinct termination pathways and recognize different phosphorylated forms of CTD. To investigate the role of differential CTDM-^VCID interactions in the choice of termination pathway, we altered the CTD-binding specificity of Nrd1 by domain swapping. ChIP-chip was performed to examine the effect of Nrd1 CID swapping on genome-wide RNA polymerase II (Rpb3 antibody, Neoclone) occupancy. Nrd1 with the CID from Rtt103 (Nrd1[CID-Rtt103]; strain YSB2445) causes read-through transcription at many genes, but can trigger termination where multiple Nrd1/Nab3-binding sites and serine 2 phosphorylated CTD co-exist.