Double Chromatin Immunoprecipitation: Analysis of Target Co-occupancy of Retinal Transcription Factors

Author(s):  
Guang-Hua Peng ◽  
Shiming Chen
2006 ◽  
Vol 17 (2) ◽  
pp. 585-597 ◽  
Author(s):  
Fang Liu ◽  
Nabendu Pore ◽  
Mijin Kim ◽  
K. Ranh Voong ◽  
Melissa Dowling ◽  
...  

Histone deacetylases mediate critical cellular functions but relatively little is known about mechanisms controlling their expression, including expression of HDAC4, a class II HDAC implicated in the modulation of cellular differentiation and viability. Endogenous HDAC4 mRNA, protein levels and promoter activity were all readily repressed by mithramycin, suggesting regulation by GC-rich DNA sequences. We validated consensus binding sites for Sp1/Sp3 transcription factors in the HDAC4 promoter through truncation studies and targeted mutagenesis. Specific and functional binding by Sp1/Sp3 at these sites was confirmed with chromatin immunoprecipitation (ChIP) and electromobility shift assays (EMSA). Cotransfection of either Sp1 or Sp3 with a reporter driven by the HDAC4 promoter led to high activities in SL2 insect cells (which lack endogenous Sp1/Sp3). In human cells, restored expression of Sp1 and Sp3 up-regulated HDAC4 protein levels, whereas levels were decreased by RNA-interference-mediated knockdown of either protein. Finally, variable levels of Sp1 were in concordance with that of HDAC4 in a number of human tissues and cancer cell lines. These studies together characterize for the first time the activity of the HDAC4 promoter, through which Sp1 and Sp3 modulates expression of HDAC4 and which may contribute to tissue or cell-line-specific expression of HDAC4.


2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Yaling Feng ◽  
Jianxia Wang ◽  
Yue He ◽  
Heng Zhang ◽  
Minhui Jiang ◽  
...  

Abstract The present study aimed to unravel the molecular basis underlying PAX3 down-regulation, known to be involved in pre-eclampsia (PE) occurrence and development. Data obtained from databases suggested that Pax3 methylation levels in the promoter region are high in the placentas of PE patients. However, the expression of methylation-adjusting enzymes, including DNMT1, LSD1, and EZH2, did not change. Since lncRNAs enhance the function of methylation-related enzymes independently of expression, we selected three lncRNAs, RP11-269F21.2, DIAPH2-AS1, and RP11-445K13.2, predicted to interact with methylation-adjusting enzymes. Two transcription factors, HOXD8 and Lhx3, predicted to regulate the expression of lncRNAs, were also selected. Using RNA interference technology, HOXD8 and Lhx3 were found to positively regulate DIAPH2-AS1 and RP11-445K13.2 in HTR-8/SVneo cells. Chromatin immunoprecipitation assays determined that DIAPH2-AS1 recruited LSD1 to histone 3, increasing DNMT1 stability at H3. The HOXD8/DIAPH2-AS1 network regulated HTR-8/SVneo cell function under hypoxia by epigenetically regulating PAX3. This regulatory network may thus be responsible for PAX3 down-regulation in the placentas of PE patients.


2004 ◽  
Vol 279 (50) ◽  
pp. 52183-52190 ◽  
Author(s):  
Pascale Jackers ◽  
Gabor Szalai ◽  
Omar Moussa ◽  
Dennis K. Watson

Megakaryopoiesis is the process by which hematopoietic stem cells in the bone marrow differentiate into mature megakaryocytes. The expression of megakaryocytic genes during megakaryopoiesis is controlled by specific transcription factors. Fli-1 and GATA-1 transcription factors are required for development of megakaryocytes and promoter analysis has definedin vitrofunctional binding sites for these factors in several megakaryocytic genes, includingGPIIb,GPIX, andC-MPL. Herein, we utilize chromatin immunoprecipitation to examine the presence of Ets-1, Fli-1, and GATA-1 on these promotersin vivo. Fli-1 and Ets-1 occupy the promoters ofGPIIb,GPIX, andC-MPLgenes in both Meg-01 and CMK11-5 cells. WhereasGPIIbis expressed in both Meg-01 and CMK11-5 cells,GPIXandC-MPLare only expressed in the more differentiated CMK11–5 cells. Thus,in vivooccupancy by an Ets factor is not sufficient to promote transcription of some megakaryocytic genes. GATA-1 and Fli-1 are both expressed in CMK11-5 cells and co-occupy theGPIXandC-MPLpromoters. Transcription of all three megakaryocytic genes is correlated with the presence of acetylated histone H3 and phosphorylated RNA polymerase II on their promoters. We also show that exogenous expression of GATA-1 in Meg-01 cells leads to the expression of endogenous c-mpl and gpIX mRNA. WhereasGPIIb,GPIX, andC-MPLare direct target genes for Fli-1, both Fli-1 and GATA-1 are required for formation of an active transcriptional complex on theC-MPLandGPIXpromotersin vivo. In contrast,GPIIbexpression appears to be independent of GATA-1 in Meg-01 cells.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4214-4214
Author(s):  
Richard Dahl ◽  
Kristin S. Owens

Abstract Gfi-1 −/− mice generate abnormal immature myeloid cells exhibiting characteristics of both monocytes and granulocytes. One of Gfi-1’s critical functions is to downregulate monocyte specific genes in order for granulocytes to develop properly. Since the transcription factors C/EBP alpha and C/EBP epsilon are needed for granulocyte development we hypothesized that these factors may regulate Gfi-1 expression. The Gfi-1 promoter contains several putative C/EBP binding sites and we show by electrophoretic mobility shift and chromatin immunoprecipitation that C/EBP family members can bind to some of these sites. However we were unable to see activation of the Gfi-1 promoter by C/EBP proteins in transient transfection reporter assays. Other groups have shown that C/EBP proteins can synergize with the transcription factor c-myb. We observed that the Gfi-1 promoter contains sites for the hematopoietic transcription factor c-myb. Sevral of these c-myb binding sites are adjacent to C/EBP binding sites. In reporter assays in non-hematopoietic cells c-myb activated the Gfi-1 promoter by itself and this activity was enhanced when we included either C/EBP alpha or epsilon in the transfection. Our data suggests that C/EBP proteins and c-myb regulate the transcription of Gfi-1 in myeloid cells.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 661-661
Author(s):  
Vit Pospisil ◽  
Juraj Kokavec ◽  
Pavel Burda ◽  
Nikola Curik ◽  
Arthur I. Skoultchi ◽  
...  

Abstract PU.1 (Sfpi1) is an ets family transcription factor required for the proper generation of both myeloid (macrophages and neutrophils) and lymphoid lineages (B and T lymphocytes)(Scott 1994, McKercher 1996). Graded expression of exogenous PU.1 in murine PU.1-deficient fetal liver hematopoietic progenitors demonstrated that increased levels of PU.1 are required to initiate development of macrophages (DeKoter, 2000). We have studied the effects of graded expression of PU.1 on its occupancy in chromatin and on the development of myeloid cells in vitro. We measured changes in gene expression, PU.1 occupancy and histone modifications in PU.1-null hematopoietic progenitor cells stably expressing PU.1 fused to the ligand-binding domain of the estrogen receptor (PU.1-ER) (Walsh 2002). The level of active PU.1-ER was regulated with graded levels of the ER inducer tamoxifen. In vitro, intermediate levels of tamoxifen produced cells with granulocyte characteristics in the suspension cell fraction and macrophage-like characteristics in the attached fraction, whereas high levels of PU.1 produced mostly attached macrophage-like cells. Expression of granulocyte-specific PU.1 target mRNAs including gelatinase B (Mmp9) and myeloperoxidase (Mpo) were observed to be expressed only with intermediate levels of tamoxifen. In contrast, expression of macrophage PU.1 target mRNAs including Cd14, F4/80 and Cd68 mRNAs were observed to be gradually upregulated upon PU.1-ER activation, with the maximum expression at the highest levels of tamoxifen. Thus, the expression levels of PU.1 target genes and phenotypic characteristics of the cells are dependent on PU.1 levels. Interestingly, macrophage-like cells can be produced from granulocytic-like cells by changing tamoxifen levels and vice versa. Chromatin immunoprecipitation analysis revealed specific PU.1 occupancy within regulatory regions of the genes predominantly expressed in macrophages including Cd14 and Cd11b after treatment with high levels of tamoxifen. Specific PU.1 occupancy within regulatory regions of the granulocyte specific genes including MMP9 was observed at intermediate levels of tamoxifen. Suprisingly, chromatin immunoprecipitation analysis revealed specific PU.1 occupancy within regulatory regions of the lymphocytic PU.1 target genes including Interleukin-7 receptor (Il-7r) and RAG1 at intermediate levels of tamoxifen even though expression of these genes was not detected. Accumulation of acetylated K9 and methylated K4 of histone H3 in gene loci of macrophage and granulocytic markers such as Cd14, Cd11b, and Mmp9 correlated with their mRNA expression. However, lymphocyte-specific regulatory regions including that of Il-7r gene were hypoacetylated in H3K9 despite a marked PU.1 recruitment suggesting additional factors may be required for PU.1 mediated transactivation. To identify these molecules we have tested PU.1-dependent transcription factors: Egr2, Nab2, Cebpa and Gfi-1 and found that upon increasing PU.1 levels, expression of Egr2/Nab2 and Gfi-1/Cebpa changed in a reciprocal manner and these changes preceded expression of the lineage specific markers. We are currently testing if PU.1 directly regulates expression of Egr2, Nab2, Cebpa and Gfi-1 during granulocytic/macrophage differentiation.


2020 ◽  
Author(s):  
Sangrea Shim ◽  
Pil Joon Seo

SummaryEAT-UpTF (Enrichment Analysis Tool for Upstream Transcription Factors of a gene group) is an open-source Python script that analyzes the enrichment of upstream transcription factors (TFs) in a group of genes-of-interest (GOIs). EAT-UpTF utilizes genome-wide lists of TF-target genes generated by DNA affinity purification followed by sequencing (DAP-seq) or chromatin immunoprecipitation followed by sequencing (ChIP-seq). Unlike previous methods based on the two-step prediction of cis-motifs and DNA-element-binding TFs, our EAT-UpTF analysis enabled a one-step identification of enriched upstream TFs in a set of GOIs using lists of empirically determined TF-target [email protected] or [email protected]://github.com/sangreashim/EAT-UpTF


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/


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.


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.


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