Project description:BET (bromodomain and extraterminal motif) proteins are pharmacologic targets for the treatment of diverse diseases, yet the roles of individual BET family members remain unclear. We find that BRD2 colocalizes with the architectural/insulator protein CCCTC-binding factor (CTCF) genome-wide. To test a role for BRD2 in chromatin architecture we performed HiC in uninduced G1E-ER4 cells (-GATA1), and compared it to HiC in BRD2-depleted G1E-ER4 cells
Project description:ChIP-seq of total Pol II in G1E ER4 cell line at time points after mitosis. Nocodazole arrest-release in G1E ER4 cell line under conditions of 13h estradiol treatment.
Project description:Tissue-specific transcription patterns are preserved throughout cell divisions to maintain lineage fidelity. We investigated whether transcription factor GATA1 plays a role in transmitting hematopoietic gene expression programs through mitosis when transcription is transiently silenced. Live cell imaging revealed that a fraction of GATA1 is retained focally within mitotic chromatin. ChIP-seq of highly purified mitotic cells uncovered that key hematopoietic regulatory genes are occupied by GATA1 in mitosis. The GATA1 co- regulators FOG1 and TAL1 dissociate from mitotic chromatin, suggesting that GATA1 functions as platform for their postmitotic recruitment. Mitotic GATA1 target genes tend to re-activate more rapidly upon entry into G1 than genes from which GATA1 dissociates. A novel system designed to destroy GATA1 specifically during mitosis revealed that mitotic occupancy is required for rapid target gene reactivation. These studies suggest a requirement of mitotic “bookmarking” by GATA1 for the faithful propagation of cell type-specific transcription programs through cell division GATA1 occupancy profiles in mitotic G1E-ER4 +E2 cells generated by ChIP-sequencing. ChIP input DNA was sequenced as control. Previously reported (GSE18164) GATA1 occupancy in asynchrnous G1E-ER4 +E2 cells was analysed and compared with mitotic GATA1 occupancy.
Project description:we mapped the locations of DNA segments occupied by GATA1 using chromatin immunoprecipitation (ChIP). We have produced genome-wide GATA1 ChIP datasets after restoration and activation in G1E-ER4 cells. we employed the sequence census methodology of ChIP-seq , using Illumina GA2 technology to produce 23 million reads (36 nucleotides long) uniquely mapped to the mouse genome (mm8 assembly) for the GATA1 ChIP DNA and 15 million mapped reads for the input DNA
Project description:we mapped the locations of DNA segments occupied by GATA1 using chromatin immunoprecipitation (ChIP). We have produced genome-wide GATA1 ChIP datasets after restoration and activation in G1E-ER4 cells. we employed the sequence census methodology of ChIP-seq , using Illumina GA2 technology to produce 23 million reads (36 nucleotides long) uniquely mapped to the mouse genome (mm8 assembly) for the GATA1 ChIP DNA and 15 million mapped reads for the input DNA Examination of transcription factor GATA1 occupancy
Project description:ChIP-seq of H3K27Ac in the G1E-ER4 cell line in prometaphase (nocodazole block), between anaphase-telophase (nocodazole release 40min), and interphase (asynchronous). Nocodazole arrest-release in G1E ER4 cell line under conditions of 13h estradiol treatment.
Project description:Analysis of erythroid differentiation using Gata1 gene-disrupted G1E ER4 clone cells. Estradiol addition activates an ectopically expressed Gata-1-estrogen receptor fusion protein, triggering synchronous differentiation. 30 hour time course corresponds roughly to late burst-forming unit-erythroid stage (t=0 hrs) through orthochromatic erythroblast stage (t=30 hrs). Experiment Overall Design: G1E ER4 cells cultured in G1E medium were treated at 6 time points with estradiol to initiate erythroid differentiation by activating Gata1 transcription factor and total RNAs from treated cells were extracted for microarray experiment. The erythroid differentiation status was confirmed by cell pellet color and expression of microRNA miR451. The design was similar to an earlier studies (Welch, J. J., Watts, J. A., Vakoc, C. R., Yao, Y., Wang, H., Hardison, R. C., Blobel, G. A., Chodosh, L. A., and Weiss, M. J. (2004)). Global regulation of erythroid gene expression by transcription factor GATA-1. Blood 104, 3136-3147), except that a more recent version of Affymetric chip was used to acheive greater transcriptome coverage.
Project description:Interplays among lineage specific nuclear proteins, chromatin modifying enzymes and the basal transcription machinery govern cellular differentiation, but their dynamics of actions and coordination with transcriptional control are not fully understood. Alterations in chromatin structure appear to establish a permissive state for gene activation at some loci but they play an integral role in activation at other loci. To determine the predominant roles of chromatin states and factor occupancy in directing gene regulation during differentiation, we mapped chromatin accessibility, histone modifications, and nuclear factor occupancy genome-wide during mouse erythroid differentiation dependent on the master regulatory transcription factor GATA1. Remarkably, despite extensive changes in gene expression, the chromatin state profiles (proportions of a gene in a chromatin state dominated by activating or repressive histone modifications) and accessibility remain largely unchanged during GATA1-induced erythroid differentiation. In contrast, gene induction and repression are strongly associated with changes in patterns of transcription factor occupancy. Our results indicate that during erythroid differentiation, the broad features of chromatin states are established at the stage of lineage commitment, largely independently of GATA1. These determine permissiveness for expression, with subsequent induction or repression mediated by distinctive combinations of transcription factors. Using ChIP-Seq technology to examine DNase hypersensitivity, three transcription factors, and four histone modifications in Gata1-null murine G1E line and rescued G1E-ER4 subline, and also two of the transcription factors in mouse primary erythroblasts. ChIP input DNA was sequenced in each cell type as controls.