scholarly journals Genome-wide identification of in vivo Drosophila Engrailed-binding DNA fragments and related target genes

Development ◽  
2003 ◽  
Vol 130 (7) ◽  
pp. 1243-1254 ◽  
Author(s):  
P. J. Solano
2021 ◽  
Vol 9 (1) ◽  
pp. 6
Author(s):  
Narendra Pratap Singh ◽  
Bony De Kumar ◽  
Ariel Paulson ◽  
Mark E. Parrish ◽  
Carrie Scott ◽  
...  

Knowledge of the diverse DNA binding specificities of transcription factors is important for understanding their specific regulatory functions in animal development and evolution. We have examined the genome-wide binding properties of the mouse HOXB1 protein in embryonic stem cells differentiated into neural fates. Unexpectedly, only a small number of HOXB1 bound regions (7%) correlate with binding of the known HOX cofactors PBX and MEIS. In contrast, 22% of the HOXB1 binding peaks display co-occupancy with the transcriptional repressor REST. Analyses revealed that co-binding of HOXB1 with PBX correlates with active histone marks and high levels of expression, while co-occupancy with REST correlates with repressive histone marks and repression of the target genes. Analysis of HOXB1 bound regions uncovered enrichment of a novel 15 base pair HOXB1 binding motif HB1RE (HOXB1 response element). In vitro template binding assays showed that HOXB1, PBX1, and MEIS can bind to this motif. In vivo, this motif is sufficient for direct expression of a reporter gene and over-expression of HOXB1 selectively represses this activity. Our analyses suggest that HOXB1 has evolved an association with REST in gene regulation and the novel HB1RE motif contributes to HOXB1 function in part through a repressive role in gene expression.


2007 ◽  
Vol 73 (23) ◽  
pp. 7522-7530 ◽  
Author(s):  
Yanyan Huang ◽  
Christopher L. Leming ◽  
Mitsu Suyemoto ◽  
Craig Altier

ABSTRACT Pigs are a food-producing species that readily carry Salmonella but, in the great majority of cases, do not show clinical signs of disease. Little is known about the functions required by Salmonella to be maintained in pigs. We have devised a recombinase-based promoter-trapping strategy to identify genes with elevated expression during pig infection with Salmonella enterica serovar Typhimurium. A total of 55 clones with in vivo-induced promoters were selected from a genomic library of ∼10,000 random Salmonella DNA fragments fused to the recombinase cre, and the cloned DNA fragments were analyzed by sequencing. Thirty-one genes encoding proteins involved in bacterial adhesion and colonization (including bcfA, hscA, rffG, and yciR), virulence (metL), heat shock (hscA), and a sensor of a two-component regulator (hydH) were identified. Among the 55 clones, 19 were isolated from both the tonsils and the intestine, while 23 were identified only in the intestine and 13 only in tonsils. High temperature and increased osmolarity were identified as environmental signals that induced in vivo-expressed genes, suggesting possible signals for expression.


2013 ◽  
Vol 289 (3) ◽  
pp. 1313-1328 ◽  
Author(s):  
Preeti Ramadoss ◽  
Brian J. Abraham ◽  
Linus Tsai ◽  
Yiming Zhou ◽  
Ricardo H. Costa-e-Sousa ◽  
...  

Triiodothyronine (T3) regulates key metabolic processes in the liver through the thyroid hormone receptor, TRβ1. However, the number of known target genes directly regulated by TRβ1 is limited, and the mechanisms by which positive and especially negative transcriptional regulation occur are not well understood. To characterize the TRβ1 cistrome in vivo, we expressed a biotinylated TRβ1 in hypo- and hyperthyroid mouse livers, used ChIP-seq to identify genomic TRβ1 targets, and correlated these data with gene expression changes. As with other nuclear receptors, the majority of TRβ1 binding sites were not in proximal promoters but in the gene body of known genes. Remarkably, T3 can dictate changes in TRβ1 binding, with strong correlation to T3-induced gene expression changes, suggesting that differential TRβ1 binding regulates transcriptional outcome. Additionally, DR-4 and DR-0 motifs were significantly enriched at binding sites where T3 induced an increase or decrease in TRβ1 binding, respectively, leading to either positive or negative regulation by T3. Taken together, the results of this study provide new insights into the mechanisms of transcriptional regulation by TRβ1 in vivo.


2008 ◽  
Vol 28 (8) ◽  
pp. 2732-2744 ◽  
Author(s):  
Pantelis Hatzis ◽  
Laurens G. van der Flier ◽  
Marc A. van Driel ◽  
Victor Guryev ◽  
Fiona Nielsen ◽  
...  

ABSTRACT Wnt signaling activates gene expression through the induced formation of complexes between DNA-binding T-cell factors (TCFs) and the transcriptional coactivator β-catenin. In colorectal cancer, activating Wnt pathway mutations transform epithelial cells through the inappropriate activation of a TCF7L2/TCF4 target gene program. Through a DNA array-based genome-wide analysis of TCF4 chromatin occupancy, we have identified 6,868 high-confidence TCF4-binding sites in the LS174T colorectal cancer cell line. Most TCF4-binding sites are located at large distances from transcription start sites, while target genes are frequently “decorated” by multiple binding sites. Motif discovery algorithms define the in vivo-occupied TCF4-binding site as evolutionarily conserved A-C/G-A/T-T-C-A-A-A-G motifs. The TCF4-binding regions significantly correlate with Wnt-responsive gene expression profiles derived from primary human adenomas and often behave as β-catenin/TCF4-dependent enhancers in transient reporter assays.


2013 ◽  
Vol 33 (9) ◽  
pp. 1735-1745 ◽  
Author(s):  
Li-Lun Ho ◽  
Amit Sinha ◽  
Michael Verzi ◽  
Kathrin M. Bernt ◽  
Scott A. Armstrong ◽  
...  

Methylation of H3K79 is associated with chromatin at expressed genes, though it is unclear if this histone modification is required for transcription of all genes. Recent studies suggest that Wnt-responsive genes depend particularly on H3K79 methylation, which is catalyzed by the methyltransferase DOT1L. Human leukemias carrying MLL gene rearrangements show DOT1L-mediated H3K79 methylation and aberrant expression of leukemogenic genes. DOT1L inhibitors reverse these effects, but their clinical use is potentially limited by toxicity in Wnt-dependent tissues such as intestinal epithelium. Genome-wide positioning of the H3K79me2 mark in Lgr5 + mouse intestinal stem cells and mature intestinal villus epithelium correlated with expression levels of all transcripts and not with Wnt-responsive genes per se . Selective Dot1l disruption in Lgr5 + stem cells or in whole intestinal epithelium eliminated H3K79me2 from the respective compartments, allowing genetic evaluation of DOT1L requirements. The absence of methylated H3K79 did not impair health, intestinal homeostasis, or expression of Wnt target genes in crypt epithelium for up to 4 months, despite increased crypt cell apoptosis. Global transcript profiles in Dot1l -null cells were barely altered. Thus, H3K79 methylation is not essential for transcription of Wnt-responsive or other intestinal genes, and intestinal toxicity is not imperative when DOT1L is rendered inactive in vivo .


2017 ◽  
Author(s):  
Ioanna Pavlaki ◽  
Farah Alammari ◽  
Bin Sun ◽  
Neil Clark ◽  
Tamara Sirey ◽  
...  

ABSTRACTMany long non-coding RNAs (lncRNAs) are expressed during central nervous system (CNS) development, yet their in vivo roles and molecular mechanisms of action remain poorly understood. Paupar, a CNS expressed lncRNA, controls neuroblastoma cell growth by binding and modulating the activity of genome-wide transcriptional regulatory elements. We show here that Paupar transcript directly binds KAP1, an essential epigenetic regulatory protein, and thereby regulates the expression of shared target genes important for proliferation and neuronal differentiation. Paupar promotes KAP1 chromatin occupancy and H3K9me3 deposition at a subset of distal targets, through formation of a DNA binding ribonucleoprotein complex containing Paupar, KAP1 and the PAX6 transcription factor. Paupar-KAP1 genome-wide co-occupancy reveals a 4-fold enrichment of overlap between Paupar and KAP1 bound sequences. Furthermore, both Paupar and Kap1 loss of function in vivo accelerates lineage progression in the mouse postnatal subventricular zone (SVZ) stem cell niche and disrupts olfactory bulb neurogenesis. These observations provide important conceptual insights into the trans-acting modes of lncRNA-mediated epigenetic regulation, the mechanisms of KAP1 genomic recruitment and identify Paupar and Kap1 as regulators of SVZ neurogenesis.


Author(s):  
Fumihiko Takeuchi ◽  
Yi-Qiang Liang ◽  
Masato Isono ◽  
Michiko Tajima ◽  
Zong Hu Cui ◽  
...  

Despite remarkable progress made in human genome-wide association studies, there remains a substantial gap between statistical evidence for genetic associations and functional comprehension of the underlying mechanisms governing these associations. As a means of bridging this gap, we performed genomic analysis of blood pressure (BP) and related phenotypes in spontaneously hypertensive rats (SHR) and their sub-strain, stroke-prone SHR (SHRSP), both of which are unique genetic models of severe hypertension and cardiovascular complications. By integrating whole-genome sequencing, transcriptome profiling, genome-wide linkage scans (max n=1,415), fine congenic mapping (max n=8,704), pharmacological intervention and comparative analysis with transcriptome-wide association study (TWAS) datasets, we searched causal genes and causal pathways for the tested traits. The overall results validated the polygenic architecture of elevated BP compared with a non-hypertensive control strain, Wistar Kyoto rats (WKY); e.g., inter-strain BP differences between SHRSP and WKY could be largely explained by an aggregate of BP changes in seven SHRSP-derived consomic strains. We identified 26 potential target genes, including rat homologues of human TWAS loci, for the tested traits. In this study, we re-discovered 18 genes that had previously been determined to contribute to hypertension or cardiovascular phenotypes. Notably, five of these genes belong to the kallikrein-kinin/renin-angiotensin systems (KKS/RAS), where the most prominent differential expression between hypertensive and non-hypertensive alleles could be detected in rat Klk1 paralogues. In combination with a pharmacological intervention, we provide in vivo experimental evidence supporting the presence of key disease pathways, such as KKS/RAS, in a rat polygenic hypertension model.


2021 ◽  
pp. ASN.2021010101
Author(s):  
Zhiheng Liu ◽  
Yunjing Liu ◽  
Lin Dang ◽  
Meijuan Geng ◽  
Yongzhan Sun ◽  
...  

Background Genome-wide mapping of transcription factor (TF) binding sites is essential to identify a TF's direct target genes in kidney development and diseases. However, due to the cellular complexity of the kidney and limited numbers of a given cell type, it has been challenging to determine the binding sites of a TF in vivo. cAMP-response element-binding protein (CREB) is phosphorylated and hyperactive in autosomal dominant polycystic kidney disease (ADPKD). We focus on CREB as an example to profile genomic loci bound by a TF and to identify its target genes using low numbers of specific kidney cells. Methods Cleavage under targets and release using nuclease (CUT&RUN) assays were performed with Dolichos biflorus agglutinin (DBA)-positive tubular epithelial cells from normal and ADPKD mouse kidneys. Pharmacological inhibition of CREB with 666-15 and genetic inhibition with A-CREB were undertaken using ADPKD mouse models. Results CUT&RUN to profile genome-wide distribution of phosphorylated CREB (p-CREB) indicated correlation of p-CREB binding with active histone modifications (H3K4me3 and H3K27ac) in cystic epithelial cells. Integrative analysis with CUT&RUN and RNA-sequencing revealed CREB direct targets, including genes involved in ribosome biogenesis and protein synthesis. Pharmacological and genetic inhibition of CREB suppressed cyst growth in ADPKD mouse models. Conclusions CREB promotes cystogenesis by activating ribosome biogenesis genes. CUT&RUN, coupled with transcriptomic analysis, enables interrogation of TF binding and identification of direct TF targets from a low number of specific kidney cells.


2016 ◽  
Vol 36 (17) ◽  
pp. 2236-2245 ◽  
Author(s):  
Gerald O. Hunter ◽  
Melanie J. Fox ◽  
Whitney R. Smith-Kinnaman ◽  
Madelaine Gogol ◽  
Brian Fleharty ◽  
...  

In eukaryotes, the C-terminal domain (CTD) of Rpb1 contains a heptapeptide repeat sequence of (Y1S2P3T4S5P6S7)nthat undergoes reversible phosphorylation through the opposing action of kinases and phosphatases. Rtr1 is a conserved protein that colocalizes with RNA polymerase II (RNAPII) and has been shown to be important for the transition from elongation to termination during transcription by removing RNAPII CTD serine 5 phosphorylation (Ser5-P) at a selection of target genes. In this study, we show that Rtr1 is a global regulator of the CTD code with deletion ofRTR1causing genome-wide changes in Ser5-P CTD phosphorylation and cotranscriptional histone H3 lysine 36 trimethylation (H3K36me3). Using chromatin immunoprecipitation and high-resolution microarrays, we show thatRTR1deletion results in global changes in RNAPII Ser5-P levels on genes with different lengths and transcription rates consistent with its role as a CTD phosphatase. Although Ser5-P levels increase, the overall occupancy of RNAPII either decreases or stays the same in the absence ofRTR1. Additionally, the loss of Rtr1in vivoleads to increases in H3K36me3 levels genome-wide, while total histone H3 levels remain relatively constant within coding regions. Overall, these findings suggest that Rtr1 regulates H3K36me3 levels through changes in the number of binding sites for the histone methyltransferase Set2, thereby influencing both the CTD and histone codes.


2017 ◽  
Author(s):  
Emma E. Davenport ◽  
Tiffany Amariuta ◽  
Maria Gutierrez-Arcelus ◽  
Kamil Slowikowski ◽  
Harm-Jan Westra ◽  
...  

AbstractBackgroundCytokines are critical to human disease and are attractive therapeutic targets given their widespread influence on gene regulation and transcription. Defining the downstream regulatory mechanisms influenced by cytokines is central to defining drug and disease mechanisms. One promising strategy is to use interactions between expression quantitative trait loci (eQTLs) and cytokine levels to define target genes and mechanisms.ResultsIn a clinical trial for anti-IL-6 in patients with systemic lupus erythematosus we measured interferon (IFN) status, anti-IL-6 drug exposure and genome-wide gene expression at three time points (379 samples from 157 individuals). First, we show that repeat transcriptomic measurements increases the number of cis eQTLs identified compared to using a single time point by 64%. Then, after identifying 4,818 cis-eQTLs, we observed a statistically significant enrichment of in vivo eQTL interactions with IFN status (p<0.001 by permutation) and anti-IL-6 drug exposure (p<0.001). We observed 210 and 72 interactions for IFN and anti-IL-6 respectively (FDR<20%). Anti-IL-6 interactions have not yet been described while 99 of the IFN interactions are novel. Finally, we found transcription factor binding motifs interrupted by eQTL interaction SNPs, pointing to key regulatory mediators of these environmental stimuli and therefore potential therapeutic targets for autoimmune diseases. In particular, genes with IFN interactions are enriched for ISRE binding site motifs, while those with anti-IL-6 interactions are enriched for IRF4 motifs.ConclusionThis study highlights the potential to exploit clinical trial data to discover in vivo eQTL interactions with therapeutically relevant environmental variables.


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