Project description:Estrogen Receptor alpha (ERα) is a key driver of most breast cancers, and it is the target of endocrine therapies used in the clinic to treat women with ERα positive (ER+) breast cancer. The two methods ChIP-seq (chromatin immunoprecipitation coupled with deep sequencing) and RIME (Rapid Immunoprecipitation of Endogenous Proteins) have greatly improved our understanding of ERα function during breast cancer progression and in response to anti-estrogens. A critical component of both ChIP-seq and RIME protocols is the antibody that is used to pull down the bait protein. To date, most of the ChIP-seq and RIME experiments for the study of ERα have been performed using the sc-543 antibody from Santa Cruz Biotechnology. However, this antibody has been discontinued, thereby severely impacting the study of ERα in normal physiology as well as diseases such as breast cancer and ovarian cancer. Here, we compare the sc-543 antibody with other commercially available antibodies, and we show that 06-935 (EMD Millipore) and ab3575 (Abcam) antibodies can successfully replace the sc-543 antibody for ChIP-seq and RIME experiments.
Project description:FACT was discovered to be a repressor of transcription in mES cells. In addition, the murine endogenous retrovirus were repressed by various mechanisms. Hence, we examined the possibility for Ssrp1 as a repressor of MT2/MERVL.
Project description:This experiment sought to determine the chromatin structure and PRC2 occupancy at the promoters of all genes in mouse ESCs ChIP-seq for EZH2, SUZ12, and H3K27me3 were performed on WT E14 cells in 2 biological replicates each. In addition H3K27me3 ChIP-seq was also performed on a clone of E14 cells expressing a tagged version of EZH2, which for the purpose of this study was used as replicate #3.
Project description:Endogenous retroviruses (ERVs) were usually silenced by various histone modifications on histone H3 variants and respective histone chaperones in embryonic stem cells (ESCs). However, it is still unknown whether chaperones of other histones could repress ERVs. Here, we show that H2A/H2B histone chaperone FACT plays a critical role in silencing ERVs and ERV-derived cryptic promoters in ESCs. Loss of FACT component Ssrp1 activated MERVL whereas the re-introduction of Ssrp1 rescued the phenotype. Additionally, Ssrp1 interacted with MERVL and suppressed cryptic transcription of MERVL-fused genes. Remarkably, Ssrp1 interacted with and recruited H2B deubiquitinase Usp7 to Ssrp1 target genes. Suppression of Usp7 caused similar phenotypes as loss of Ssrp1. Furthermore, Usp7 acted by deubiquitinating H2Bub and thereby repressed the expression of MERVL-fused genes. Taken together, our study uncovers a unique mechanism by which FACT complex silences ERVs and ERV-derived cryptic promoters in ESCs.
Project description:Regions of H3.3 binding in WT and ATRX KO mouse ES cells were identified by ChIP seq Chip-seq experiements were performed in WT and ATRX KO E14 mouse ES cells
Project description:Endogenous retrovirus MERVL is specifically expressed in a minority of embryonic stem cells. To determine the restrain mechanism of MERVL, we knocked out Ssrp1 and analyzed the effect on the expression of transposable elements and coding genes. Ssrp1 further interacts with ubiquitin specific protease Usp7. We knocked down usp7 and analyzed the effect on the expression of MERVL. It turns out the deletion of ssrp1 or usp7 would lead to upregulation of MERVL. This study extends our understandings of the machanism by novel factors regulates MERVL.
Project description:We examined 3D chromatin structure in the absence of cohesin (Scc1-AID auxin-inducible degron) and a control line (E14-Tir1) and found that PRC1 core promoter component RING1B was one of the most enriched proteins. Hence, we performed calibrated ChIP-seq experiments on the control (E14-Tir1) and the Scc1-AID mESC lines with a spike in of HEK293 human cells to further study this relationship.
Project description:This study describes the epigenetic profiling of the X chromosome during X inactivation. It includes H3K4me3 and H3K27me3 ChIP-Seq profiles of male (E14) and female (LF2 and XT67E1) mouse ES cells, together with their differentiated derivatives (either 4d atRA or 10d EB). It also includes ChIP-chip profiles around the Xic on chromosome X of H3K4me3, H3K27me3, H3K9me2, H3K36me3, Pol II, TBP, H3-Core as well as expression, using male (E14) and female (LF2) mouse ES cells, together with their differentiated derivatives (either 4d atRA or 10d EB). Examination of two different histone modifications in 3 cell lines under 3 conditions using ChIP-Seq. Examination of five different histone modifications two transcription factors and gene expression under three conditions in 2 cell lines using ChIP-chip.
