Orphan nuclear receptor TR4 uses non-equivalent binding sites to regulate gene targets from proximal and distal transcriptional regulatory elements during human definitive erythropoiesis [ChIP-seq]
Ontology highlight
ABSTRACT: In this study, we resolved the genome-wide binding of TR4 in differentiating human erythroid cells by performing chromatin immunoprecipitation followed by next-generation sequencing (ChIP-seq). We found that TR4 preferentially binds to DR1 elements in the promoters of its target genes, and that the majority of these genes encode proteins that participate in fundamental biological functions such as mRNA processing, translation, RNA splicing and primary metabolic process. Interestingly, we also found an increased occurrence of other repeat element motifs (such as DR4, IR1 and ER6) at TR4-bound distal sites that are located more than 10 Kbp away from the nearest gene. This raises the tantalizing possibility that TR4 may heterodimerize with unique partners, including other nuclear receptors such as RXR, thus allowing TR4 to elicit unique transcriptional responses when acting at proximal (promoter) and distal (enhancer and silencer) regulatory sites during human erythropoiesis. Examination of TR4 genome wild binding in human erythroid cells, which are harvested at day 8, 11 and 14 during in vitro differentiation. Two replicates were included for each differentiation stage.
Project description:We knocked down TR4 expression by 2 lentiviral mediated vectors at day 11 of erythroid differentiation in order to identify TR4 downstream targets. Two lentiviruses and one empty control were used to knockdown TR4 expression. The cells were harvested at day 11 during erythroid differentiation.
Project description:We profiled the dynamic, comprehensive transcriptome during human erythroid differentiation in vitro. The erythroid cells at day 4, 8, 11 and 14 differentiation stages were harvested and sequenced by Illumia 72 bp paired-end sequencing format, respectively. Expression profiling of erythroid cells on differentiation days 4, 8, 11 and 14 and performed mRNA-seq on two biological replicates at each stage.
Project description:We knocked down TR4 expression by 2 lentiviral mediated vectors at day 11 of erythroid differentiation in order to identify TR4 downstream targets.
Project description:Commitment of hematopoietic stem cells to B lineage precursors and development of B lineage precursors into mature B cells is attained through the coordinated function of multiple signaling networks, which are in turn controlled through stringent functioning of stage-specific transcription factors. Here, we describe the essential role of Sox4, an HMG (high mobility group)-box-containing transactivator, in B cell development. In the absence of Sox4, differentiation from pre-pro B to pro-B, from pro-B fraction B to pro-B fraction C and further to the immature B cell stage was severely impaired. Loss of differentiation was associated with reduced expression of Rag1 and Rag2 and markedly reduced DJ (diverse, joining) and VDJ (variable DJ) recombination at immunoglobulin heavy chain gene loci. We uncovered Sox4-regulated transcriptional circuits and a landscape of Sox4-chromatin interactions in pro-B cells. Sox4 ensured the negative regulation of Wnt signaling, which is critical for self-renewal of hematopoietic stem cells and early progenitors, by inducing one of its downstream effectors, casein kinase 1 epsilon. Our findings suggest that Sox4 orchestrates a unique transcriptional program and coordinates multilevel control in the differentiation of early-stage B cells. One sample of BAP-Sox4 bioChIP DNA and one sample of BAP-Sox4 input chromatin DNA were used.
Project description:We found that LSD1 inhibition by a monoamine oxidase inhibitor, tranylcypromine (TC), could enhance fetal gamma globin expression. Global effects of TC on erythroid expession were conducted by HG-U219 array strips. Primary human erythroid cells, which differentiated from CD34+ cells for 8 days, were harvested before or and after TC treatment (0.5 µM, 1.5 µM or 5 µM) for the gene expression analysis.
Project description:The orphan nuclear receptor TR4 (human testicular receptor 4 or NR2C2) plays a pivotal role in a variety of biological and metabolic processes. With no known ligand and few known target genes, the mode of TR4 function was unclear. We report the first genome-wide identification and characterization of TR4 in vivo binding. Using chromatin immunoprecipitation followed by high throughput sequencing (ChIP-seq), we identified TR4 binding sites in 4 different human cell types and found that the majority of target genes were shared among different cells. TR4 target genes are involved in fundamental biological processes such as RNA metabolism and protein translation. In addition, we found that a subset of TR4 target genes exerts cell-type specific functions. Analysis of the TR4 binding sites revealed that less than 30% of the peaks from any of the cell types contained the DR1 motif previously derived from in vitro studies, suggesting that TR4 may be recruited to the genome via interaction with other proteins. A bioinformatics analysis of the TR4 binding sites predicted a cis regulatory module involving TR4 and ETS transcription factors. To test this prediction, we performed ChIP-seq for the ETS factor ELK4 and found that 30% of TR4 binding sites were also bound by ELK4. Motif analysis of the sites bound by both factors revealed a lack of the DR1 element, suggesting that TR4 binding at a subset of sites is facilitated through the ETS transcription factor ELK4. Further studies will be required to investigate the functional interdependence of these two factors. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf 8 total ChIP-seq datasets; four TR4 and datasets done in duplicate from 4 different cell lines; ELK4 (Sap1a) duplicate dataset done from HeLa cells; 1 ELK1 replicate in HeLa cells, 2 individual replicates for histone mod datasets from K562 cells
Project description:In this study, we resolved the genome-wide binding of TR4 in differentiating human erythroid cells by performing chromatin immunoprecipitation followed by next-generation sequencing (ChIP-seq). We found that TR4 preferentially binds to DR1 elements in the promoters of its target genes, and that the majority of these genes encode proteins that participate in fundamental biological functions such as mRNA processing, translation, RNA splicing and primary metabolic process. Interestingly, we also found an increased occurrence of other repeat element motifs (such as DR4, IR1 and ER6) at TR4-bound distal sites that are located more than 10 Kbp away from the nearest gene. This raises the tantalizing possibility that TR4 may heterodimerize with unique partners, including other nuclear receptors such as RXR, thus allowing TR4 to elicit unique transcriptional responses when acting at proximal (promoter) and distal (enhancer and silencer) regulatory sites during human erythropoiesis.
Project description:Understanding factors that drive development and function of the sinoatrial node (SAN) is crucial to development of potential therapies for sinus arrhythmias, including potential generation of biological pacemakers. Here, we identify a key cell autonomous role for the LIM homeodomain transcription factor ISL1 for survival, proliferation and function of pacemaker cells throughout development. Chromatin immunoprecipitation assays performed utilizing antibody to ISL1 in chromatin extracts from FACS purified SAN cells demonstrated that ISL1 directly binds genomic regions within several genes critical for normal pacemaker function, including subunits of the L-type calcium channel, Ank2, and Tbx3. Other genes implicated in abnormal heart rhythm in humans were also direct downstream targets of ISL1 in SAN cells. Our studies represent the first in vivo ChIP-seq studies for SAN cells which provide a basis for further exploration of factors critical to SAN formation and function and highlight the potential for utilization of ISL1 in combination with other SAN transcription factors for generating pacemaker cells for therapy or drug screening purposes. ISL1 ChIP-seq profiling was performed in Hcn4-H2BGFP SAN cells purified from neonatal hearts.
Project description:Genetic control of pluripotent mammalian ES cells is determined by a transcriptional network, with a "central core" of transcription factors, Pou5f1, Sox2 and Nanog. Zebrafish homologues of the "core pluripotency factors" Pou5f1, SoxB1 and Nanog-like are also crucially involved in early development. However, the degree of functional similarity of the network between mammals and non-mammals is a matter of debate. To identify the components of Pou5f1-dependent transcriptional networks, we determined the genomic binding sites for Pou5f1 and Sox2 in late blastula stage zebrafish embryos using ChIP-seq. We found that Sox2 and Pou5f1 are co-binding to the regulatory regions of Sox2, Pou5f1, and Nanog-like, as well as to multiple orthologues of mammalian plutipotency network components. Deep sequencing was performed using the Illumina GAIIx on DNA samples obtained from Sox2 ChIP, Pou5f1-Flag ChIP and Input Control. Pou5f1 was analysed in technical duplicates to obtain higher sequencing depth.