scholarly journals hTFtarget: a comprehensive database for regulations of human transcription factors and their targets

2019 ◽  
Author(s):  
Qiong Zhang

Transcription factors (TFs) as key regulators play crucial roles in biological processes. The identification of TF-target regulatory relationships is a key step for revealing functions of TFs and their regulations on gene expression. The accumulated data of Chromatin immunoprecipitation sequencing (ChIP-Seq) provides great opportunities to discover the TF-target regulations across different conditions. In this study, we constructed a database named hTFtarget, which integrated huge human TF target resources (7,190 ChIP-Seq samples of 659 TFs and high confident TF binding sites of 699 TFs) and epigenetic modification information to predict accurate TF-target regulations. hTFtarget offers the following functions for users to explore TF-target regulations: 1) Browse or search general targets of a query TF across datasets; 2) Browse TF-target regulations for a query TF in a specific dataset or tissue; 3) Search potential TFs for a given target gene or ncRNA; 4) Investigate co-association between TFs in cell lines; 5) Explore potential co-regulations for given target genes or TFs; 6) Predict candidate TFBSs on given DNA sequences; 7) View ChIP-Seq peaks for different TFs and conditions in genome browser. hTFtarget provides a comprehensive, reliable and user-friendly resource for exploring human TF-target regulations, which will be very useful for a wide range of users in the TF and gene expression regulation community. hTFtarget is available at http://bioinfo.life.hust.edu.cn/hTFtarget.

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 372 ◽  
Author(s):  
Delasa Aghamirzaie ◽  
Karthik Raja Velmurugan ◽  
Shuchi Wu ◽  
Doaa Altarawy ◽  
Lenwood S. Heath ◽  
...  

Motivation: The increasing availability of chromatin immunoprecipitation sequencing (ChIP-Seq) data enables us to learn more about the action of transcription factors in the regulation of gene expression. Even though in vivo transcriptional regulation often involves the concerted action of more than one transcription factor, the format of each individual ChIP-Seq dataset usually represents the action of a single transcription factor. Therefore, a relational database in which available ChIP-Seq datasets are curated is essential. Results: We present Expresso (database and webserver) as a tool for the collection and integration of available Arabidopsis ChIP-Seq peak data, which in turn can be linked to a user’s gene expression data. Known target genes of transcription factors were identified by motif analysis of publicly available GEO ChIP-Seq data sets. Expresso currently provides three services: 1) Identification of target genes of a given transcription factor; 2) Identification of transcription factors that regulate a gene of interest; 3) Computation of correlation between the gene expression of transcription factors and their target genes. Availability: Expresso is freely available at http://bioinformatics.cs.vt.edu/expresso/


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 550-550
Author(s):  
Marc A Kerenyi ◽  
Jessica Hsu ◽  
Zhen Shao ◽  
Stuart H Orkin

Abstract Abstract 550 Lysine specific demethylase 1 (LSD1) is a demethylase that acts on mono- and dimethylated H3K4 (H3K4me1/2). Consistent with H3K4me2 (an active marker of transcription) as a substrate, LSD1 is part of a core complex with the co-repressor, CoREST and HDAC1/2. Previously our lab demonstrated that regulation of hematopoietic differentiation depends in part on the interaction of the growth factor independent transcription factors (= Gfi1 and Gfi1b) with the LSD1/CoREST/HDAC complex. We generated a conditional knock out mouse for LSD1 (LSD1fl/fl) to study its roles in hematopoiesis. Inducible deletion of LSD1fl/fl mice in all hematopoietic lineages with Mx-Cre resulted in severe neutropenia. Flow cytometric analysis showed that LSD1fl/fl Mx-Cre mice lacked Gr-1high Mac-1high double positive mature neutrophilic granulocytes in the bone marrow and the peripheral blood; however, the frequency of Gr-1dim Mac-1high (mainly consisting of promyelocytes and myeloblasts but not mature neutrophils) increased in frequency. To reveal the mechanism responsible for the observed neutropenia, we performed global mRNA expression profiling and chromatin immunoprecipitation sequencing (ChIPSeq) for H3K4 methylation states in Gr-1dim Mac-1high cells from LSD1fl/fl Mx-Cre and LSD1fl/fl mice. Five hundred ninety-eight genes (412 up / 186 down; p≤0.01, 2-fold cutoff) were differentially expressed in the absence of LSD1. Although we did not detect changes in expression of established myeloid transcription factors, including Pu.1, C/EBPα, C/EBPε or Gfi1, gene set enrichment analysis (GSEA) of Gr-1dim Mac-1high cells from LSD1fl/fl Mx-Cre using gene signatures for mature myeloid cells clearly showed that LSD1 deficient Gr-1dim Mac-1high cells failed to display a gene signature of differentiated myeloid cells (NES: 1.88; p≤0.003). Among the most highly upregulated genes, we observed genes highly expressed in hematopoietic stem and progenitor cells (HSPCs; i.e.: CD34 36.2-fold; HoxA9 26.3-fold; Sca-1 10.8-fold; Meis 1 2.6-fold). Therefore we performed GSEA using signatures from HSPCs (encompassing over 200 genes); the stem/progenitor gene set was highly significantly enriched (NES: −1.9; p<10−4) in LSD1 deficient Gr-1dim Mac-1high cells. Chromatin immunoprecipitation sequencing did not reveal any global changes in the amount of H3K4me2/3 histone methylation, however many genes critical for HSPCs, including Meis1 and the entire HoxA gene locus, where more strongly H3K4me2/3 marked than in control cells, which is in concord with the gene expression data. To determine if LSD1 represses stem/progenitor genes in additional lineages, we analyzed the effects of LSD1 loss in erythroid cell development through breeding with EpoR-Cre. Wild type, as well as control embryos, were recovered at Mendalian ratios up to E12.5, but no live LSD1fl/fl EpoR-Cre embryos were observed after E15.5. At E13.5, LSD1-deficient embryos were smaller and paler as compared to control embryos. Flow cytometry revealed a severe differentiation defect at the transition from pro-erythroblasts to basophilic erythroblasts, resulting in a paucity of more mature erythroid cells. To unravel molecular mechanisms responsible for this deficit, we performed gene expression profiling of wild type and knock out CD71+ c-kit+ Ter119lo pro-erythroblasts. Again, we did not detect changes in the expression levels of established erythroid transcription factors, including Gata-1, Klf1, SCL/Tal1, NF-E1, Ldb1, Lmo2 or Myb. By GSEA analysis we observed that LSD1 deficient CD71+ c-kit+ Ter119lo pro-erythroblasts displayed higher expression of the hematopoietic stem and progenitor cell gene signatures (NES: −2.4; p<10−4), a finding strikingly similar to the data in myeloid cells. Therefore, LSD1 is required in multiple hematopoietic lineages to repress stem/progenitor gene expression programs in maturing cells. We propose that repression of these early programs is essential for subsequent hematopoietic differentiation. Disclosures: No relevant conflicts of interest to declare.


2020 ◽  
Author(s):  
Yuzhou Wang ◽  
Yu Zhang ◽  
Jiazhen Gong ◽  
Jianqiang Bao ◽  
Shisong Ma

ABSTRACTTranscription factors (TF) regulate cellular activities via controlling gene expression, but a predictive model describing how TFs quantitatively modulate human transcriptomes was lacking. We constructed a universal human gene expression predictor and utilized it to decode transcriptional regulation. Using 1613 TFs’ expression, the predictor reconstituted highly accurate transcriptomes for samples derived from a wide range of tissues and conditions. The predictor’s broad applicability indicated it had recapitulated the quantitative relationships between TFs and target genes ubiquitous across tissues. Significant interacting TF-target gene pairs were then extracted from the predictor and enabled downstream inference of TF regulators for diverse pathways involved in development, immunity, metabolism, and stress response. Thus, we present a novel approach to study human transcriptional regulation following the “understanding by modeling” principle.


2005 ◽  
Vol 22 (5) ◽  
pp. 575-586 ◽  
Author(s):  
GUANG-HUA PENG ◽  
SHIMING CHEN

The transcription factors, Otx2, Crx, Nrl, and Nr2e3, expressed by retinal photoreceptor cells are essential for photoreceptor gene expression, development, and maintenance. Malfunction of any of these factors due to genetic mutations causes photoreceptor disease. Protein–protein interaction studies suggest that these factors may form a regulatory network centered on Crx. To understand how these factors regulate photoreceptor gene transcription in vivo, we have employed chromatin immunoprecipitation (ChIP) assays to assess the ability of these proteins to bind to regulatory sequences of photoreceptor genes in the retina of wild-type and mutant mice with photoreceptor degeneration. This paper summarizes the advantages and limitations of ChIP, using examples from our studies to demonstrate how this technique has contributed to our understanding of the regulation of photoreceptor gene expression. We report that Crx, Otx2, Nrl, and Nr2e3 co-occupy the promoter/enhancer, but not the region 3′ of selected Crx target genes, in a retina-specific fashion. We identified Crx-dependent (Nr2e3) and Crx-independent (Otx2 and Nrl) target binding using Crx knockout mice (Crx−/−), suggesting that individual factors may use distinct mechanism(s) for binding and regulating target genes. Consistent with ChIP results, we also found that Otx2, a close family member of Crx, can activate the promoter of rod and cone genes in HEK293 cells, implicating Otx2 in regulating photoreceptor gene expression. These findings provide important information for understanding how photoreceptor transcription factors regulate photoreceptor gene expression and the mechanisms by which mutations in these factors cause transcriptional dysregulation and photoreceptor degeneration.


Genetics ◽  
2019 ◽  
Vol 212 (3) ◽  
pp. 729-742 ◽  
Author(s):  
Lena Annika Street ◽  
Ana Karina Morao ◽  
Lara Heermans Winterkorn ◽  
Chen-Yu Jiao ◽  
Sarah Elizabeth Albritton ◽  
...  

Condensins are evolutionarily conserved protein complexes that are required for chromosome segregation during cell division and genome organization during interphase. In Caenorhabditis elegans, a specialized condensin, which forms the core of the dosage compensation complex (DCC), binds to and represses X chromosome transcription. Here, we analyzed DCC localization and the effect of DCC depletion on histone modifications, transcription factor binding, and gene expression using chromatin immunoprecipitation sequencing and mRNA sequencing. Across the X, the DCC accumulates at accessible gene regulatory sites in active chromatin and not heterochromatin. The DCC is required for reducing the levels of activating histone modifications, including H3K4me3 and H3K27ac, but not repressive modification H3K9me3. In X-to-autosome fusion chromosomes, DCC spreading into the autosomal sequences locally reduces gene expression, thus establishing a direct link between DCC binding and repression. Together, our results indicate that DCC-mediated transcription repression is associated with a reduction in the activity of X chromosomal gene regulatory elements.


2020 ◽  
Vol 86 (9) ◽  
Author(s):  
Gaili Fan ◽  
Huawei Zheng ◽  
Kai Zhang ◽  
Veena Devi Ganeshan ◽  
Stephen Obol Opiyo ◽  
...  

ABSTRACT The homeobox gene family of transcription factors (HTF) controls many developmental pathways and physiological processes in eukaryotes. We previously showed that a conserved HTF in the plant-pathogenic fungus Fusarium graminearum, Htf1 (FgHtf1), regulates conidium morphology in that organism. This study investigated the mechanism of FgHtf1-mediated regulation and identified putative FgHtf1 target genes by a chromatin immunoprecipitation assay combined with parallel DNA sequencing (ChIP-seq) and RNA sequencing. A total of 186 potential binding peaks, including 142 genes directly regulated by FgHtf1, were identified. Subsequent motif prediction analysis identified two DNA-binding motifs, TAAT and CTTGT. Among the FgHtf1 target genes were FgHTF1 itself and several important conidiation-related genes (e.g., FgCON7), the chitin synthase pathway genes, and the aurofusarin biosynthetic pathway genes. In addition, FgHtf1 may regulate the cAMP-protein kinase A (PKA)-Msn2/4 and Ca2+-calcineurin-Crz1 pathways. Taken together, these results suggest that, in addition to autoregulation, FgHtf1 also controls global gene expression and promotes a shift to aerial growth and conidiation in F. graminearum by activation of FgCON7 or other conidiation-related genes. IMPORTANCE The homeobox gene family of transcription factors is known to be involved in the development and conidiation of filamentous fungi. However, the regulatory mechanisms and downstream targets of homeobox genes remain unclear. FgHtf1 is a homeobox transcription factor that is required for phialide development and conidiogenesis in the plant pathogen F. graminearum. In this study, we identified FgHtf1-controlled target genes and binding motifs. We found that, besides autoregulation, FgHtf1 also controls global gene expression and promotes conidiation in F. graminearum by activation of genes necessary for aerial growth, FgCON7, and other conidiation-related genes.


2019 ◽  
Author(s):  
Logan J. Everett ◽  
Wen Huang ◽  
Shanshan Zhou ◽  
Mary Anna Carbone ◽  
Richard F. Lyman ◽  
...  

SummaryA major challenge in modern biology is to understand how naturally occurring variation in DNA sequences affects complex organismal traits through networks of intermediate molecular phenotypes. Here, we performed deep RNA sequencing of 200 Drosophila Genetic Reference Panel inbred lines with complete genome sequences, and mapped expression quantitative trait loci for annotated genes, novel transcribed regions (most of which are long noncoding RNAs), transposable elements and microbial species. We identified host variants that affect expression of transposable elements, independent of their copy number, as well as microbiome composition. We constructed sex-specific expression quantitative trait locus regulatory networks. These networks are enriched for novel transcribed regions and target genes in heterochromatin and euchromatic regions of reduced recombination, and genes regulating transposable element expression. This study provides new insights regarding the role of natural genetic variation in regulating gene expression and generates testable hypotheses for future functional analyses.


2020 ◽  
Author(s):  
SK Reilly ◽  
SJ Gosai ◽  
A Gutierrez ◽  
JC Ulirsch ◽  
M Kanai ◽  
...  

AbstractCRISPR screens for cis-regulatory elements (CREs) have shown unprecedented power to endogenously characterize the non-coding genome. To characterize CREs we developed HCR-FlowFISH (Hybridization Chain Reaction Fluorescent In-Situ Hybridization coupled with Flow Cytometry), which directly quantifies native transcripts within their endogenous loci following CRISPR perturbations of regulatory elements, eliminating the need for restrictive phenotypic assays such as growth or transcript-tagging. HCR-FlowFISH accurately quantifies gene expression across a wide range of transcript levels and cell types. We also developed CASA (CRISPR Activity Screen Analysis), a hierarchical Bayesian model to identify and quantify CRE activity. Using >270,000 perturbations, we identified CREs for GATA1, HDAC6, ERP29, LMO2, MEF2C, CD164, NMU, FEN1 and the FADS gene cluster. Our methods detect subtle gene expression changes and identify CREs regulating multiple genes, sometimes at different magnitudes and directions. We demonstrate the power of HCR-FlowFISH to parse genome-wide association signals by nominating causal variants and target genes.


2017 ◽  
Vol 63 (2) ◽  
pp. 89-99 ◽  
Author(s):  
Maria C. Davis ◽  
Christopher A. Kesthely ◽  
Emily A. Franklin ◽  
Shawn R. MacLellan

Transcription is the first and most heavily regulated step in gene expression. Sigma (σ) factors are general transcription factors that reversibly bind RNA polymerase (RNAP) and mediate transcription of all genes in bacteria. σ Factors play 3 major roles in the RNA synthesis initiation process: they (i) target RNAP holoenzyme to specific promoters, (ii) melt a region of double-stranded promoter DNA and stabilize it as a single-stranded open complex, and (iii) interact with other DNA-binding transcription factors to contribute complexity to gene expression regulation schemes. Recent structural studies have demonstrated that when σ factors bind promoter DNA, they capture 1 or more nucleotides that are flipped out of the helical DNA stack and this stabilizes the promoter open-complex intermediate that is required for the initiation of RNA synthesis. This review describes the structure and function of the σ70 family of σ proteins and the essential roles they play in the transcription process.


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