Project description:We used chromatin immunoprecipitation-coupled to deep sequencing (ChIP-seq) to profile genome-wide locations of H3K4 trimethylation (H3K4me3) and H3K27 trimethylation (H3K27me3) epigenetic marks in SATB1-depleted MDA-MB-231 aggressive breast cells.
Project description:[PROJECT] After fertilization the embryonic genome is inactive until transcription is initiated during the maternal-zygotic transition (MZT). This universal process coincides with the formation of pluripotent cells, which in mammals can be used to generate embryonic stem (ES) cells. To study the changes in chromatin structure that accompany zygotic genome activation and pluripotency, we mapped the genomic locations of histone H3 modifications before and after MZT in zebrafish embryos. Repressive H3 lysine 27 trimethylation (H3K27me3) and activating H3 lysine 4 trimethylation (H3K4me3) are only detected after MZT. H3K4me3 marks more than 80% of genes, including many developmental regulatory genes that are also occupied by H3K27me3. Sequential chromatin immunoprecipitation demonstrates that both methylation marks occupy the same promoter regions, revealing that the bivalent chromatin domains found in cultured ES cells also exist in embryos. In addition, we find a large group of genes that are monovalently marked by H3K4me3 but not H3K27me3. These H3K4me3 monovalent genes are neither expressed nor stably bound by RNA polymerase II. Closer inspection of in vitro data sets reveals similar monovalent H3K4me3 domains in ES cells. The analysis of an inducible transgene indicates that H3K4me3 domains can form in the absence of sequence-specific transcriptional activators or stable association with RNA pol II. These results suggest that bivalent and monovalent domains might poise embryonic genes for activation and that the chromatin profile associated with pluripotency is established during MZT. [SAMPLES] ChIPchip analysis of histone modifications (H3K4me3, H3K27me3, H3K36me3) and RNA polymerase II in pre MZT (256-cell) and post MZT (4hpf; dome/30% epiboly) wt zebrafish embryos. H3K4me3, H3K27me3, H3K36me3 and PolII ChIP-chip at 256 cell stage (one replicate) and 4hpf (dome/30% epiboly) (two replicates)
Project description:Human embryonic stem (HUES) cells are derived from early individual embryos with unique genetic properties. However, how their epigenetic status might affect their potential to differentiate toward specific lineages remains a puzzling question. Using ChIP-on-chip, the status of bivalent domains on gene promoters (i.e. H3K4 and H3K27 trimethylation) was monitored for both undifferentiated and BMP2 induced cardiac committed cells. A marked difference in the epigenetic profile of HUES cell lines was observed and this was correlated to the pattern of gene expression induced by BMP2 as well as to their potential to generate cardiac progenitors and differentiated myocytes. Thus, the epigenetic H3trimeK4 and H3trimeK27 prints generating bivalent domains on promoters, could be used to predict a preference in their differentiation toward a specific lineage. Using ChIP-on-chip, the status of bivalent domains on gene promoters (i.e. H3K4 and H3K27 trimethylation) was monitored for both undifferentiated and BMP2 induced cardiac committed cells.
Project description:[PROJECT] After fertilization the embryonic genome is inactive until transcription is initiated during the maternal-zygotic transition (MZT). This universal process coincides with the formation of pluripotent cells, which in mammals can be used to generate embryonic stem (ES) cells. To study the changes in chromatin structure that accompany zygotic genome activation and pluripotency, we mapped the genomic locations of histone H3 modifications before and after MZT in zebrafish embryos. Repressive H3 lysine 27 trimethylation (H3K27me3) and activating H3 lysine 4 trimethylation (H3K4me3) are only detected after MZT. H3K4me3 marks more than 80% of genes, including many developmental regulatory genes that are also occupied by H3K27me3. Sequential chromatin immunoprecipitation demonstrates that both methylation marks occupy the same promoter regions, revealing that the bivalent chromatin domains found in cultured ES cells also exist in embryos. In addition, we find a large group of genes that are monovalently marked by H3K4me3 but not H3K27me3. These H3K4me3 monovalent genes are neither expressed nor stably bound by RNA polymerase II. Closer inspection of in vitro data sets reveals similar monovalent H3K4me3 domains in ES cells. The analysis of an inducible transgene indicates that H3K4me3 domains can form in the absence of sequence-specific transcriptional activators or stable association with RNA pol II. These results suggest that bivalent and monovalent domains might poise embryonic genes for activation and that the chromatin profile associated with pluripotency is established during MZT. [SAMPLES] ChIPchip analysis of histone modifications (H3K4me3, H3K27me3, H3K36me3) and RNA polymerase II in pre MZT (256-cell) and post MZT (4hpf; dome/30% epiboly) wt zebrafish embryos.
Project description:Lysine succinylation (Ksu) is a novel identified post-translational modification that conserved from prokaryote to eukaryotes. As a kind of acylation, Ksu was reported to have different functions with others acylation at lysine residue. However, recently studies on the Ksu mainly focus on the plants and bacterial, there are still very rare studies in the vertebrate. Therefore, the biological role of succinylation remains largely unknown in mammal. In this study, we performed global Ksu mapping in Danio rerio (zebrafish) using mass spectrometry-based proteomics with enrichment of Ksu peptides by immunoprecipitation technology. As a result, we totally identified 552 Ksu sites in 164 proteins. Compared with our previous studies on lysine acetylation and crotonylation, Ksu plays a major role in a diverse metabolic process, such as carbon metabolism and tricarboxylic acid circle. In addition, we defined 5 new succinylation motifs: (su)KA, (suc)KxxxxA, (su)KxxxxL, (su)KxA, (su)KxV. In conclusion, our result provides proteome-wide database for study of Ksu in zebrafish and our bioinformatics result facilitated the understanding of the Ksu in the role of central metabolism.