Transposition of native chromatin for fast and sensitive epigenomic profiling of open chromatin, DNA-binding proteins and nucleosome position
ABSTRACT: We describe an assay for transposase-accessible chromatin using sequencing (ATAC-seq), based on direct in vitro transposition of sequencing adaptors into native chromatin, as a rapid and sensitive method for integrative epigenomic analysis. ATAC-seq captures open chromatin sites using a simple two-step protocol with 500–50,000 cells and reveals the interplay between genomic locations of open chromatin, DNA-binding proteins, individual nucleosomes and chromatin compaction at nucleotide resolution. We discovered classes of DNA-binding factors that strictly avoided, could tolerate or tended to overlap with the nucleosome. Using ATAC-seq maps of human CD4+ T cells from a proband obtained on consecutive days, we demonstrated the feasibility of analyzing an individual’s epigenome on a timescale compatible with clinical decision-making. We examined chromatin structure using ATAC-seq in 2 cell types (GM12878 cell line, purified CD4+ T cells).
Project description:To determine the ability of HNF4A and GATA6 to drive open chromatin formation, either HNF4A or GATA6 were overexpressed in normal oesophageal Het1A cells and ATAC-seq was performed.
Project description:Understanding the impact of cohesin mutations on HSPC chromatin structure We examined chromatin structure using ATAC-seq in CD34+ enriched-human HSPC that were transduced with either cohesin WT, mutant or empty vector controls
Project description:We used ATAC-seq (Buenrostro et al, 2013) to identify regions of open chromatin in FACS sorted mouse endothelial cells from E12.5 hearts. Please note that the animals were injected at different dates, which resulted in different effects of the knockout, as indicated in the batch attribute of the samples. This data set is part of the study "Endocardial Tbx20 is essential for mesenchymal and myocardial cell movements required for cardiac septation". Peaks were called using HOMER (-gsize 1.87e9 -region -tbp 1). Replicate 1: -fdr 1e-8, replicate 2: default parameters. Buenrostro JD, Giresi PG, Zaba LC, Chang HY, Greenleaf WJ. 2013. Transposition of native chromatin for fast and sensitive epigenomic profiling of open chromatin, DNA-binding proteins and nucleosome position. Nat Methods 10: 12138.
Project description:We surveyed the variation and dynamics of active regulatory elements genome-wide in CD4+ T cells, using Assay of Transposase Accessible Chromatin with sequencing (ATAC-seq) in longitudinal samples from healthy volunteers and during T cell activation. We created robust pipelines that enable accurate single molecule counting and allelic discrimination from clinical material. Over 4000 regulatory elements (7.2%) showed reproducible personal variation in activity. Gender was the most significant attributable source of regulome variation. ATAC-seq revealed novel elements that escape X chromosome inactivation and predicted gender-specific gene regulatory networks across autosomes, which coordinately impact genes with immune function. Noisy regulatory elements with personal variation in accessibility are significantly enriched for autoimmune disease loci. Over one third of regulome variation lacked genetic variation in cis, suggesting contributions from environmental or epigenetic factors. These results refine concepts of human individuality and provide foundational reference to compare disease-associated regulomes. We examined chromatin structure using ATAC-seq in purified human CD4+ T cells in 33 samples from 12 healthy donors and 15 samples from 3 patients with cutaneous T cell leukemia (CTCL). For T cell activation (TCA) time course, CD4+ cells from healthy donor 1 isolated as above were stimulated with ionomycin (1 ug/mL) and Phorbol Myristate Acetate (PMA; 20 ng/mL) and collected at 0, 1, 2, 4 hours in duplicate.
Project description:Assay for Transposable Accessible Chromatin (ATAC) reveals a genome wide view of areas of open chromatin at very high resolution, which are often associated with regulatory activity. The ATAC-seq technology uses a Tn5 transposase loaded with nex-generation sequencing primers in order to simultaneously fragment areas of open chromatin and ligate adapters.
Project description:B lymphopoiesis requires that immunoglobulin genes be accessible to RAG1-RAG2 recombinase. However, the RAG proteins bind widely to open chromatin, which suggests that additional mechanisms must restrict RAG-mediated DNA cleavage. Here we show that developmental downregulation of interleukin 7 (IL-7)-receptor signaling in small pre-B cells induced expression of the bromodomain-family member BRWD1, which was recruited to a specific epigenetic landscape at Igk dictated by pre–BCR-dependent Erk activation. BRWD1 enhanced RAG recruitment, increased gene accessibility and positioned nucleosomes 5′ to each Jκ recombination signal sequence. BRWD1 thus targets recombination to Igk and places recombination within the context of signaling cascades that control B cell development. Our findings represent a paradigm in which,at any particular antigen-receptor locus, specialized mechanisms enforce lineage- and stage-specific recombination. ChIP-seq for 1 transcription factor and 2 histone modifications in flow purified mouse small pre-B cells. ATAC-seq and RNA-seq in WT and Brwd-Mut mouse flow purified small pre-B cells.