1
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Xu C, Kleinschmidt H, Yang J, Leith EM, Johnson J, Tan S, Mahony S, Bai L. Systematic dissection of sequence features affecting binding specificity of a pioneer factor reveals binding synergy between FOXA1 and AP-1. Mol Cell 2024:S1097-2765(24)00529-X. [PMID: 39019045 DOI: 10.1016/j.molcel.2024.06.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/23/2024] [Accepted: 06/21/2024] [Indexed: 07/19/2024]
Abstract
Despite the unique ability of pioneer factors (PFs) to target nucleosomal sites in closed chromatin, they only bind a small fraction of their genomic motifs. The underlying mechanism of this selectivity is not well understood. Here, we design a high-throughput assay called chromatin immunoprecipitation with integrated synthetic oligonucleotides (ChIP-ISO) to systematically dissect sequence features affecting the binding specificity of a classic PF, FOXA1, in human A549 cells. Combining ChIP-ISO with in vitro and neural network analyses, we find that (1) FOXA1 binding is strongly affected by co-binding transcription factors (TFs) AP-1 and CEBPB; (2) FOXA1 and AP-1 show binding cooperativity in vitro; (3) FOXA1's binding is determined more by local sequences than chromatin context, including eu-/heterochromatin; and (4) AP-1 is partially responsible for differential binding of FOXA1 in different cell types. Our study presents a framework for elucidating genetic rules underlying PF binding specificity and reveals a mechanism for context-specific regulation of its binding.
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Affiliation(s)
- Cheng Xu
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA; Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, PA 16802, USA
| | - Holly Kleinschmidt
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA; Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, PA 16802, USA
| | - Jianyu Yang
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA; Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, PA 16802, USA
| | - Erik M Leith
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA; Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, PA 16802, USA
| | - Jenna Johnson
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Song Tan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA; Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, PA 16802, USA
| | - Shaun Mahony
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA; Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, PA 16802, USA
| | - Lu Bai
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA; Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, PA 16802, USA; Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA.
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2
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McCann AA, Baniulyte G, Woodstock DL, Sammons MA. Context dependent activity of p63-bound gene regulatory elements. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.593326. [PMID: 38766006 PMCID: PMC11100809 DOI: 10.1101/2024.05.09.593326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The p53 family of transcription factors regulate numerous organismal processes including the development of skin and limbs, ciliogenesis, and preservation of genetic integrity and tumor suppression. p53 family members control these processes and gene expression networks through engagement with DNA sequences within gene regulatory elements. Whereas p53 binding to its cognate recognition sequence is strongly associated with transcriptional activation, p63 can mediate both activation and repression. How the DNA sequence of p63-bound gene regulatory elements is linked to these varied activities is not yet understood. Here, we use massively parallel reporter assays (MPRA) in a range of cellular and genetic contexts to investigate the influence of DNA sequence on p63-mediated transcription. Most regulatory elements with a p63 response element motif (p63RE) activate transcription, with those sites bound by p63 more frequently or adhering closer to canonical p53 family response element sequences driving higher transcriptional output. The most active regulatory elements are those also capable of binding p53. Elements uniquely bound by p63 have varied activity, with p63RE-mediated repression associated with lower overall GC content in flanking sequences. Comparison of activity across cell lines suggests differential activity of elements may be regulated by a combination of p63 abundance or context-specific cofactors. Finally, changes in p63 isoform expression dramatically alters regulatory element activity, primarily shifting inactive elements towards a strong p63-dependent activity. Our analysis of p63-bound gene regulatory elements provides new insight into how sequence, cellular context, and other transcription factors influence p63-dependent transcription. These studies provide a framework for understanding how p63 genomic binding locally regulates transcription. Additionally, these results can be extended to investigate the influence of sequence content, genomic context, chromatin structure on the interplay between p63 isoforms and p53 family paralogs.
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Affiliation(s)
- Abby A. McCann
- Department of Biological Sciences and The RNA Institute, University at Albany, State University of New York. 1400 washington Ave, Albany, NY 12222
| | - Gabriele Baniulyte
- Department of Biological Sciences and The RNA Institute, University at Albany, State University of New York. 1400 washington Ave, Albany, NY 12222
| | - Dana L. Woodstock
- Department of Biological Sciences and The RNA Institute, University at Albany, State University of New York. 1400 washington Ave, Albany, NY 12222
| | - Morgan A. Sammons
- Department of Biological Sciences and The RNA Institute, University at Albany, State University of New York. 1400 washington Ave, Albany, NY 12222
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3
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Mukherjee A, Fallacaro S, Ratchasanmuang P, Zinski J, Boka A, Shankta K, Mir M. A fine kinetic balance of interactions directs transcription factor hubs to genes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.16.589811. [PMID: 38659757 PMCID: PMC11042322 DOI: 10.1101/2024.04.16.589811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Eukaryotic gene regulation relies on the binding of sequence-specific transcription factors (TFs). TFs bind chromatin transiently yet occupy their target sites by forming high-local concentration microenvironments (hubs and condensates) that increase the frequency of binding events. Despite their ubiquity, such microenvironments have been difficult to study in endogenous contexts due to technical limitations. Here, we overcome these limitations and investigate how hubs drive TF occupancy at their targets. Using a DNA binding perturbation to a hub-forming TF, Zelda, in Drosophila embryos, we find that hub properties, including the stability and frequencies of associations to targets, are key determinants of TF occupancy. Our data suggest that the targeting of these hubs is driven not just by specific DNA motif recognition, but also by a fine-tuned kinetic balance of interactions between TFs and their co-binding partners.
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Affiliation(s)
- Apratim Mukherjee
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
- Center for Computational and Genomic Medicine, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
| | - Samantha Fallacaro
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
- Center for Computational and Genomic Medicine, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
- Developmental, Stem Cell, and Regenerative Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Puttachai Ratchasanmuang
- Center for Computational and Genomic Medicine, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
- Howard Hughes Medical Institute, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
| | - Joseph Zinski
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
- Center for Computational and Genomic Medicine, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
| | - Alan Boka
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kareena Shankta
- Center for Computational and Genomic Medicine, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
- Roy and Diana Vagelos Program in Life Sciences and Management, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mustafa Mir
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
- Center for Computational and Genomic Medicine, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
- Howard Hughes Medical Institute, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
- Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
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4
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Gibson TJ, Larson ED, Harrison MM. Protein-intrinsic properties and context-dependent effects regulate pioneer factor binding and function. Nat Struct Mol Biol 2024; 31:548-558. [PMID: 38365978 PMCID: PMC11261375 DOI: 10.1038/s41594-024-01231-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 01/22/2024] [Indexed: 02/18/2024]
Abstract
Chromatin is a barrier to the binding of many transcription factors. By contrast, pioneer factors access nucleosomal targets and promote chromatin opening. Despite binding to target motifs in closed chromatin, many pioneer factors display cell-type-specific binding and activity. The mechanisms governing pioneer factor occupancy and the relationship between chromatin occupancy and opening remain unclear. We studied three Drosophila transcription factors with distinct DNA-binding domains and biological functions: Zelda, Grainy head and Twist. We demonstrated that the level of chromatin occupancy is a key determinant of pioneering activity. Multiple factors regulate occupancy, including motif content, local chromatin and protein concentration. Regions outside the DNA-binding domain are required for binding and chromatin opening. Our results show that pioneering activity is not a binary feature intrinsic to a protein but occurs on a spectrum and is regulated by a variety of protein-intrinsic and cell-type-specific features.
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Affiliation(s)
- Tyler J Gibson
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Elizabeth D Larson
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Melissa M Harrison
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
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5
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Yang Z, Li X, Sheng L, Zhu M, Lan X, Gu F. Multiomics-integrated deep language model enables in silico genome-wide detection of transcription factor binding site in unexplored biosamples. Bioinformatics 2024; 40:btae013. [PMID: 38216534 PMCID: PMC10812877 DOI: 10.1093/bioinformatics/btae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 12/07/2023] [Accepted: 01/11/2024] [Indexed: 01/14/2024] Open
Abstract
MOTIVATION Transcription factor binding sites (TFBS) are regulatory elements that have significant impact on transcription regulation and cell fate determination. Canonical motifs, biological experiments, and computational methods have made it possible to discover TFBS. However, most existing in silico TFBS prediction models are solely DNA-based, and are trained and utilized within the same biosample, which fail to infer TFBS in experimentally unexplored biosamples. RESULTS Here, we propose TFBS prediction by modified TransFormer (TFTF), a multimodal deep language architecture which integrates multiomics information in epigenetic studies. In comparison to existing computational techniques, TFTF has state-of-the-art accuracy, and is also the first approach to accurately perform genome-wide detection for cell-type and species-specific TFBS in experimentally unexplored biosamples. Compared to peak calling methods, TFTF consistently discovers true TFBS in threshold tuning-free way, with higher recalled rates. The underlying mechanism of TFTF reveals greater attention to the targeted TF's motif region in TFBS, and general attention to the entire peak region in non-TFBS. TFTF can benefit from the integration of broader and more diverse data for improvement and can be applied to multiple epigenetic scenarios. AVAILABILITY AND IMPLEMENTATION We provide a web server (https://tftf.ibreed.cn/) for users to utilize TFTF model. Users can train TFTF model and discover TFBS with their own data.
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Affiliation(s)
- Zikun Yang
- Damo Academy, Alibaba Group, Hangzhou 310023, China
- Hupan Lab, Hangzhou 310023, China
| | - Xin Li
- Damo Academy, Alibaba Group, Hangzhou 310023, China
- Hupan Lab, Hangzhou 310023, China
| | - Lele Sheng
- Damo Academy, Alibaba Group, Hangzhou 310023, China
- Hupan Lab, Hangzhou 310023, China
| | - Ming Zhu
- Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- MOE Key Laboratory of Bioinformatics, Tsinghua University, Beijing 100084, China
| | - Xun Lan
- Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- MOE Key Laboratory of Bioinformatics, Tsinghua University, Beijing 100084, China
| | - Fei Gu
- Damo Academy, Alibaba Group, Hangzhou 310023, China
- Hupan Lab, Hangzhou 310023, China
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6
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Brennan KJ, Weilert M, Krueger S, Pampari A, Liu HY, Yang AWH, Morrison JA, Hughes TR, Rushlow CA, Kundaje A, Zeitlinger J. Chromatin accessibility in the Drosophila embryo is determined by transcription factor pioneering and enhancer activation. Dev Cell 2023; 58:1898-1916.e9. [PMID: 37557175 PMCID: PMC10592203 DOI: 10.1016/j.devcel.2023.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 05/09/2023] [Accepted: 07/13/2023] [Indexed: 08/11/2023]
Abstract
Chromatin accessibility is integral to the process by which transcription factors (TFs) read out cis-regulatory DNA sequences, but it is difficult to differentiate between TFs that drive accessibility and those that do not. Deep learning models that learn complex sequence rules provide an unprecedented opportunity to dissect this problem. Using zygotic genome activation in Drosophila as a model, we analyzed high-resolution TF binding and chromatin accessibility data with interpretable deep learning and performed genetic validation experiments. We identify a hierarchical relationship between the pioneer TF Zelda and the TFs involved in axis patterning. Zelda consistently pioneers chromatin accessibility proportional to motif affinity, whereas patterning TFs augment chromatin accessibility in sequence contexts where they mediate enhancer activation. We conclude that chromatin accessibility occurs in two tiers: one through pioneering, which makes enhancers accessible but not necessarily active, and the second when the correct combination of TFs leads to enhancer activation.
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Affiliation(s)
- Kaelan J Brennan
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Melanie Weilert
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Sabrina Krueger
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Anusri Pampari
- Department of Computer Science, Stanford University, Palo Alto, CA 94305, USA
| | - Hsiao-Yun Liu
- Department of Biology, New York University, New York, NY 10003, USA
| | - Ally W H Yang
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Jason A Morrison
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Timothy R Hughes
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | | | - Anshul Kundaje
- Department of Computer Science, Stanford University, Palo Alto, CA 94305, USA; Department of Genetics, Stanford University, Palo Alto, CA 94305, USA
| | - Julia Zeitlinger
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA; Department of Pathology & Laboratory Medicine, The University of Kansas Medical Center, Kansas City, KS 66160, USA.
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7
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Harrison MM, Marsh AJ, Rushlow CA. Setting the stage for development: the maternal-to-zygotic transition in Drosophila. Genetics 2023; 225:iyad142. [PMID: 37616526 PMCID: PMC10550319 DOI: 10.1093/genetics/iyad142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 07/18/2023] [Indexed: 08/26/2023] Open
Abstract
The zygote has a daunting task ahead of itself; it must develop from a single cell (fertilized egg) into a fully functioning adult with a multitude of different cell types. In the beginning, the zygote has help from its mother, in the form of gene products deposited into the egg, but eventually, it must rely on its own resources to proceed through development. The transfer of developmental control from the mother to the embryo is called the maternal-to-zygotic transition (MZT). All animals undergo this transition, which is defined by two main processes-the degradation of maternal RNAs and the synthesis of new RNAs from the zygote's own genome. Here, we review the regulation of the MZT in Drosophila, but given the broad conservation of this essential process, much of the regulation is shared among metazoans.
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Affiliation(s)
- Melissa M Harrison
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706USA
| | - Audrey J Marsh
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706USA
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8
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Nowling RJ, Njoya K, Peters JG, Riehle MM. Prediction accuracy of regulatory elements from sequence varies by functional sequencing technique. Front Cell Infect Microbiol 2023; 13:1182567. [PMID: 37600946 PMCID: PMC10433755 DOI: 10.3389/fcimb.2023.1182567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 07/10/2023] [Indexed: 08/22/2023] Open
Abstract
Introduction Various sequencing based approaches are used to identify and characterize the activities of cis-regulatory elements in a genome-wide fashion. Some of these techniques rely on indirect markers such as histone modifications (ChIP-seq with histone antibodies) or chromatin accessibility (ATAC-seq, DNase-seq, FAIRE-seq), while other techniques use direct measures such as episomal assays measuring the enhancer properties of DNA sequences (STARR-seq) and direct measurement of the binding of transcription factors (ChIP-seq with transcription factor-specific antibodies). The activities of cis-regulatory elements such as enhancers, promoters, and repressors are determined by their sequence and secondary processes such as chromatin accessibility, DNA methylation, and bound histone markers. Methods Here, machine learning models are employed to evaluate the accuracy with which cis-regulatory elements identified by various commonly used sequencing techniques can be predicted by their underlying sequence alone to distinguish between cis-regulatory activity that is reflective of sequence content versus secondary processes. Results and discussion Models trained and evaluated on D. melanogaster sequences identified through DNase-seq and STARR-seq are significantly more accurate than models trained on sequences identified by H3K4me1, H3K4me3, and H3K27ac ChIP-seq, FAIRE-seq, and ATAC-seq. These results suggest that the activity detected by DNase-seq and STARR-seq can be largely explained by underlying DNA sequence, independent of secondary processes. Experimentally, a subset of DNase-seq and H3K4me1 ChIP-seq sequences were tested for enhancer activity using luciferase assays and compared with previous tests performed on STARR-seq sequences. The experimental data indicated that STARR-seq sequences are substantially enriched for enhancer-specific activity, while the DNase-seq and H3K4me1 ChIP-seq sequences are not. Taken together, these results indicate that the DNase-seq approach identifies a broad class of regulatory elements of which enhancers are a subset and the associated data are appropriate for training models for detecting regulatory activity from sequence alone, STARR-seq data are best for training enhancer-specific sequence models, and H3K4me1 ChIP-seq data are not well suited for training and evaluating sequence-based models for cis-regulatory element prediction.
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Affiliation(s)
- Ronald J. Nowling
- Electrical Engineering and Computer Science, Milwaukee School of Engineering, Milwaukee, WI, United States
| | - Kimani Njoya
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - John G. Peters
- Electrical Engineering and Computer Science, Milwaukee School of Engineering, Milwaukee, WI, United States
| | - Michelle M. Riehle
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, United States
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9
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Gibson TJ, Harrison MM. Protein-intrinsic properties and context-dependent effects regulate pioneer-factor binding and function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.18.533281. [PMID: 37066406 PMCID: PMC10103944 DOI: 10.1101/2023.03.18.533281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Chromatin is a barrier to the binding of many transcription factors. By contrast, pioneer factors access nucleosomal targets and promote chromatin opening. Despite binding to target motifs in closed chromatin, many pioneer factors display cell-type specific binding and activity. The mechanisms governing pioneer-factor occupancy and the relationship between chromatin occupancy and opening remain unclear. We studied three Drosophila transcription factors with distinct DNA-binding domains and biological functions: Zelda, Grainy head, and Twist. We demonstrated that the level of chromatin occupancy is a key determinant of pioneering activity. Multiple factors regulate occupancy, including motif content, local chromatin, and protein concentration. Regions outside the DNA-binding domain are required for binding and chromatin opening. Our results show that pioneering activity is not a binary feature intrinsic to a protein but occurs on a spectrum and is regulated by a variety of protein-intrinsic and cell-type-specific features.
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Affiliation(s)
- Tyler J. Gibson
- Department of Biomolecular Chemistry, University of Wisconsin-Madison Madison, WI
| | - Melissa M. Harrison
- Department of Biomolecular Chemistry, University of Wisconsin-Madison Madison, WI
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10
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Abstract
The control of gene expression in eukaryotes relies on how transcription factors and RNA polymerases manipulate the structure of chromatin. These interactions are especially important in development as gene expression programs change. Chromatin generally limits the accessibility of DNA, and thus exposing sequences at regulatory elements is critical for gene expression. However, it is challenging to understand how transcription factors manipulate chromatin structure and the sequence of regulatory events. The Drosophila embryo has provided a powerful setting to directly observe the establishment and elaboration of chromatin features and experimentally test the causality of transcriptional events that are shared among many metazoans. The large embryo is tractable by live imaging, and a variety of well-developed tools allow the manipulation of factors during early development. The early embryo develops as a syncytium with rapid nuclear divisions and no zygotic transcription, with largely featureless chromatin. Thus, studies in this system have revealed the progression of genome activation triggered by pioneer factors that initiate DNA exposure at regulatory elements and the establishment of chromatin domains, including heterochromatin, the nucleolus, and nuclear bodies. The de novo emergence of nuclear structures in the early embryo reveals features of chromatin dynamics that are likely to be central to transcriptional regulation in all cells.
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Affiliation(s)
- Kami Ahmad
- Division of Basic Sciences, Fred Hutchinson Cancer Center, 1100 Fairview Ave. N., P.O. Box 19024, Seattle, WA 98109-1024, USA
| | - Steven Henikoff
- Division of Basic Sciences, Fred Hutchinson Cancer Center, 1100 Fairview Ave. N., P.O. Box 19024, Seattle, WA 98109-1024, USA
- Howard Hughes Medical Institute, 4000 Jones Bridge Road Chevy Chase, MD 20815-6789, USA
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11
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DeepSTARR predicts enhancer activity from DNA sequence and enables the de novo design of synthetic enhancers. Nat Genet 2022; 54:613-624. [PMID: 35551305 DOI: 10.1038/s41588-022-01048-5] [Citation(s) in RCA: 69] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 03/08/2022] [Indexed: 02/06/2023]
Abstract
Enhancer sequences control gene expression and comprise binding sites (motifs) for different transcription factors (TFs). Despite extensive genetic and computational studies, the relationship between DNA sequence and regulatory activity is poorly understood, and de novo enhancer design has been challenging. Here, we built a deep-learning model, DeepSTARR, to quantitatively predict the activities of thousands of developmental and housekeeping enhancers directly from DNA sequence in Drosophila melanogaster S2 cells. The model learned relevant TF motifs and higher-order syntax rules, including functionally nonequivalent instances of the same TF motif that are determined by motif-flanking sequence and intermotif distances. We validated these rules experimentally and demonstrated that they can be generalized to humans by testing more than 40,000 wildtype and mutant Drosophila and human enhancers. Finally, we designed and functionally validated synthetic enhancers with desired activities de novo.
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12
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Mauduit D, Taskiran II, Minnoye L, de Waegeneer M, Christiaens V, Hulselmans G, Demeulemeester J, Wouters J, Aerts S. Analysis of long and short enhancers in melanoma cell states. eLife 2021; 10:e71735. [PMID: 34874265 PMCID: PMC8691835 DOI: 10.7554/elife.71735] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 12/06/2021] [Indexed: 12/14/2022] Open
Abstract
Understanding how enhancers drive cell-type specificity and efficiently identifying them is essential for the development of innovative therapeutic strategies. In melanoma, the melanocytic (MEL) and the mesenchymal-like (MES) states present themselves with different responses to therapy, making the identification of specific enhancers highly relevant. Using massively parallel reporter assays (MPRAs) in a panel of patient-derived melanoma lines (MM lines), we set to identify and decipher melanoma enhancers by first focusing on regions with state-specific H3K27 acetylation close to differentially expressed genes. An in-depth evaluation of those regions was then pursued by investigating the activity of overlapping ATAC-seq peaks along with a full tiling of the acetylated regions with 190 bp sequences. Activity was observed in more than 60% of the selected regions, and we were able to precisely locate the active enhancers within ATAC-seq peaks. Comparison of sequence content with activity, using the deep learning model DeepMEL2, revealed that AP-1 alone is responsible for the MES enhancer activity. In contrast, SOX10 and MITF both influence MEL enhancer function with SOX10 being required to achieve high levels of activity. Overall, our MPRAs shed light on the relationship between long and short sequences in terms of their sequence content, enhancer activity, and specificity across melanoma cell states.
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Affiliation(s)
- David Mauduit
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
- KU Leuven, Department of Human Genetics KU LeuvenLeuvenBelgium
| | - Ibrahim Ihsan Taskiran
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
- KU Leuven, Department of Human Genetics KU LeuvenLeuvenBelgium
| | - Liesbeth Minnoye
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
- KU Leuven, Department of Human Genetics KU LeuvenLeuvenBelgium
| | - Maxime de Waegeneer
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
- KU Leuven, Department of Human Genetics KU LeuvenLeuvenBelgium
| | - Valerie Christiaens
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
- KU Leuven, Department of Human Genetics KU LeuvenLeuvenBelgium
| | - Gert Hulselmans
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
- KU Leuven, Department of Human Genetics KU LeuvenLeuvenBelgium
| | - Jonas Demeulemeester
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
- KU Leuven, Department of Human Genetics KU LeuvenLeuvenBelgium
- Cancer Genomics Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Jasper Wouters
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
- KU Leuven, Department of Human Genetics KU LeuvenLeuvenBelgium
| | - Stein Aerts
- VIB-KU Leuven Center for Brain & Disease ResearchLeuvenBelgium
- KU Leuven, Department of Human Genetics KU LeuvenLeuvenBelgium
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13
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Huang SK, Whitney PH, Dutta S, Shvartsman SY, Rushlow CA. Spatial organization of transcribing loci during early genome activation in Drosophila. Curr Biol 2021; 31:5102-5110.e5. [PMID: 34614388 DOI: 10.1016/j.cub.2021.09.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 07/19/2021] [Accepted: 09/09/2021] [Indexed: 10/20/2022]
Abstract
The early Drosophila embryo provides unique experimental advantages for addressing fundamental questions of gene regulation at multiple levels of organization, from individual gene loci to the entire genome. Using 1.5-h-old Drosophila embryos undergoing the first wave of genome activation,1 we detected ∼110 discrete "speckles" of RNA polymerase II (RNA Pol II) per nucleus, two of which were larger and localized to the histone locus bodies (HLBs).2,3 In the absence of the primary driver of Drosophila genome activation, the pioneer factor Zelda (Zld),1,4,5 70% fewer speckles were present; however, the HLBs tended to be larger than wild-type (WT) HLBs, indicating that RNA Pol II accumulates at the HLBs in the absence of robust early-gene transcription. We observed a uniform distribution of distances between active genes in the nuclei of both WT and zld mutant embryos, indicating that early co-regulated genes do not cluster into nuclear sub-domains. However, in instances whereby transcribing genes did come into close 3D proximity (within 400 nm), they were found to have distinct RNA Pol II speckles. In contrast to the emerging model whereby active genes are clustered to facilitate co-regulation and sharing of transcriptional resources, our data support an "individualist" model of gene control at early genome activation in Drosophila. This model is in contrast to a "collectivist" model, where active genes are spatially clustered and share transcriptional resources, motivating rigorous tests of both models in other experimental systems.
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Affiliation(s)
- Shao-Kuei Huang
- Department of Biology, New York University, New York, NY 10003, USA
| | - Peter H Whitney
- Department of Biology, New York University, New York, NY 10003, USA
| | - Sayantan Dutta
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Stanislav Y Shvartsman
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Center for Computational Biology, Flatiron Research Institute, New York, NY 10010, USA
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14
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The non-coding genome in genetic brain disorders: new targets for therapy? Essays Biochem 2021; 65:671-683. [PMID: 34414418 PMCID: PMC8564736 DOI: 10.1042/ebc20200121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 07/12/2021] [Accepted: 07/26/2021] [Indexed: 11/30/2022]
Abstract
The non-coding genome, consisting of more than 98% of all genetic information in humans and once judged as ‘Junk DNA’, is increasingly moving into the spotlight in the field of human genetics. Non-coding regulatory elements (NCREs) are crucial to ensure correct spatio-temporal gene expression. Technological advancements have allowed to identify NCREs on a large scale, and mechanistic studies have helped to understand the biological mechanisms underlying their function. It is increasingly becoming clear that genetic alterations of NCREs can cause genetic disorders, including brain diseases. In this review, we concisely discuss mechanisms of gene regulation and how to investigate them, and give examples of non-coding alterations of NCREs that give rise to human brain disorders. The cross-talk between basic and clinical studies enhances the understanding of normal and pathological function of NCREs, allowing better interpretation of already existing and novel data. Improved functional annotation of NCREs will not only benefit diagnostics for patients, but might also lead to novel areas of investigations for targeted therapies, applicable to a wide panel of genetic disorders. The intrinsic complexity and precision of the gene regulation process can be turned to the advantage of highly specific treatments. We further discuss this exciting new field of ‘enhancer therapy’ based on recent examples.
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15
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Colonnetta MM, Abrahante JE, Schedl P, Gohl DM, Deshpande G. CLAMP regulates zygotic genome activation in Drosophila embryos. Genetics 2021; 219:iyab107. [PMID: 34849887 PMCID: PMC8633140 DOI: 10.1093/genetics/iyab107] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/15/2020] [Indexed: 11/13/2022] Open
Abstract
Embryonic patterning is critically dependent on zygotic genome activation (ZGA). In Drosophila melanogaster embryos, the pioneer factor Zelda directs ZGA, possibly in conjunction with other factors. Here, we have explored the novel involvement of Chromatin-Linked Adapter for MSL Proteins (CLAMP) during ZGA. CLAMP binds thousands of sites genome-wide throughout early embryogenesis. Interestingly, CLAMP relocates to target promoter sequences across the genome when ZGA is initiated. Although there is a considerable overlap between CLAMP and Zelda binding sites, the proteins display distinct temporal dynamics. To assess whether CLAMP occupancy affects gene expression, we analyzed transcriptomes of embryos zygotically compromised for either clamp or zelda and found that transcript levels of many zygotically activated genes are similarly affected. Importantly, compromising either clamp or zelda disrupted the expression of critical segmentation and sex determination genes bound by CLAMP (and Zelda). Furthermore, clamp knockdown embryos recapitulate other phenotypes observed in Zelda-depleted embryos, including nuclear division defects, centrosome aberrations, and a disorganized actomyosin network. Based on these data, we propose that CLAMP acts in concert with Zelda to regulate early zygotic transcription.
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Affiliation(s)
- Megan M Colonnetta
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Juan E Abrahante
- University of Minnesota Informatics Institute, Minneapolis, MN 55455, USA
| | - Paul Schedl
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Daryl M Gohl
- University of Minnesota Genomics Center, Minneapolis, MN 55455, USA
| | - Girish Deshpande
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
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16
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Kögler AC, Kherdjemil Y, Bender K, Rabinowitz A, Marco-Ferreres R, Furlong EEM. Extremely rapid and reversible optogenetic perturbation of nuclear proteins in living embryos. Dev Cell 2021; 56:2348-2363.e8. [PMID: 34363757 PMCID: PMC8387026 DOI: 10.1016/j.devcel.2021.07.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 04/18/2021] [Accepted: 07/15/2021] [Indexed: 11/27/2022]
Abstract
Many developmental regulators have complex and context-specific roles in different tissues and stages, making the dissection of their function extremely challenging. As regulatory processes often occur within minutes, perturbation methods that match these dynamics are needed. Here, we present the improved light-inducible nuclear export system (iLEXY), an optogenetic loss-of-function approach that triggers translocation of proteins from the nucleus to the cytoplasm. By introducing a series of mutations, we substantially increased LEXY's efficiency and generated variants with different recovery times. iLEXY enables rapid (t1/2 < 30 s), efficient, and reversible nuclear protein depletion in embryos, and is generalizable to proteins of diverse sizes and functions. Applying iLEXY to the Drosophila master regulator Twist, we phenocopy loss-of-function mutants, precisely map the Twist-sensitive embryonic stages, and investigate the effects of timed Twist depletions. Our results demonstrate the power of iLEXY to dissect the function of pleiotropic factors during embryogenesis with unprecedented temporal precision.
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Affiliation(s)
- Anna C Kögler
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg 69117, Germany
| | - Yacine Kherdjemil
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg 69117, Germany
| | - Katharina Bender
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg 69117, Germany
| | - Adam Rabinowitz
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg 69117, Germany
| | - Raquel Marco-Ferreres
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg 69117, Germany
| | - Eileen E M Furlong
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg 69117, Germany.
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17
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Larson ED, Marsh AJ, Harrison MM. Pioneering the developmental frontier. Mol Cell 2021; 81:1640-1650. [PMID: 33689750 PMCID: PMC8052302 DOI: 10.1016/j.molcel.2021.02.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/28/2021] [Accepted: 02/16/2021] [Indexed: 12/16/2022]
Abstract
Coordinated changes in gene expression allow a single fertilized oocyte to develop into a complex multi-cellular organism. These changes in expression are controlled by transcription factors that gain access to discrete cis-regulatory elements in the genome, allowing them to activate gene expression. Although nucleosomes present barriers to transcription factor occupancy, pioneer transcription factors have unique properties that allow them to bind DNA in the context of nucleosomes, define cis-regulatory elements, and facilitate the subsequent binding of additional factors that determine gene expression. In this capacity, pioneer factors act at the top of gene-regulatory networks to control developmental transitions. Developmental context also influences pioneer factor binding and activity. Here we discuss the interplay between pioneer factors and development, their role in driving developmental transitions, and the influence of the cellular environment on pioneer factor binding and activity.
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Affiliation(s)
- Elizabeth D Larson
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Audrey J Marsh
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Melissa M Harrison
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
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18
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Gaskill MM, Gibson TJ, Larson ED, Harrison MM. GAF is essential for zygotic genome activation and chromatin accessibility in the early Drosophila embryo. eLife 2021; 10:e66668. [PMID: 33720012 PMCID: PMC8079149 DOI: 10.7554/elife.66668] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/14/2021] [Indexed: 12/11/2022] Open
Abstract
Following fertilization, the genomes of the germ cells are reprogrammed to form the totipotent embryo. Pioneer transcription factors are essential for remodeling the chromatin and driving the initial wave of zygotic gene expression. In Drosophila melanogaster, the pioneer factor Zelda is essential for development through this dramatic period of reprogramming, known as the maternal-to-zygotic transition (MZT). However, it was unknown whether additional pioneer factors were required for this transition. We identified an additional maternally encoded factor required for development through the MZT, GAGA Factor (GAF). GAF is necessary to activate widespread zygotic transcription and to remodel the chromatin accessibility landscape. We demonstrated that Zelda preferentially controls expression of the earliest transcribed genes, while genes expressed during widespread activation are predominantly dependent on GAF. Thus, progression through the MZT requires coordination of multiple pioneer-like factors, and we propose that as development proceeds control is gradually transferred from Zelda to GAF.
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Affiliation(s)
- Marissa M Gaskill
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Tyler J Gibson
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Elizabeth D Larson
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Melissa M Harrison
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
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19
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Seo J, Koçak DD, Bartelt LC, Williams CA, Barrera A, Gersbach CA, Reddy TE. AP-1 subunits converge promiscuously at enhancers to potentiate transcription. Genome Res 2021; 31:538-550. [PMID: 33674350 PMCID: PMC8015846 DOI: 10.1101/gr.267898.120] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 02/17/2021] [Indexed: 12/12/2022]
Abstract
The AP-1 transcription factor (TF) dimer contributes to many biological processes and environmental responses. AP-1 can be composed of many interchangeable subunits. Unambiguously determining the binding locations of these subunits in the human genome is challenging because of variable antibody specificity and affinity. Here, we definitively establish the genome-wide binding patterns of five AP-1 subunits by using CRISPR to introduce a common antibody tag on each subunit. We find limited evidence for strong dimerization preferences between subunits at steady state and find that, under a stimulus, dimerization patterns reflect changes in the transcriptome. Further, our analysis suggests that canonical AP-1 motifs indiscriminately recruit all AP-1 subunits to genomic sites, which we term AP-1 hotspots. We find that AP-1 hotspots are predictive of cell type–specific gene expression and of genomic responses to glucocorticoid signaling (more so than super-enhancers) and are significantly enriched in disease-associated genetic variants. Together, these results support a model where promiscuous binding of many AP-1 subunits to the same genomic location play a key role in regulating cell type–specific gene expression and environmental responses.
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Affiliation(s)
- Jungkyun Seo
- Department of Biostatistics and Bioinformatics, Division of Integrative Genomics, Duke University Medical Center, Durham, North Carolina 27708, USA.,Computational Biology and Bioinformatics Graduate Program, Duke University, Durham, North Carolina 27708, USA.,Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708, USA.,Center for Advanced Genomic Technologies, Duke University, Durham, North Carolina 27708, USA
| | - D Dewran Koçak
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708, USA.,Center for Advanced Genomic Technologies, Duke University, Durham, North Carolina 27708, USA.,Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Luke C Bartelt
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708, USA.,University Program in Genetics and Genomics, Duke University, Durham, North Carolina 27708, USA
| | - Courtney A Williams
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708, USA.,Center for Advanced Genomic Technologies, Duke University, Durham, North Carolina 27708, USA
| | - Alejandro Barrera
- Department of Biostatistics and Bioinformatics, Division of Integrative Genomics, Duke University Medical Center, Durham, North Carolina 27708, USA.,Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708, USA.,Center for Advanced Genomic Technologies, Duke University, Durham, North Carolina 27708, USA
| | - Charles A Gersbach
- Computational Biology and Bioinformatics Graduate Program, Duke University, Durham, North Carolina 27708, USA.,Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708, USA.,Center for Advanced Genomic Technologies, Duke University, Durham, North Carolina 27708, USA.,Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA.,University Program in Genetics and Genomics, Duke University, Durham, North Carolina 27708, USA.,Department of Surgery, Duke University Medical Center, Durham, North Carolina 27708, USA
| | - Timothy E Reddy
- Department of Biostatistics and Bioinformatics, Division of Integrative Genomics, Duke University Medical Center, Durham, North Carolina 27708, USA.,Computational Biology and Bioinformatics Graduate Program, Duke University, Durham, North Carolina 27708, USA.,Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708, USA.,Center for Advanced Genomic Technologies, Duke University, Durham, North Carolina 27708, USA.,Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA.,University Program in Genetics and Genomics, Duke University, Durham, North Carolina 27708, USA.,Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina 27708, USA
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20
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Brooks MD, Juang CL, Katari MS, Alvarez JM, Pasquino A, Shih HJ, Huang J, Shanks C, Cirrone J, Coruzzi GM. ConnecTF: A platform to integrate transcription factor-gene interactions and validate regulatory networks. PLANT PHYSIOLOGY 2021; 185:49-66. [PMID: 33631799 PMCID: PMC8133578 DOI: 10.1093/plphys/kiaa012] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/27/2020] [Indexed: 05/08/2023]
Abstract
Deciphering gene regulatory networks (GRNs) is both a promise and challenge of systems biology. The promise lies in identifying key transcription factors (TFs) that enable an organism to react to changes in its environment. The challenge lies in validating GRNs that involve hundreds of TFs with hundreds of thousands of interactions with their genome-wide targets experimentally determined by high-throughput sequencing. To address this challenge, we developed ConnecTF, a species-independent, web-based platform that integrates genome-wide studies of TF-target binding, TF-target regulation, and other TF-centric omic datasets and uses these to build and refine validated or inferred GRNs. We demonstrate the functionality of ConnecTF by showing how integration within and across TF-target datasets uncovers biological insights. Case study 1 uses integration of TF-target gene regulation and binding datasets to uncover TF mode-of-action and identify potential TF partners for 14 TFs in abscisic acid signaling. Case study 2 demonstrates how genome-wide TF-target data and automated functions in ConnecTF are used in precision/recall analysis and pruning of an inferred GRN for nitrogen signaling. Case study 3 uses ConnecTF to chart a network path from NLP7, a master TF in nitrogen signaling, to direct secondary TF2s and to its indirect targets in a Network Walking approach. The public version of ConnecTF (https://ConnecTF.org) contains 3,738,278 TF-target interactions for 423 TFs in Arabidopsis, 839,210 TF-target interactions for 139 TFs in maize (Zea mays), and 293,094 TF-target interactions for 26 TFs in rice (Oryza sativa). The database and tools in ConnecTF will advance the exploration of GRNs in plant systems biology applications for model and crop species.
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Affiliation(s)
- Matthew D Brooks
- Center for Genomics and Systems Biology, Department of Biology, New York University, NY, USA
- USDA ARS Global Change and Photosynthesis Research Unit, Urbana, IL, USA
| | - Che-Lun Juang
- Center for Genomics and Systems Biology, Department of Biology, New York University, NY, USA
| | - Manpreet Singh Katari
- Center for Genomics and Systems Biology, Department of Biology, New York University, NY, USA
| | - José M Alvarez
- Center for Genomics and Systems Biology, Department of Biology, New York University, NY, USA
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
- Millennium Institute for Integrative Biology (iBio), Santiago, Chile
| | - Angelo Pasquino
- Center for Genomics and Systems Biology, Department of Biology, New York University, NY, USA
| | - Hung-Jui Shih
- Center for Genomics and Systems Biology, Department of Biology, New York University, NY, USA
| | - Ji Huang
- Center for Genomics and Systems Biology, Department of Biology, New York University, NY, USA
| | - Carly Shanks
- Center for Genomics and Systems Biology, Department of Biology, New York University, NY, USA
| | - Jacopo Cirrone
- Courant Institute for Mathematical Sciences, Department of Computer Science, New York University NY, USA
| | - Gloria M Coruzzi
- Center for Genomics and Systems Biology, Department of Biology, New York University, NY, USA
- Author for communication: (G.C.)
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21
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Bennett H, Troutman TD, Sakai M, Glass CK. Epigenetic Regulation of Kupffer Cell Function in Health and Disease. Front Immunol 2021; 11:609618. [PMID: 33574817 PMCID: PMC7870864 DOI: 10.3389/fimmu.2020.609618] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022] Open
Abstract
Kupffer cells, the resident macrophages of the liver, comprise the largest pool of tissue macrophages in the body. Within the liver sinusoids Kupffer cells perform functions common across many tissue macrophages including response to tissue damage and antigen presentation. They also engage in specialized activities including iron scavenging and the uptake of opsonized particles from the portal blood. Here, we review recent studies of the epigenetic pathways that establish Kupffer cell identity and function. We describe a model by which liver-environment specific signals induce lineage determining transcription factors necessary for differentiation of Kupffer cells from bone-marrow derived monocytes. We conclude by discussing how these lineage determining transcription factors (LDTFs) drive Kupffer cell behavior during both homeostasis and disease, with particular focus on the relevance of Kupffer cell LDTF pathways in the setting of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis.
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Affiliation(s)
- Hunter Bennett
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Ty D Troutman
- Department of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Mashito Sakai
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, United States.,Department of Biochemistry & Molecular Biology, Nippon Medical School, Tokyo, Japan
| | - Christopher K Glass
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, United States.,Department of Medicine, University of California, San Diego, La Jolla, CA, United States
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22
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Hatleberg WL, Hinman VF. Modularity and hierarchy in biological systems: Using gene regulatory networks to understand evolutionary change. Curr Top Dev Biol 2021; 141:39-73. [DOI: 10.1016/bs.ctdb.2020.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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23
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Barske L, Fabian P, Hirschberger C, Jandzik D, Square T, Xu P, Nelson N, Yu HV, Medeiros DM, Gillis JA, Crump JG. Evolution of vertebrate gill covers via shifts in an ancient Pou3f3 enhancer. Proc Natl Acad Sci U S A 2020; 117:24876-24884. [PMID: 32958671 PMCID: PMC7547273 DOI: 10.1073/pnas.2011531117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Whereas the gill chambers of jawless vertebrates open directly into the environment, jawed vertebrates evolved skeletal appendages that drive oxygenated water unidirectionally over the gills. A major anatomical difference between the two jawed vertebrate lineages is the presence of a single large gill cover in bony fishes versus separate covers for each gill chamber in cartilaginous fishes. Here, we find that these divergent patterns correlate with the pharyngeal arch expression of Pou3f3 orthologs. We identify a deeply conserved Pou3f3 arch enhancer present in humans through sharks but undetectable in jawless fish. Minor differences between the bony and cartilaginous fish enhancers account for their restricted versus pan-arch expression patterns. In zebrafish, mutation of Pou3f3 or the conserved enhancer disrupts gill cover formation, whereas ectopic pan-arch Pou3f3b expression generates ectopic skeletal elements resembling the multimeric covers of cartilaginous fishes. Emergence of this Pou3f3 arch enhancer >430 Mya and subsequent modifications may thus have contributed to the acquisition and diversification of gill covers and respiratory strategies during gnathostome evolution.
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Affiliation(s)
- Lindsey Barske
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033;
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Peter Fabian
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| | | | - David Jandzik
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309
- Department of Zoology, Comenius University in Bratislava, 84215 Bratislava, Slovakia
| | - Tyler Square
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Pengfei Xu
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| | - Nellie Nelson
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| | - Haoze Vincent Yu
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| | - Daniel M Medeiros
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309
| | - J Andrew Gillis
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, United Kingdom
- Marine Biological Laboratory, Woods Hole, MA 02543
| | - J Gage Crump
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, W. M. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033;
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24
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Abstract
Key discoveries in Drosophila have shaped our understanding of cellular "enhancers." With a special focus on the fly, this chapter surveys properties of these adaptable cis-regulatory elements, whose actions are critical for the complex spatial/temporal transcriptional regulation of gene expression in metazoa. The powerful combination of genetics, molecular biology, and genomics available in Drosophila has provided an arena in which the developmental role of enhancers can be explored. Enhancers are characterized by diverse low- or high-throughput assays, which are challenging to interpret, as not all of these methods of identifying enhancers produce concordant results. As a model metazoan, the fly offers important advantages to comprehensive analysis of the central functions that enhancers play in gene expression, and their critical role in mediating the production of phenotypes from genotype and environmental inputs. A major challenge moving forward will be obtaining a quantitative understanding of how these cis-regulatory elements operate in development and disease.
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Affiliation(s)
- Stephen Small
- Department of Biology, Developmental Systems Training Program, New York University, 10003 and
| | - David N Arnosti
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
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25
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Koromila T, Gao F, Iwasaki Y, He P, Pachter L, Gergen JP, Stathopoulos A. Odd-paired is a pioneer-like factor that coordinates with Zelda to control gene expression in embryos. eLife 2020; 9:e59610. [PMID: 32701060 PMCID: PMC7417190 DOI: 10.7554/elife.59610] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 07/22/2020] [Indexed: 01/29/2023] Open
Abstract
Pioneer factors such as Zelda (Zld) help initiate zygotic transcription in Drosophila early embryos, but whether other factors support this dynamic process is unclear. Odd-paired (Opa), a zinc-finger transcription factor expressed at cellularization, controls the transition of genes from pair-rule to segmental patterns along the anterior-posterior axis. Finding that Opa also regulates expression through enhancer sog_Distal along the dorso-ventral axis, we hypothesized Opa's role is more general. Chromatin-immunoprecipitation (ChIP-seq) confirmed its in vivo binding to sog_Distal but also identified widespread binding throughout the genome, comparable to Zld. Furthermore, chromatin assays (ATAC-seq) demonstrate that Opa, like Zld, influences chromatin accessibility genome-wide at cellularization, suggesting both are pioneer factors with common as well as distinct targets. Lastly, embryos lacking opa exhibit widespread, late patterning defects spanning both axes. Collectively, these data suggest Opa is a general timing factor and likely late-acting pioneer factor that drives a secondary wave of zygotic gene expression.
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Affiliation(s)
- Theodora Koromila
- California Institute of Technology, Division of Biology and Biological EngineeringPasadenaUnited States
| | - Fan Gao
- California Institute of Technology, Division of Biology and Biological EngineeringPasadenaUnited States
| | - Yasuno Iwasaki
- Stony Brook University, Department of Biochemistry and Cell Biology and Center for Developmental GeneticsStony BrookUnited States
| | - Peng He
- California Institute of Technology, Division of Biology and Biological EngineeringPasadenaUnited States
| | - Lior Pachter
- California Institute of Technology, Division of Biology and Biological EngineeringPasadenaUnited States
| | - J Peter Gergen
- Stony Brook University, Department of Biochemistry and Cell Biology and Center for Developmental GeneticsStony BrookUnited States
| | - Angelike Stathopoulos
- California Institute of Technology, Division of Biology and Biological EngineeringPasadenaUnited States
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26
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Keller SH, Jena SG, Yamazaki Y, Lim B. Regulation of spatiotemporal limits of developmental gene expression via enhancer grammar. Proc Natl Acad Sci U S A 2020; 117:15096-15103. [PMID: 32541043 PMCID: PMC7334449 DOI: 10.1073/pnas.1917040117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The regulatory specificity of a gene is determined by the structure of its enhancers, which contain multiple transcription factor binding sites. A unique combination of transcription factor binding sites in an enhancer determines the boundary of target gene expression, and their disruption often leads to developmental defects. Despite extensive characterization of binding motifs in an enhancer, it is still unclear how each binding site contributes to overall transcriptional activity. Using live imaging, quantitative analysis, and mathematical modeling, we measured the contribution of individual binding sites in transcriptional regulation. We show that binding site arrangement within the Rho-GTPase component t48 enhancer mediates the expression boundary by mainly regulating the timing of transcriptional activation along the dorsoventral axis of Drosophila embryos. By tuning the binding affinity of the Dorsal (Dl) and Zelda (Zld) sites, we show that single site modulations are sufficient to induce significant changes in transcription. Yet, no one site seems to have a dominant role; rather, multiple sites synergistically drive increases in transcriptional activity. Interestingly, Dl and Zld demonstrate distinct roles in transcriptional regulation. Dl site modulations change spatial boundaries of t48, mostly by affecting the timing of activation and bursting frequency rather than transcriptional amplitude or bursting duration. However, modulating the binding site for the pioneer factor Zld affects both the timing of activation and amplitude, suggesting that Zld may potentiate higher Dl recruitment to target DNAs. We propose that such fine-tuning of dynamic gene control via enhancer structure may play an important role in ensuring normal development.
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Affiliation(s)
- Samuel H Keller
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104
| | - Siddhartha G Jena
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Yuji Yamazaki
- Yutaka Seino Distinguished Center for Diabetes Research, Kansai Electric Power Medical Research Institute, Kobe 650-0047, Japan
| | - Bomyi Lim
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104;
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27
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Wu E, Vastenhouw NL. From mother to embryo: A molecular perspective on zygotic genome activation. Curr Top Dev Biol 2020; 140:209-254. [PMID: 32591075 DOI: 10.1016/bs.ctdb.2020.02.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In animals, the early embryo is mostly transcriptionally silent and development is fueled by maternally supplied mRNAs and proteins. These maternal products are important not only for survival, but also to gear up the zygote's genome for activation. Over the last three decades, research with different model organisms and experimental approaches has identified molecular factors and proposed mechanisms for how the embryo transitions from being transcriptionally silent to transcriptionally competent. In this chapter, we discuss the molecular players that shape the molecular landscape of ZGA and provide insights into their mode of action in activating the transcription program in the developing embryo.
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Affiliation(s)
- Edlyn Wu
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Nadine L Vastenhouw
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
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28
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Castellanos M, Mothi N, Muñoz V. Eukaryotic transcription factors can track and control their target genes using DNA antennas. Nat Commun 2020; 11:540. [PMID: 31992709 PMCID: PMC6987225 DOI: 10.1038/s41467-019-14217-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 12/12/2019] [Indexed: 12/27/2022] Open
Abstract
Eukaryotic transcription factors (TF) function by binding to short 6-10 bp DNA recognition sites located near their target genes, which are scattered through vast genomes. Such process surmounts enormous specificity, efficiency and celerity challenges using a molecular mechanism that remains poorly understood. Combining biophysical experiments, theory and bioinformatics, we dissect the interplay between the DNA-binding domain of Engrailed, a Drosophila TF, and the regulatory regions of its target genes. We find that Engrailed binding affinity is strongly amplified by the DNA regions flanking the recognition site, which contain long tracts of degenerate recognition-site repeats. Such DNA organization operates as an antenna that attracts TF molecules in a promiscuous exchange among myriads of intermediate affinity binding sites. The antenna ensures a local TF supply, enables gene tracking and fine control of the target site's basal occupancy. This mechanism illuminates puzzling gene expression data and suggests novel engineering strategies to control gene expression.
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Affiliation(s)
- Milagros Castellanos
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia), Faraday 9, Campus de Cantoblanco, Madrid, 28049, Spain.,Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Darwin 3, Campus de Cantoblanco, Madrid, 28049, Spain
| | - Nivin Mothi
- Department of Bioengineering, School of Engineering, University of California, 95343, Merced, CA, USA
| | - Victor Muñoz
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia), Faraday 9, Campus de Cantoblanco, Madrid, 28049, Spain. .,Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Darwin 3, Campus de Cantoblanco, Madrid, 28049, Spain. .,Department of Bioengineering, School of Engineering, University of California, 95343, Merced, CA, USA.
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29
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Peng PC, Khoueiry P, Girardot C, Reddington JP, Garfield DA, Furlong EEM, Sinha S. The Role of Chromatin Accessibility in cis-Regulatory Evolution. Genome Biol Evol 2020; 11:1813-1828. [PMID: 31114856 PMCID: PMC6601868 DOI: 10.1093/gbe/evz103] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2019] [Indexed: 02/07/2023] Open
Abstract
Transcription factor (TF) binding is determined by sequence as well as chromatin accessibility. Although the role of accessibility in shaping TF-binding landscapes is well recorded, its role in evolutionary divergence of TF binding, which in turn can alter cis-regulatory activities, is not well understood. In this work, we studied the evolution of genome-wide binding landscapes of five major TFs in the core network of mesoderm specification, between Drosophila melanogaster and Drosophila virilis, and examined its relationship to accessibility and sequence-level changes. We generated chromatin accessibility data from three important stages of embryogenesis in both Drosophila melanogaster and Drosophila virilis and recorded conservation and divergence patterns. We then used multivariable models to correlate accessibility and sequence changes to TF-binding divergence. We found that accessibility changes can in some cases, for example, for the master regulator Twist and for earlier developmental stages, more accurately predict binding change than is possible using TF-binding motif changes between orthologous enhancers. Accessibility changes also explain a significant portion of the codivergence of TF pairs. We noted that accessibility and motif changes offer complementary views of the evolution of TF binding and developed a combined model that captures the evolutionary data much more accurately than either view alone. Finally, we trained machine learning models to predict enhancer activity from TF binding and used these functional models to argue that motif and accessibility-based predictors of TF-binding change can substitute for experimentally measured binding change, for the purpose of predicting evolutionary changes in enhancer activity.
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Affiliation(s)
- Pei-Chen Peng
- Department of Computer Science, University of Illinois at Urbana-Champaign.,Center for Bioinformatics and Functional Genomics, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Pierre Khoueiry
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany.,American University of Beirut (AUB), Department of Biochemistry and Molecular Genetics, Beirut, Lebanon
| | - Charles Girardot
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - James P Reddington
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - David A Garfield
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany.,IRI-Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany
| | - Eileen E M Furlong
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Saurabh Sinha
- Department of Computer Science, University of Illinois at Urbana-Champaign.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
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30
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McDaniel SL, Gibson TJ, Schulz KN, Fernandez Garcia M, Nevil M, Jain SU, Lewis PW, Zaret KS, Harrison MM. Continued Activity of the Pioneer Factor Zelda Is Required to Drive Zygotic Genome Activation. Mol Cell 2019; 74:185-195.e4. [PMID: 30797686 DOI: 10.1016/j.molcel.2019.01.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/10/2018] [Accepted: 01/08/2019] [Indexed: 02/08/2023]
Abstract
Reprogramming cell fate during the first stages of embryogenesis requires that transcriptional activators gain access to the genome and remodel the zygotic transcriptome. Nonetheless, it is not clear whether the continued activity of these pioneering factors is required throughout zygotic genome activation or whether they are only required early to establish cis-regulatory regions. To address this question, we developed an optogenetic strategy to rapidly and reversibly inactivate the master regulator of genome activation in Drosophila, Zelda. Using this strategy, we demonstrate that continued Zelda activity is required throughout genome activation. We show that Zelda binds DNA in the context of nucleosomes and suggest that this allows Zelda to occupy the genome despite the rapid division cycles in the early embryo. These data identify a powerful strategy to inactivate transcription factor function during development and suggest that reprogramming in the embryo may require specific, continuous pioneering functions to activate the genome.
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Affiliation(s)
- Stephen L McDaniel
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison WI 53706, USA
| | - Tyler J Gibson
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison WI 53706, USA
| | - Katharine N Schulz
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison WI 53706, USA
| | - Meilin Fernandez Garcia
- Institute for Regenerative Medicine and Epigenetics Program, Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Markus Nevil
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison WI 53706, USA
| | - Siddhant U Jain
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison WI 53706, USA
| | - Peter W Lewis
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison WI 53706, USA
| | - Kenneth S Zaret
- Institute for Regenerative Medicine and Epigenetics Program, Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Melissa M Harrison
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison WI 53706, USA.
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31
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Kurafeiski JD, Pinto P, Bornberg-Bauer E. Evolutionary Potential of Cis-Regulatory Mutations to Cause Rapid Changes in Transcription Factor Binding. Genome Biol Evol 2019; 11:406-414. [PMID: 30597011 PMCID: PMC6370388 DOI: 10.1093/gbe/evy269] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/11/2018] [Indexed: 01/25/2023] Open
Abstract
Transcriptional regulation is crucial for all biological processes and well investigated at the molecular level for a wide range of organisms. However, it is quite unclear how innovations, such as the activity of a novel regulatory element, evolve. In the case of transcription factor (TF) binding, both a novel TF and a novel-binding site would need to evolve concertedly. Since promiscuous functions have recently been identified as important intermediate steps in creating novel specific functions in many areas such as enzyme evolution and protein-protein interactions, we ask here how promiscuous binding of TFs to TF-binding sites (TFBSs) affects the robustness and evolvability of this tightly regulated system. Specifically, we investigate the binding behavior of several hundred TFs from different species at unprecedented breadth. Our results illustrate multiple aspects of TF-binding interactions, ranging from correlations between the strength of the interaction bond and specificity, to preferences regarding TFBS nucleotide composition in relation to both domains and binding specificity. We identified a subset of high A/T binding motifs. Motifs in this subset had many functionally neutral one-error mutants, and were bound by multiple different binding domains. Our results indicate that, especially for some TF-TFBS associations, low binding specificity confers high degrees of evolvability, that is that few mutations facilitate rapid changes in transcriptional regulation, in particular for large and old TF families. In this study we identify binding motifs exhibiting behavior indicating high evolutionary potential for innovations in transcriptional regulation.
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Affiliation(s)
| | - Paulo Pinto
- Molecular Evolution and Bioinformatics, University of Muenster, Germany
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32
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Hamm DC, Harrison MM. Regulatory principles governing the maternal-to-zygotic transition: insights from Drosophila melanogaster. Open Biol 2018; 8:180183. [PMID: 30977698 PMCID: PMC6303782 DOI: 10.1098/rsob.180183] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/09/2018] [Indexed: 12/19/2022] Open
Abstract
The onset of metazoan development requires that two terminally differentiated germ cells, a sperm and an oocyte, become reprogrammed to the totipotent embryo, which can subsequently give rise to all the cell types of the adult organism. In nearly all animals, maternal gene products regulate the initial events of embryogenesis while the zygotic genome remains transcriptionally silent. Developmental control is then passed from mother to zygote through a process known as the maternal-to-zygotic transition (MZT). The MZT comprises an intimately connected set of molecular events that mediate degradation of maternally deposited mRNAs and transcriptional activation of the zygotic genome. This essential developmental transition is conserved among metazoans but is perhaps best understood in the fruit fly, Drosophila melanogaster. In this article, we will review our understanding of the events that drive the MZT in Drosophila embryos and highlight parallel mechanisms driving this transition in other animals.
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Affiliation(s)
| | - Melissa M. Harrison
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
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33
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Cheng D, Cheng T, Yang X, Zhang Q, Fu J, Feng T, Gong J, Xia Q. The genome-wide transcriptional regulatory landscape of ecdysone in the silkworm. Epigenetics Chromatin 2018; 11:48. [PMID: 30149809 PMCID: PMC6109983 DOI: 10.1186/s13072-018-0216-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 08/10/2018] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND The silkworm, Bombyx mori, a typical representative of metamorphic insects, is of great agricultural and economic importance. The steroid hormone ecdysone (20-hydroxyecdysone, 20E) is the central regulator of insect developmental transitions, and its nuclear receptors are crucial for numerous biological processes, including reproduction, metabolism, and immunity. However, genome-wide DNA regulatory elements and the ecdysone receptor (EcR) that control these programs of gene expression are not well defined. RESULTS In this study, we investigated the alterations in three types of histone modification in silkworm embryonic cells treated with 20E by chromatin immunoprecipitation sequencing (ChIP-seq). We identified enhancers using histone modifications and derived genome-wide ecdysone-dependent enhancer activity maps in the silkworm. We found enhancers enriched for monomethylation of histone H3 Lys4 (H3K4me1) that showed dynamic changes in acetylation of histone H3 Lys27 (H3K27ac) after 20E treatment and functioned to regulate the transcription of specific genes. EcR regulated transcription by binding not only to proximal promoters but also to the distal enhancers of target genes. Moreover, only 52.65% EcR peaks contained ecdysone response element (EcRE) motif, suggesting that EcR regulates the expression of target genes not only by binding directly to EcRE, but also by binding with other transcription factor. CONCLUSIONS Our findings provide novel insights into the complex regulatory landscape of hormone-responsive cell activity and a basis for understanding the complex transcriptional regulatory processes of ecdysone.
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Affiliation(s)
- Dong Cheng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400715, China
| | - Tingcai Cheng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400715, China. .,Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, 2, Tiansheng Road, Beibei, Chongqing, 400715, China.
| | - Xi Yang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400715, China
| | - Quan Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400715, China
| | - Jianfeng Fu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400715, China
| | - Tieshan Feng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400715, China
| | - Jiao Gong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400715, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400715, China.,Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, 2, Tiansheng Road, Beibei, Chongqing, 400715, China
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34
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Guo WL, Huang DS. An efficient method to transcription factor binding sites imputation via simultaneous completion of multiple matrices with positional consistency. MOLECULAR BIOSYSTEMS 2018; 13:1827-1837. [PMID: 28718849 DOI: 10.1039/c7mb00155j] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Transcription factors (TFs) are DNA-binding proteins that have a central role in regulating gene expression. Identification of DNA-binding sites of TFs is a key task in understanding transcriptional regulation, cellular processes and disease. Chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) enables genome-wide identification of in vivo TF binding sites. However, it is still difficult to map every TF in every cell line owing to cost and biological material availability, which poses an enormous obstacle for integrated analysis of gene regulation. To address this problem, we propose a novel computational approach, TFBSImpute, for predicting additional TF binding profiles by leveraging information from available ChIP-seq TF binding data. TFBSImpute fuses the dataset to a 3-mode tensor and imputes missing TF binding signals via simultaneous completion of multiple TF binding matrices with positional consistency. We show that signals predicted by our method achieve overall similarity with experimental data and that TFBSImpute significantly outperforms baseline approaches, by assessing the performance of imputation methods against observed ChIP-seq TF binding profiles. Besides, motif analysis shows that TFBSImpute preforms better in capturing binding motifs enriched in observed data compared with baselines, indicating that the higher performance of TFBSImpute is not simply due to averaging related samples. We anticipate that our approach will constitute a useful complement to experimental mapping of TF binding, which is beneficial for further study of regulation mechanisms and disease.
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Affiliation(s)
- Wei-Li Guo
- Institute of Machine Learning and Systems Biology, School of Electronics and Information Engineering, Tongji University, Shanghai, 201804, China.
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35
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Madsen JGS, Rauch A, Van Hauwaert EL, Schmidt SF, Winnefeld M, Mandrup S. Integrated analysis of motif activity and gene expression changes of transcription factors. Genome Res 2018; 28:243-255. [PMID: 29233921 PMCID: PMC5793788 DOI: 10.1101/gr.227231.117] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 12/01/2017] [Indexed: 01/01/2023]
Abstract
The ability to predict transcription factors based on sequence information in regulatory elements is a key step in systems-level investigation of transcriptional regulation. Here, we have developed a novel tool, IMAGE, for precise prediction of causal transcription factors based on transcriptome profiling and genome-wide maps of enhancer activity. High precision is obtained by combining a near-complete database of position weight matrices (PWMs), generated by compiling public databases and systematic prediction of PWMs for uncharacterized transcription factors, with a state-of-the-art method for PWM scoring and a novel machine learning strategy, based on both enhancers and promoters, to predict the contribution of motifs to transcriptional activity. We applied IMAGE to published data obtained during 3T3-L1 adipocyte differentiation and showed that IMAGE predicts causal transcriptional regulators of this process with higher confidence than existing methods. Furthermore, we generated genome-wide maps of enhancer activity and transcripts during human mesenchymal stem cell commitment and adipocyte differentiation and used IMAGE to identify positive and negative transcriptional regulators of this process. Collectively, our results demonstrate that IMAGE is a powerful and precise method for prediction of regulators of gene expression.
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Affiliation(s)
- Jesper Grud Skat Madsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense, Denmark
| | - Alexander Rauch
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense, Denmark
| | - Elvira Laila Van Hauwaert
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense, Denmark
| | - Søren Fisker Schmidt
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense, Denmark
| | - Marc Winnefeld
- Research and Development, Beiersdorf AG, 20245 Hamburg, Germany
| | - Susanne Mandrup
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense, Denmark
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36
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Chaudhari HG, Cohen BA. Local sequence features that influence AP-1 cis-regulatory activity. Genome Res 2018; 28:171-181. [PMID: 29305491 PMCID: PMC5793781 DOI: 10.1101/gr.226530.117] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 12/22/2017] [Indexed: 01/05/2023]
Abstract
In the genome, most occurrences of transcription factor binding sites (TFBS) have no cis-regulatory activity, which suggests that flanking sequences contain information that distinguishes functional from nonfunctional TFBS. We interrogated the role of flanking sequences near Activator Protein 1 (AP-1) binding sites that reside in DNase I Hypersensitive Sites (DHS) and regions annotated as Enhancers. In these regions, we found that sequence features directly adjacent to the core motif distinguish high from low activity AP-1 sites. Some nearby features are motifs for other TFs that genetically interact with the AP-1 site. Other features are extensions of the AP-1 core motif, which cause the extended sites to match motifs of multiple AP-1 binding proteins. Computational models trained on these data distinguish between sequences with high and low activity AP-1 sites and also predict changes in cis-regulatory activity due to mutations in AP-1 core sites and their flanking sequences. Our results suggest that extended AP-1 binding sites, together with adjacent binding sites for additional TFs, encode part of the information that governs TFBS activity in the genome.
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Affiliation(s)
- Hemangi G Chaudhari
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, Saint Louis, Missouri 63110, USA.,Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri 63110, USA
| | - Barak A Cohen
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, Saint Louis, Missouri 63110, USA.,Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri 63110, USA
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37
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Khoueiry P, Girardot C, Ciglar L, Peng PC, Gustafson EH, Sinha S, Furlong EE. Uncoupling evolutionary changes in DNA sequence, transcription factor occupancy and enhancer activity. eLife 2017; 6. [PMID: 28792889 PMCID: PMC5550276 DOI: 10.7554/elife.28440] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/21/2017] [Indexed: 12/15/2022] Open
Abstract
Sequence variation within enhancers plays a major role in both evolution and disease, yet its functional impact on transcription factor (TF) occupancy and enhancer activity remains poorly understood. Here, we assayed the binding of five essential TFs over multiple stages of embryogenesis in two distant Drosophila species (with 1.4 substitutions per neutral site), identifying thousands of orthologous enhancers with conserved or diverged combinatorial occupancy. We used these binding signatures to dissect two properties of developmental enhancers: (1) potential TF cooperativity, using signatures of co-associations and co-divergence in TF occupancy. This revealed conserved combinatorial binding despite sequence divergence, suggesting protein-protein interactions sustain conserved collective occupancy. (2) Enhancer in-vivo activity, revealing orthologous enhancers with conserved activity despite divergence in TF occupancy. Taken together, we identify enhancers with diverged motifs yet conserved occupancy and others with diverged occupancy yet conserved activity, emphasising the need to functionally measure the effect of divergence on enhancer activity.
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Affiliation(s)
- Pierre Khoueiry
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Charles Girardot
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Lucia Ciglar
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Pei-Chen Peng
- Carl R. Woese Institute of Genomic Biology, University of Illinois, Champaign, United States
| | - E Hilary Gustafson
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Saurabh Sinha
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany.,Carl R. Woese Institute of Genomic Biology, University of Illinois, Champaign, United States
| | - Eileen Em Furlong
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
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38
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Liu S, Zibetti C, Wan J, Wang G, Blackshaw S, Qian J. Assessing the model transferability for prediction of transcription factor binding sites based on chromatin accessibility. BMC Bioinformatics 2017; 18:355. [PMID: 28750606 PMCID: PMC5530957 DOI: 10.1186/s12859-017-1769-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/19/2017] [Indexed: 12/04/2022] Open
Abstract
Background Computational prediction of transcription factor (TF) binding sites in different cell types is challenging. Recent technology development allows us to determine the genome-wide chromatin accessibility in various cellular and developmental contexts. The chromatin accessibility profiles provide useful information in prediction of TF binding events in various physiological conditions. Furthermore, ChIP-Seq analysis was used to determine genome-wide binding sites for a range of different TFs in multiple cell types. Integration of these two types of genomic information can improve the prediction of TF binding events. Results We assessed to what extent a model built upon on other TFs and/or other cell types could be used to predict the binding sites of TFs of interest. A random forest model was built using a set of cell type-independent features such as specific sequences recognized by the TFs and evolutionary conservation, as well as cell type-specific features derived from chromatin accessibility data. Our analysis suggested that the models learned from other TFs and/or cell lines performed almost as well as the model learned from the target TF in the cell type of interest. Interestingly, models based on multiple TFs performed better than single-TF models. Finally, we proposed a universal model, BPAC, which was generated using ChIP-Seq data from multiple TFs in various cell types. Conclusion Integrating chromatin accessibility information with sequence information improves prediction of TF binding.The prediction of TF binding is transferable across TFs and/or cell lines suggesting there are a set of universal “rules”. A computational tool was developed to predict TF binding sites based on the universal “rules”. Electronic supplementary material The online version of this article (doi:10.1186/s12859-017-1769-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sheng Liu
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, 21287, MD, USA
| | - Cristina Zibetti
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, 21287, MD, USA
| | - Jun Wan
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, 21287, MD, USA
| | - Guohua Wang
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, 21287, MD, USA
| | - Seth Blackshaw
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, 21287, MD, USA.,Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, 21287, MD, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, 21287, MD, USA.,Centre for Human Systems Biology, Johns Hopkins University School of Medicine, Baltimore, 21287, MD, USA.,Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, 21287, MD, USA
| | - Jiang Qian
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, 21287, MD, USA.
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Colbran LL, Chen L, Capra JA. Short DNA sequence patterns accurately identify broadly active human enhancers. BMC Genomics 2017; 18:536. [PMID: 28716036 PMCID: PMC5512948 DOI: 10.1186/s12864-017-3934-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 07/09/2017] [Indexed: 12/25/2022] Open
Abstract
Background Enhancers are DNA regulatory elements that influence gene expression. There is substantial diversity in enhancers’ activity patterns: some enhancers drive expression in a single cellular context, while others are active across many. Sequence characteristics, such as transcription factor (TF) binding motifs, influence the activity patterns of regulatory sequences; however, the regulatory logic through which specific sequences drive enhancer activity patterns is poorly understood. Recent analysis of Drosophila enhancers suggested that short dinucleotide repeat motifs (DRMs) are general enhancer sequence features that drive broad regulatory activity. However, it is not known whether the regulatory role of DRMs is conserved across species. Results We performed a comprehensive analysis of the relationship between short DNA sequence patterns, including DRMs, and human enhancer activity in 38,538 enhancers across 411 different contexts. In a machine-learning framework, the occurrence patterns of short sequence motifs accurately predicted broadly active human enhancers. However, DRMs alone were weakly predictive of broad enhancer activity in humans and showed different enrichment patterns than in Drosophila. In general, GC-rich sequence motifs were significantly associated with broad enhancer activity, and consistent with this enrichment, broadly active human TFs recognize GC-rich motifs. Conclusions Our results reveal the importance of specific sequence motifs in broadly active human enhancers, demonstrate the lack of evolutionary conservation of the role of DRMs, and provide a computational framework for investigating the logic of enhancer sequences. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3934-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Laura L Colbran
- Vanderbilt Genetics Institute, Vanderbilt University, Nashville, TN, 37235, USA
| | - Ling Chen
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, 37235, USA
| | - John A Capra
- Vanderbilt Genetics Institute, Vanderbilt University, Nashville, TN, 37235, USA. .,Department of Biological Sciences, Vanderbilt University, Nashville, TN, 37235, USA. .,Center for Structural Biology, Departments of Biomedical Informatics and Computer Science, Vanderbilt University, Nashville, TN, 37235, USA.
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Kreft Ł, Soete A, Hulpiau P, Botzki A, Saeys Y, De Bleser P. ConTra v3: a tool to identify transcription factor binding sites across species, update 2017. Nucleic Acids Res 2017; 45:W490-W494. [PMID: 28472390 PMCID: PMC5570180 DOI: 10.1093/nar/gkx376] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 04/14/2017] [Accepted: 04/25/2017] [Indexed: 12/19/2022] Open
Abstract
Transcription factors are important gene regulators with distinctive roles in development, cell signaling and cell cycling, and they have been associated with many diseases. The ConTra v3 web server allows easy visualization and exploration of predicted transcription factor binding sites (TFBSs) in any genomic region surrounding coding or non-coding genes. In this updated version, with a completely re-implemented user interface using latest web technologies, users can choose from nine reference organisms ranging from human to yeast. ConTra v3 can analyze promoter regions, 5΄-UTRs, 3΄-UTRs and introns or any other genomic region of interest. Thousands of position weight matrices are available to choose from for detecting specific binding sites. Besides this visualization option, additional new exploration functionality is added to the tool that will automatically detect TFBSs having at the same time the highest regulatory potential, the highest conservation scores of the genomic regions covered by the predicted TFBSs and strongest co-localizations with genomic regions exhibiting regulatory activity. The ConTra v3 web server is freely available at http://bioit2.irc.ugent.be/contra/v3.
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Affiliation(s)
- Łukasz Kreft
- VIB Bioinformatics Core, Rijvischestraat 126 3R, 9052 Zwijnaarde-Ghent, Belgium
| | - Arne Soete
- VIB-UGent Center for Inflammation Research, Technologiepark 927, 9052 Zwijnaarde-Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, 9052 Zwijnaarde-Ghent, Belgium
| | - Paco Hulpiau
- VIB-UGent Center for Inflammation Research, Technologiepark 927, 9052 Zwijnaarde-Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, 9052 Zwijnaarde-Ghent, Belgium
| | - Alexander Botzki
- VIB Bioinformatics Core, Rijvischestraat 126 3R, 9052 Zwijnaarde-Ghent, Belgium
| | - Yvan Saeys
- VIB-UGent Center for Inflammation Research, Technologiepark 927, 9052 Zwijnaarde-Ghent, Belgium
- Department of Applied Mathematics, Computer Science and Statistics, Ghent University, Krijgslaan 281, S9, 9000 Gent, Belgium
| | - Pieter De Bleser
- VIB-UGent Center for Inflammation Research, Technologiepark 927, 9052 Zwijnaarde-Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, 9052 Zwijnaarde-Ghent, Belgium
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Costa A, Powell LM, Lowell S, Jarman AP. Atoh1 in sensory hair cell development: constraints and cofactors. Semin Cell Dev Biol 2017; 65:60-68. [DOI: 10.1016/j.semcdb.2016.10.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 09/26/2016] [Accepted: 10/13/2016] [Indexed: 11/28/2022]
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Abstract
The leap from simple unicellularity to complex multicellularity remains one of life's major enigmas. The origins of metazoan developmental gene regulatory mechanisms are sought by analyzing gene regulation in extant eumetazoans, sponges, and unicellular organisms. The main hypothesis of this manuscript is that, developmental enhancers evolved from unicellular inducible promoters that diversified the expression of regulatory genes during metazoan evolution. Promoters and enhancers are functionally similar; both can regulate the transcription of distal promoters and both direct local transcription. Additionally, enhancers have experimentally characterized structural features that reveal their origin from inducible promoters. The distal co-operative regulation among promoters identified in unicellular opisthokonts possibly represents the precursor of distal regulation of promoters by enhancers. During metazoan evolution, constitutive-type promoters of regulatory genes would have acquired novel receptivity to distal regulatory inputs from promoters of inducible genes that eventually specialized as enhancers. The novel regulatory interactions would have caused constitutively expressed genes controlling differential gene expression in unicellular organisms to become themselves differentially expressed. The consequence of the novel regulatory interactions was that regulatory pathways of unicellular organisms became interlaced and ultimately evolved into the intricate developmental gene regulatory networks (GRNs) of extant metazoans.
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Affiliation(s)
- César Arenas-Mena
- Department of Biology, College of Staten Island and Graduate Center, The City University of New York (CUNY), Staten Island, NY 10314, USA
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43
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Reiter F, Wienerroither S, Stark A. Combinatorial function of transcription factors and cofactors. Curr Opin Genet Dev 2017; 43:73-81. [PMID: 28110180 DOI: 10.1016/j.gde.2016.12.007] [Citation(s) in RCA: 190] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 12/14/2016] [Accepted: 12/21/2016] [Indexed: 12/31/2022]
Abstract
Differential gene expression gives rise to the many cell types of complex organisms. Enhancers regulate transcription by binding transcription factors (TFs), which in turn recruit cofactors to activate RNA Polymerase II at core promoters. Transcriptional regulation is typically mediated by distinct combinations of TFs, enabling a relatively small number of TFs to generate a large diversity of cell types. However, how TFs achieve combinatorial enhancer control and how enhancers, enhancer-bound TFs, and the cofactors they recruit regulate RNA Polymerase II activity is not entirely clear. Here, we review how TF synergy is mediated at the level of DNA binding and after binding, the role of cofactors and the post-translational modifications they catalyze, and discuss different models of enhancer-core-promoter communication.
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Affiliation(s)
- Franziska Reiter
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Sebastian Wienerroither
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Alexander Stark
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria.
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Stable Binding of the Conserved Transcription Factor Grainy Head to its Target Genes Throughout Drosophila melanogaster Development. Genetics 2016; 205:605-620. [PMID: 28007888 DOI: 10.1534/genetics.116.195685] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/12/2016] [Indexed: 01/01/2023] Open
Abstract
It has been suggested that transcription factor binding is temporally dynamic, and that changes in binding determine transcriptional output. Nonetheless, this model is based on relatively few examples in which transcription factor binding has been assayed at multiple developmental stages. The essential transcription factor Grainy head (Grh) is conserved from fungi to humans, and controls epithelial development and barrier formation in numerous tissues. Drosophila melanogaster, which possess a single grainy head (grh) gene, provide an excellent system to study this conserved factor. To determine whether temporally distinct binding events allow Grh to control cell fate specification in different tissue types, we used a combination of ChIP-seq and RNA-seq to elucidate the gene regulatory network controlled by Grh during four stages of embryonic development (spanning stages 5-17) and in larval tissue. Contrary to expectations, we discovered that Grh remains bound to at least 1146 genomic loci over days of development. In contrast to this stable DNA occupancy, the subset of genes whose expression is regulated by Grh varies. Grh transitions from functioning primarily as a transcriptional repressor early in development to functioning predominantly as an activator later. Our data reveal that Grh binds to target genes well before the Grh-dependent transcriptional program commences, suggesting it sets the stage for subsequent recruitment of additional factors that execute stage-specific Grh functions.
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45
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EP-DNN: A Deep Neural Network-Based Global Enhancer Prediction Algorithm. Sci Rep 2016; 6:38433. [PMID: 27929098 PMCID: PMC5144062 DOI: 10.1038/srep38433] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 11/08/2016] [Indexed: 01/08/2023] Open
Abstract
We present EP-DNN, a protocol for predicting enhancers based on chromatin features, in different cell types. Specifically, we use a deep neural network (DNN)-based architecture to extract enhancer signatures in a representative human embryonic stem cell type (H1) and a differentiated lung cell type (IMR90). We train EP-DNN using p300 binding sites, as enhancers, and TSS and random non-DHS sites, as non-enhancers. We perform same-cell and cross-cell predictions to quantify the validation rate and compare against two state-of-the-art methods, DEEP-ENCODE and RFECS. We find that EP-DNN has superior accuracy with a validation rate of 91.6%, relative to 85.3% for DEEP-ENCODE and 85.5% for RFECS, for a given number of enhancer predictions and also scales better for a larger number of enhancer predictions. Moreover, our H1 → IMR90 predictions turn out to be more accurate than IMR90 → IMR90, potentially because H1 exhibits a richer signature set and our EP-DNN model is expressive enough to extract these subtleties. Our work shows how to leverage the full expressivity of deep learning models, using multiple hidden layers, while avoiding overfitting on the training data. We also lay the foundation for exploration of cross-cell enhancer predictions, potentially reducing the need for expensive experimentation.
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Koenecke N, Johnston J, He Q, Meier S, Zeitlinger J. Drosophila poised enhancers are generated during tissue patterning with the help of repression. Genome Res 2016; 27:64-74. [PMID: 27979994 PMCID: PMC5204345 DOI: 10.1101/gr.209486.116] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 11/08/2016] [Indexed: 12/18/2022]
Abstract
Histone modifications are frequently used as markers for enhancer states, but how to interpret enhancer states in the context of embryonic development is not clear. The poised enhancer signature, involving H3K4me1 and low levels of H3K27ac, has been reported to mark inactive enhancers that are poised for future activation. However, future activation is not always observed, and alternative reasons for the widespread occurrence of this enhancer signature have not been investigated. By analyzing enhancers during dorsal-ventral (DV) axis formation in the Drosophila embryo, we find that the poised enhancer signature is specifically generated during patterning in the tissue where the enhancers are not induced, including at enhancers that are known to be repressed by a transcriptional repressor. These results suggest that, rather than serving exclusively as an intermediate step before future activation, the poised enhancer state may be a mark for spatial regulation during tissue patterning. We discuss the possibility that the poised enhancer state is more generally the result of repression by transcriptional repressors.
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Affiliation(s)
- Nina Koenecke
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Jeff Johnston
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Qiye He
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Samuel Meier
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Julia Zeitlinger
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.,University of Kansas Medical Center, Department of Pathology, Kansas City, Kansas 66160, USA
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Gahlaut V, Jaiswal V, Kumar A, Gupta PK. Transcription factors involved in drought tolerance and their possible role in developing drought tolerant cultivars with emphasis on wheat (Triticum aestivum L.). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2016; 129:2019-2042. [PMID: 27738714 DOI: 10.1007/s00122-016-2794-z] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 09/15/2016] [Indexed: 05/26/2023]
Abstract
TFs involved in drought tolerance in plants may be utilized in future for developing drought tolerant cultivars of wheat and some other crops. Plants have developed a fairly complex stress response system to deal with drought and other abiotic stresses. These response systems often make use of transcription factors (TFs); a gene encoding a specific TF together with -its target genes constitute a regulon, and take part in signal transduction to activate/silence genes involved in response to drought. Since, five specific families of TFs (out of >80 known families of TFs) have gained widespread attention on account of their significant role in drought tolerance in plants, TFs and regulons belonging to these five multi-gene families (AP2/EREBP, bZIP, MYB/MYC, NAC and WRKY) have been described and their role in improving drought tolerance discussed in this brief review. These TFs often undergo reversible phosphorylation to perform their function, and are also involved in complex networks. Therefore, some details about reversible phosphorylation of TFs by different protein kinases/phosphatases and the co-regulatory networks, which involve either only TFs or TFs with miRNAs, have also been discussed. Literature on transgenics involving genes encoding TFs and that on QTLs and markers associated with TF genes involved in drought tolerance has also been reviewed. Throughout the review, there is a major emphasis on wheat as an important crop, although examples from the model cereal rice (sometimes maize also), and the model plant Arabidopsis have also been used. This knowledge base may eventually allow the use of TF genes for development of drought tolerant cultivars, particularly in wheat.
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Affiliation(s)
- Vijay Gahlaut
- Department of Genetics and Plant Breeding, Ch. Charan Singh University, Meerut, India
| | - Vandana Jaiswal
- Department of Genetics and Plant Breeding, Ch. Charan Singh University, Meerut, India
- Plant Molecular Biology and Genetic Engineering, CSIR-National Botanical Research Institute, Lucknow, India
| | - Anuj Kumar
- Department of Genetics and Plant Breeding, Ch. Charan Singh University, Meerut, India
- Advance Centre for Computational and Applied Biotechnology, Uttarakhand Council for Biotechnology, Dehradun, India
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Yoshida T, Delafontaine P. An Intronic Enhancer Element Regulates Angiotensin II Type 2 Receptor Expression during Satellite Cell Differentiation, and Its Activity Is Suppressed in Congestive Heart Failure. J Biol Chem 2016; 291:25578-25590. [PMID: 27756842 DOI: 10.1074/jbc.m116.752501] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 10/17/2016] [Indexed: 12/20/2022] Open
Abstract
Patients with advanced congestive heart failure (CHF) or chronic kidney disease often have increased angiotensin II (Ang II) levels and cachexia. We previously demonstrated that Ang II, via its type 1 receptor, causes muscle protein breakdown and apoptosis and inhibits satellite cell (SC) proliferation and muscle regeneration, likely contributing to cachexia in CHF and chronic kidney disease. In contrast, Ang II, via its type 2 receptor (AT2R) expression, is robustly induced during SC differentiation, and it potentiates muscle regeneration. To understand the mechanisms regulating AT2R expression and its potential role in muscle regeneration in chronic diseases, we used a mouse model of CHF and found that muscle regeneration was markedly reduced and that this was accompanied by blunted increase of AT2R expression. We performed AT2R promoter reporter analysis during satellite cell differentiation and found that the 70 bp upstream of the AT2R transcription start site contain a core promoter region, and regions upstream of 70 bp to 3 kbp are dispensable for AT2R induction. Instead, AT2R intron 2 acts as a transcriptional enhancer during SC differentiation. Further deletion/mutation analysis revealed that multiple transcription factor binding sites in the +286/+690 region within intron 2 coordinately regulate AT2R transcription. Importantly, +286/+690 enhancer activity was suppressed in CHF mouse skeletal muscle, suggesting that AT2R expression is suppressed in CHF via inhibition of AT2R intronic enhancer activity, leading to lowered muscle regeneration. Thus targeting intron 2 enhancer element could lead to the development of a novel intervention to increase AT2R expression in SCs and potentiate skeletal muscle regenerative capacity in chronic diseases.
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Affiliation(s)
- Tadashi Yoshida
- From the Department of Medicine and Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri 65212
| | - Patrice Delafontaine
- From the Department of Medicine and Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri 65212
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49
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Shlyueva D, Meireles-Filho ACA, Pagani M, Stark A. Genome-Wide Ultrabithorax Binding Analysis Reveals Highly Targeted Genomic Loci at Developmental Regulators and a Potential Connection to Polycomb-Mediated Regulation. PLoS One 2016; 11:e0161997. [PMID: 27575958 PMCID: PMC5004984 DOI: 10.1371/journal.pone.0161997] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 08/16/2016] [Indexed: 12/22/2022] Open
Abstract
Hox homeodomain transcription factors are key regulators of animal development. They specify the identity of segments along the anterior-posterior body axis in metazoans by controlling the expression of diverse downstream targets, including transcription factors and signaling pathway components. The Drosophila melanogaster Hox factor Ultrabithorax (Ubx) directs the development of thoracic and abdominal segments and appendages, and loss of Ubx function can lead for example to the transformation of third thoracic segment appendages (e.g. halters) into second thoracic segment appendages (e.g. wings), resulting in a characteristic four-wing phenotype. Here we present a Drosophila melanogaster strain with a V5-epitope tagged Ubx allele, which we employed to obtain a high quality genome-wide map of Ubx binding sites using ChIP-seq. We confirm the sensitivity of the V5 ChIP-seq by recovering 7/8 of well-studied Ubx-dependent cis-regulatory regions. Moreover, we show that Ubx binding is predictive of enhancer activity as suggested by comparison with a genome-scale resource of in vivo tested enhancer candidates. We observed densely clustered Ubx binding sites at 12 extended genomic loci that included ANTP-C, BX-C, Polycomb complex genes, and other regulators and the clustered binding sites were frequently active enhancers. Furthermore, Ubx binding was detected at known Polycomb response elements (PREs) and was associated with significant enrichments of Pc and Pho ChIP signals in contrast to binding sites of other developmental TFs. Together, our results show that Ubx targets developmental regulators via strongly clustered binding sites and allow us to hypothesize that regulation by Ubx might involve Polycomb group proteins to maintain specific regulatory states in cooperative or mutually exclusive fashion, an attractive model that combines two groups of proteins with prominent gene regulatory roles during animal development.
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Affiliation(s)
- Daria Shlyueva
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | | | - Michaela Pagani
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Alexander Stark
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
- * E-mail:
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50
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Kim SG, Theera-Ampornpunt N, Fang CH, Harwani M, Grama A, Chaterji S. Opening up the blackbox: an interpretable deep neural network-based classifier for cell-type specific enhancer predictions. BMC SYSTEMS BIOLOGY 2016; 10 Suppl 2:54. [PMID: 27490187 PMCID: PMC4977478 DOI: 10.1186/s12918-016-0302-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Background Gene expression is mediated by specialized cis-regulatory modules (CRMs), the most prominent of which are called enhancers. Early experiments indicated that enhancers located far from the gene promoters are often responsible for mediating gene transcription. Knowing their properties, regulatory activity, and genomic targets is crucial to the functional understanding of cellular events, ranging from cellular homeostasis to differentiation. Recent genome-wide investigation of epigenomic marks has indicated that enhancer elements could be enriched for certain epigenomic marks, such as, combinatorial patterns of histone modifications. Methods Our efforts in this paper are motivated by these recent advances in epigenomic profiling methods, which have uncovered enhancer-associated chromatin features in different cell types and organisms. Specifically, in this paper, we use recent state-of-the-art Deep Learning methods and develop a deep neural network (DNN)-based architecture, called EP-DNN, to predict the presence and types of enhancers in the human genome. It uses as features, the expression levels of the histone modifications at the peaks of the functional sites as well as in its adjacent regions. We apply EP-DNN to four different cell types: H1, IMR90, HepG2, and HeLa S3. We train EP-DNN using p300 binding sites as enhancers, and TSS and random non-DHS sites as non-enhancers. We perform EP-DNN predictions to quantify the validation rate for different levels of confidence in the predictions and also perform comparisons against two state-of-the-art computational models for enhancer predictions, DEEP-ENCODE and RFECS. Results We find that EP-DNN has superior accuracy and takes less time to make predictions. Next, we develop methods to make EP-DNN interpretable by computing the importance of each input feature in the classification task. This analysis indicates that the important histone modifications were distinct for different cell types, with some overlaps, e.g., H3K27ac was important in cell type H1 but less so in HeLa S3, while H3K4me1 was relatively important in all four cell types. We finally use the feature importance analysis to reduce the number of input features needed to train the DNN, thus reducing training time, which is often the computational bottleneck in the use of a DNN. Conclusions In this paper, we developed EP-DNN, which has high accuracy of prediction, with validation rates above 90 % for the operational region of enhancer prediction for all four cell lines that we studied, outperforming DEEP-ENCODE and RFECS. Then, we developed a method to analyze a trained DNN and determine which histone modifications are important, and within that, which features proximal or distal to the enhancer site, are important.
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Affiliation(s)
- Seong Gon Kim
- Department of Computer Science, Purdue University, West Lafayette, IN, USA
| | | | - Chih-Hao Fang
- Department of Computer Science, Purdue University, West Lafayette, IN, USA
| | - Mrudul Harwani
- Department of Computer Science, Purdue University, West Lafayette, IN, USA
| | - Ananth Grama
- Department of Computer Science, Purdue University, West Lafayette, IN, USA
| | - Somali Chaterji
- Department of Computer Science, Purdue University, West Lafayette, IN, USA.
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