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Zhou BR, Feng H, Huang F, Zhu I, Portillo-Ledesma S, Shi D, Zaret KS, Schlick T, Landsman D, Wang Q, Bai Y. Structural insights into the cooperative nucleosome recognition and chromatin opening by FOXA1 and GATA4. Mol Cell 2024; 84:3061-3079.e10. [PMID: 39121853 PMCID: PMC11344660 DOI: 10.1016/j.molcel.2024.07.016] [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: 02/12/2024] [Revised: 06/10/2024] [Accepted: 07/16/2024] [Indexed: 08/12/2024]
Abstract
Mouse FOXA1 and GATA4 are prototypes of pioneer factors, initiating liver cell development by binding to the N1 nucleosome in the enhancer of the ALB1 gene. Using cryoelectron microscopy (cryo-EM), we determined the structures of the free N1 nucleosome and its complexes with FOXA1 and GATA4, both individually and in combination. We found that the DNA-binding domains of FOXA1 and GATA4 mainly recognize the linker DNA and an internal site in the nucleosome, respectively, whereas their intrinsically disordered regions interact with the acidic patch on histone H2A-H2B. FOXA1 efficiently enhances GATA4 binding by repositioning the N1 nucleosome. In vivo DNA editing and bioinformatics analyses suggest that the co-binding mode of FOXA1 and GATA4 plays important roles in regulating genes involved in liver cell functions. Our results reveal the mechanism whereby FOXA1 and GATA4 cooperatively bind to the nucleosome through nucleosome repositioning, opening chromatin by bending linker DNA and obstructing nucleosome packing.
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Affiliation(s)
- Bing-Rui Zhou
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Hanqiao Feng
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Furong Huang
- Department of Pathology and Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Iris Zhu
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stephanie Portillo-Ledesma
- Department of Chemistry, New York University, 100 Washington Square East, Silver Building, New York, NY 10003, USA; Simons Center for Computational Physical Chemistry, New York University, 24 Waverly Place, Silver Building, New York, NY 10003, USA
| | - Dan Shi
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Kenneth S Zaret
- Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Cell and Development Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Tamar Schlick
- Department of Chemistry, New York University, 100 Washington Square East, Silver Building, New York, NY 10003, USA; Simons Center for Computational Physical Chemistry, New York University, 24 Waverly Place, Silver Building, New York, NY 10003, USA; Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, NY 10012, USA; New York University-East China Normal University Center for Computational Chemistry, New York University Shanghai, Shanghai 200122, China
| | - David Landsman
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20892, USA
| | - Qianben Wang
- Department of Pathology and Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Yawen Bai
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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2
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Freund MM, Harrison MM, Torres-Zelada EF. Exploring the reciprocity between pioneer factors and development. Development 2024; 151:dev201921. [PMID: 38958075 PMCID: PMC11266817 DOI: 10.1242/dev.201921] [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] [Indexed: 07/04/2024]
Abstract
Development is regulated by coordinated changes in gene expression. Control of these changes in expression is largely governed by the binding of transcription factors to specific regulatory elements. However, the packaging of DNA into chromatin prevents the binding of many transcription factors. Pioneer factors overcome this barrier owing to unique properties that enable them to bind closed chromatin, promote accessibility and, in so doing, mediate binding of additional factors that activate gene expression. Because of these properties, pioneer factors act at the top of gene-regulatory networks and drive developmental transitions. Despite the ability to bind target motifs in closed chromatin, pioneer factors have cell type-specific chromatin occupancy and activity. Thus, developmental context clearly shapes pioneer-factor function. Here, we discuss this reciprocal interplay between pioneer factors and development: how pioneer factors control changes in cell fate and how cellular environment influences pioneer-factor binding and activity.
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Affiliation(s)
- Meghan M. Freund
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 52706, USA
| | - Melissa M. Harrison
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 52706, USA
| | - Eliana F. Torres-Zelada
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 52706, USA
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3
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Orsetti A, van Oosten D, Vasarhelyi RG, Dănescu TM, Huertas J, van Ingen H, Cojocaru V. Structural dynamics in chromatin unraveling by pioneer transcription factors. Biophys Rev 2024; 16:365-382. [PMID: 39099839 PMCID: PMC11297019 DOI: 10.1007/s12551-024-01205-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 06/18/2024] [Indexed: 08/06/2024] Open
Abstract
Pioneer transcription factors are proteins with a dual function. First, they regulate transcription by binding to nucleosome-free DNA regulatory elements. Second, they bind to DNA while wrapped around histone proteins in the chromatin and mediate chromatin opening. The molecular mechanisms that connect the two functions are yet to be discovered. In recent years, pioneer factors received increased attention mainly because of their crucial role in promoting cell fate transitions that could be used for regenerative therapies. For example, the three factors required to induce pluripotency in somatic cells, Oct4, Sox2, and Klf4 were classified as pioneer factors and studied extensively. With this increased attention, several structures of complexes between pioneer factors and chromatin structural units (nucleosomes) have been resolved experimentally. Furthermore, experimental and computational approaches have been designed to study two unresolved, key scientific questions: First, do pioneer factors induce directly local opening of nucleosomes and chromatin fibers upon binding? And second, how do the unstructured tails of the histones impact the structural dynamics involved in such conformational transitions? Here we review the current knowledge about transcription factor-induced nucleosome dynamics and the role of the histone tails in this process. We discuss what is needed to bridge the gap between the static views obtained from the experimental structures and the key structural dynamic events in chromatin opening. Finally, we propose that integrating nuclear magnetic resonance spectroscopy with molecular dynamics simulations is a powerful approach to studying pioneer factor-mediated dynamics of nucleosomes and perhaps small chromatin fibers using native DNA sequences.
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Affiliation(s)
- Andrea Orsetti
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Daphne van Oosten
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | | | - Theodor-Marian Dănescu
- Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Jan Huertas
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, England
| | - Hugo van Ingen
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Vlad Cojocaru
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
- STAR-UBB Institute, Babeş-Bolyai University, Cluj-Napoca, Romania
- Max Planck Institute for Molecular Biomedicine, Münster, Germany
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4
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Stoeber S, Godin H, Xu C, Bai L. Pioneer factors: nature or nurture? Crit Rev Biochem Mol Biol 2024:1-15. [PMID: 38778580 DOI: 10.1080/10409238.2024.2355885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 05/13/2024] [Indexed: 05/25/2024]
Abstract
Chromatin is densely packed with nucleosomes, which limits the accessibility of many chromatin-associated proteins. Pioneer factors (PFs) are usually viewed as a special group of sequence-specific transcription factors (TFs) that can recognize nucleosome-embedded motifs, invade compact chromatin, and generate open chromatin regions. Through this process, PFs initiate a cascade of events that play key roles in gene regulation and cell differentiation. A current debate in the field is if PFs belong to a unique subset of TFs with intrinsic "pioneering activity", or if all TFs have the potential to function as PFs within certain cellular contexts. There are also different views regarding the key feature(s) that define pioneering activity. In this review, we present evidence from the literature related to these alternative views and discuss how to potentially reconcile them. It is possible that both intrinsic properties, like tight nucleosome binding and structural compatibility, and cellular conditions, like concentration and co-factor availability, are important for PF function.
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Affiliation(s)
- Shane Stoeber
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
- Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, PA, USA
| | - Holly Godin
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
- Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, PA, USA
| | - Cheng Xu
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
- Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, PA, USA
| | - Lu Bai
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
- Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, PA, USA
- Department of Physics, The Pennsylvania State University, University Park, PA, USA
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5
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Lian T, Guan R, Zhou BR, Bai Y. Structural mechanism of synergistic targeting of the CX3CR1 nucleosome by PU.1 and C/EBPα. Nat Struct Mol Biol 2024; 31:633-643. [PMID: 38267599 DOI: 10.1038/s41594-023-01189-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 11/23/2023] [Indexed: 01/26/2024]
Abstract
Pioneer transcription factors are vital for cell fate changes. PU.1 and C/EBPα work together to regulate hematopoietic stem cell differentiation. However, how they recognize in vivo nucleosomal DNA targets remains elusive. Here we report the structures of the nucleosome containing the mouse genomic CX3CR1 enhancer DNA and its complexes with PU.1 alone and with both PU.1 and the C/EBPα DNA binding domain. Our structures reveal that PU.1 binds the DNA motif at the exit linker, shifting 17 bp of DNA into the core region through interactions with H2A, unwrapping ~20 bp of nucleosomal DNA. C/EBPα binding, aided by PU.1's repositioning, unwraps ~25 bp of entry DNA. The PU.1 Q218H mutation, linked to acute myeloid leukemia, disrupts PU.1-H2A interactions. PU.1 and C/EBPα jointly displace linker histone H1 and open the H1-condensed nucleosome array. Our study unveils how two pioneer factors can work cooperatively to open closed chromatin by altering DNA positioning in the nucleosome.
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Affiliation(s)
- Tengfei Lian
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Ruifang Guan
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Bing-Rui Zhou
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yawen Bai
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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6
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Barral A, Zaret KS. Pioneer factors: roles and their regulation in development. Trends Genet 2024; 40:134-148. [PMID: 37940484 PMCID: PMC10873006 DOI: 10.1016/j.tig.2023.10.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/06/2023] [Accepted: 10/06/2023] [Indexed: 11/10/2023]
Abstract
Pioneer factors are a subclass of transcription factors that can bind and initiate opening of silent chromatin regions. Pioneer factors subsequently regulate lineage-specific genes and enhancers and, thus, activate the zygotic genome after fertilization, guide cell fate transitions during development, and promote various forms of human cancers. As such, pioneer factors are useful in directed cell reprogramming. In this review, we define the structural and functional characteristics of pioneer factors, how they bind and initiate opening of closed chromatin regions, and the consequences for chromatin dynamics and gene expression during cell differentiation. We also discuss emerging mechanisms that modulate pioneer factors during development.
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Affiliation(s)
- Amandine Barral
- Institute for Regenerative Medicine and Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Boulevard, Philadelphia, PA 19104, USA
| | - Kenneth S Zaret
- Institute for Regenerative Medicine and Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Boulevard, Philadelphia, PA 19104, USA.
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7
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Lian T, Guan R, Zhou BR, Bai Y. Structural mechanism of synergistic targeting of the CX3CR1 nucleosome by PU.1 and C/EBPα. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.25.554718. [PMID: 37790476 PMCID: PMC10542146 DOI: 10.1101/2023.08.25.554718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Pioneer transcription factors are vital for cell fate changes. PU.1 and C/EBPα work together to regulate hematopoietic stem cell differentiation. However, how they recognize in vivo nucleosomal DNA targets remain elusive. Here we report the structures of the nucleosome containing the mouse genomic CX3CR1 enhancer DNA and its complexes with PU.1 alone and with both PU.1 and the C/EBPα DNA binding domain. Our structures reveal that PU.1 binds the DNA motif at the exit linker, shifting 17 bp of DNA into the core region through interactions with H2A, unwrapping ~20 bp of nucleosomal DNA. C/EBPα binding, aided by PU.1's repositioning, unwraps ~25 bp entry DNA. The PU.1 Q218H mutation, linked to acute myeloid leukemia, disrupts PU.1-H2A interactions. PU.1 and C/EBPα jointly displace linker histone H1 and open the H1-condensed nucleosome array. Our study unveils how two pioneer factors can work cooperatively to open closed chromatin by altering DNA positioning in the nucleosome.
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Affiliation(s)
- Tengfei Lian
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
- These authors equally contributed to this work
| | - Ruifang Guan
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
- These authors equally contributed to this work
| | - Bing-Rui Zhou
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yawen Bai
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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8
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Sinha KK, Bilokapic S, Du Y, Malik D, Halic M. Histone modifications regulate pioneer transcription factor cooperativity. Nature 2023; 619:378-384. [PMID: 37225990 PMCID: PMC10338341 DOI: 10.1038/s41586-023-06112-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 04/21/2023] [Indexed: 05/26/2023]
Abstract
Pioneer transcription factors have the ability to access DNA in compacted chromatin1. Multiple transcription factors can bind together to a regulatory element in a cooperative way, and cooperation between the pioneer transcription factors OCT4 (also known as POU5F1) and SOX2 is important for pluripotency and reprogramming2-4. However, the molecular mechanisms by which pioneer transcription factors function and cooperate on chromatin remain unclear. Here we present cryo-electron microscopy structures of human OCT4 bound to a nucleosome containing human LIN28B or nMATN1 DNA sequences, both of which bear multiple binding sites for OCT4. Our structural and biochemistry data reveal that binding of OCT4 induces changes to the nucleosome structure, repositions the nucleosomal DNA and facilitates cooperative binding of additional OCT4 and of SOX2 to their internal binding sites. The flexible activation domain of OCT4 contacts the N-terminal tail of histone H4, altering its conformation and thus promoting chromatin decompaction. Moreover, the DNA-binding domain of OCT4 engages with the N-terminal tail of histone H3, and post-translational modifications at H3K27 modulate DNA positioning and affect transcription factor cooperativity. Thus, our findings suggest that the epigenetic landscape could regulate OCT4 activity to ensure proper cell programming.
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Affiliation(s)
- Kalyan K Sinha
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Silvija Bilokapic
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Yongming Du
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Deepshikha Malik
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Mario Halic
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.
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9
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Guan R, Lian T, Zhou BR, Wheeler D, Bai Y. Structural mechanism of LIN28B nucleosome targeting by OCT4. Mol Cell 2023; 83:1970-1982.e6. [PMID: 37327775 PMCID: PMC10276192 DOI: 10.1016/j.molcel.2023.05.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 03/31/2023] [Accepted: 05/19/2023] [Indexed: 06/18/2023]
Abstract
Pioneer transcription factors are essential for cell fate changes by targeting closed chromatin. OCT4 is a crucial pioneer factor that can induce cell reprogramming. However, the structural basis of how pioneer factors recognize the in vivo nucleosomal DNA targets is unknown. Here, we determine the high-resolution structures of the nucleosome containing human LIN28B DNA and its complexes with the OCT4 DNA binding region. Three OCT4s bind the pre-positioned nucleosome by recognizing non-canonical DNA sequences. Two use their POUS domains while the other uses the POUS-loop-POUHD region; POUHD serves as a wedge to unwrap ∼25 base pair DNA. Our analysis of previous genomic data and determination of the ESRRB-nucleosome-OCT4 structure confirmed the generality of these structural features. Moreover, biochemical studies suggest that multiple OCT4s cooperatively open the H1-condensed nucleosome array containing the LIN28B nucleosome. Thus, our study suggests a mechanism of how OCT4 can target the nucleosome and open closed chromatin.
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Affiliation(s)
- Ruifang Guan
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tengfei Lian
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bing-Rui Zhou
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David Wheeler
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yawen Bai
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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10
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Hashemi Karoii D, Azizi H. OCT4 protein and gene expression analysis in the differentiation of spermatogonia stem cells into neurons by immunohistochemistry, immunocytochemistry, and bioinformatics analysis. Stem Cell Rev Rep 2023:10.1007/s12015-023-10548-8. [PMID: 37119454 DOI: 10.1007/s12015-023-10548-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2023] [Indexed: 05/01/2023]
Abstract
BACKGROUND Spermatogonia Stem Cells (SSCs) are potential candidates for reprogramming and regeneration. Recent studies have revealed that differentiated cells can be reverted to pluripotent by overexpressing a set of pluripotent transcription factors. OCT4 (encoded by pou5f1), a POU transcription factor family member, is essential to the potential that controls pluripotency, and it is widely expressed in pluripotent stem cells, although it decreased or suppressed after differentiation. METHODS In this investigated research, we examined the OCT4 expression during the differentiation of SSCs into neurons (involving four stages in the following order: SSCs in vivo and in-vitro, embryonic Stem Cell-like (ES-like), Embryonic Bodies (EBs), and finally Neurons) by Immunocytochemistry (ICC), Immunohistochemistry (IMH), and Fluidigm Real-Time polymerase chain reaction. In addition, we use some databases like STRING to predict protein-protein interaction and enrichment analysis. RESULTS We evaluated the expression of OCT4 in this process, and we observed that it is expressed in SSCs, ES-like, and EBs during the differentiation of spermatogonia stem cells into adult neurons. We show that by adding RA to EBs, the expression of OCT4 is reduced and is not expressed in the neuron cells. We observed that the expression of OCT4 is linked and interacts with the differentiation of spermatogonia stem cells into neuron cells, and it has been shown to be biologically functional, like stem cell maintenance and somatic cell reprogramming. CONCLUSION Our findings can help us better understand the process of differentiation of spermatogonia stem cells into neurons, and it can be effective in finding new and more efficient treatments for neurogenesis and repair of neurons. We examined the OCT4 expression during the differentiation of SSCs into neurons (involving four stages in the following order: SSCs in vivo and in-vitro, embryonic Stem Cell-like (ES-like), Embryonic Bodies (EBs), and finally Neurons) by Immunocytochemistry (ICC), Immunohistochemistry (IMH), and Fluidigm Real-Time polymerase chain reaction. In addition, we use some databases like STRING to predict protein-protein interaction and enrichment analysis. We evaluated the expression of OCT4 in this process, and we observed that it is expressed in SSCs, ES-like, and EBs during the differentiation of spermatogonia stem cells into adult neurons. We show that by adding RA to EBs, the expression of OCT4 is reduced and is not expressed in the neuron cells. We observed that the expression of OCT4 is linked and interacts with the differentiation of spermatogonia stem cells into neuron cells, and it has been shown to be biologically functional, like stem cell maintenance and somatic cell reprogramming.
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Affiliation(s)
- Danial Hashemi Karoii
- Faculty of Biotechnology, Amol University of Special Modern Technologies, Amol, Iran
- Department of Cell and Molecular Biology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hossein Azizi
- Faculty of Biotechnology, Amol University of Special Modern Technologies, Amol, Iran.
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11
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Sinha K, Bilokapic S, Du Y, Malik D, Halic M. Histone modifications regulate pioneer transcription factor binding and cooperativity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.14.532583. [PMID: 36993452 PMCID: PMC10055048 DOI: 10.1101/2023.03.14.532583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Pioneer transcription factors have the ability to access DNA in compacted chromatin. Multiple transcription factors can bind together to a regulatory element in a cooperative way and cooperation between pioneer transcription factors Oct4 and Sox2 is important for pluripotency and reprogramming. However, the molecular mechanisms by which pioneer transcription factors function and cooperate remain unclear. Here we present cryo-EM structures of human Oct4 bound to a nucleosome containing human Lin28B and nMatn1 DNA sequences, which bear multiple binding sites for Oct4. Our structural and biochemistry data reveal that Oct4 binding induces changes to the nucleosome structure, repositions the nucleosomal DNA and facilitates cooperative binding of additional Oct4 and of Sox2 to their internal binding sites. The flexible activation domain of Oct4 contacts the histone H4 N-terminal tail, altering its conformation and thus promoting chromatin decompaction. Moreover, the DNA binding domain of Oct4 engages with histone H3 N-terminal tail, and posttranslational modifications at H3K27 modulate DNA positioning and affect transcription factor cooperativity. Thus, our data show that the epigenetic landscape can regulate Oct4 activity to ensure proper cell reprogramming.
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Affiliation(s)
- Kalyan Sinha
- Department of Structural Biology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Silvija Bilokapic
- Department of Structural Biology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Yongming Du
- Department of Structural Biology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Deepshikha Malik
- Department of Structural Biology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Mario Halic
- Department of Structural Biology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
- Corresponding author:
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12
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von Eyben FE, Kristiansen K, Kapp DS, Hu R, Preda O, Nogales FF. Epigenetic Regulation of Driver Genes in Testicular Tumorigenesis. Int J Mol Sci 2023; 24:ijms24044148. [PMID: 36835562 PMCID: PMC9966837 DOI: 10.3390/ijms24044148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/15/2023] [Accepted: 02/15/2023] [Indexed: 02/22/2023] Open
Abstract
In testicular germ cell tumor type II (TGCT), a seminoma subtype expresses an induced pluripotent stem cell (iPSC) panel with four upregulated genes, OCT4/POU5F1, SOX17, KLF4, and MYC, and embryonal carcinoma (EC) has four upregulated genes, OCT4/POU5F1, SOX2, LIN28, and NANOG. The EC panel can reprogram cells into iPSC, and both iPSC and EC can differentiate into teratoma. This review summarizes the literature on epigenetic regulation of the genes. Epigenetic mechanisms, such as methylations of cytosines on the DNA string and methylations and acetylations of histone 3 lysines, regulate expression of these driver genes between the TGCT subtypes. In TGCT, the driver genes contribute to well-known clinical characteristics and the driver genes are also important for aggressive subtypes of many other malignancies. In conclusion, epigenetic regulation of the driver genes are important for TGCT and for oncology in general.
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Affiliation(s)
- Finn E. von Eyben
- Center for Tobacco Control Research, Birkevej 17, 5230 Odense, Denmark
- Correspondence: ; Tel.: +45-66145862
| | - Karsten Kristiansen
- Laboratory of Genomics and Molecular Biomedicine, August Krogh Building Department of Biology, University of Copenhagen, Universitetsparken 13, 2100 Copenhagen, Denmark
- BGI-Research, BGI-Shenzhen, Shenzhen 518120, China
- Institute of Metagenomics, Qingdao-Europe Advanced Institute for Life Sciences, BGI-Qingdao, Qingdao 166555, China
| | - Daniel S. Kapp
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Rong Hu
- Department of Pathology, Laboratory Medicine, University of Wisconsin Hospital and Clinics, Madison, WI 53792, USA
| | - Ovidiu Preda
- Department of Pathology, San Cecilio University Hospital, 18071 Granada, CP, Spain
| | - Francisco F. Nogales
- Department of Pathology, School of Medicine, University Granada, 18071 Granada, CP, Spain
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13
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Malaga Gadea FC, Nikolova EN. Structural Plasticity of Pioneer Factor Sox2 and DNA Bendability Modulate Nucleosome Engagement and Sox2-Oct4 Synergism. J Mol Biol 2023; 435:167916. [PMID: 36495920 PMCID: PMC10184184 DOI: 10.1016/j.jmb.2022.167916] [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: 09/01/2022] [Revised: 12/01/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022]
Abstract
Pioneer transcription factors (pTFs) can bind directly to silent chromatin and promote vital transcriptional programs. Here, by integrating high-resolution nuclear magnetic resonance (NMR) spectroscopy with biochemistry, we reveal new structural and mechanistic insights into the interaction of pluripotency pTFs and functional partners Sox2 and Oct4 with nucleosomes. We find that the affinity and conformation of Sox2 for solvent-exposed nucleosome sites depend strongly on their position and DNA sequence. Sox2, which is partially disordered but becomes structured upon DNA binding and bending, forms a super-stable nucleosome complex at superhelical location +5 (SHL+5) with similar affinity and conformation to that with naked DNA. However, at suboptimal internal and end-positioned sites where DNA may be harder to deform, Sox2 favors partially unfolded and more dynamic states that are encoded in its intrinsic flexibility. Importantly, Sox2 structure and DNA bending can be stabilized by synergistic Oct4 binding, but only on adjacent motifs near the nucleosome edge and with the full Oct4 DNA-binding domain. Further mutational studies reveal that strategically impaired Sox2 folding is coupled to reduced DNA bending and inhibits nucleosome binding and Sox2-Oct4 cooperation, while increased nucleosomal DNA flexibility enhances Sox2 association. Together, our findings fit a model where the site-specific DNA bending propensity and structural plasticity of Sox2 govern distinct modes of nucleosome engagement and modulate Sox2-Oct4 synergism. The principles outlined here can potentially guide pTF site selection in the genome and facilitate interaction with other chromatin factors or chromatin opening in vivo.
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Affiliation(s)
- Fabiana C Malaga Gadea
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Evgenia N Nikolova
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA.
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14
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Guan R, Lian T, Zhou BR, Bai Y. Structural mechanism of LIN28B nucleosome targeting by OCT4 for pluripotency. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.03.522631. [PMID: 36789416 PMCID: PMC9928048 DOI: 10.1101/2023.01.03.522631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Pioneer transcription factors are essential for cell fate changes by targeting closed chromatin. OCT4 is a crucial pioneer factor that can induce cell reprogramming. However, the structural basis of how pioneer factors recognize the in vivo nucleosomal DNA targets is unknown. Here, we determine the high-resolution structures of the nucleosome containing human LIN28B DNA and its complexes with the OCT4 DNA binding region. Three OCT4s bind the pre-positioned nucleosome by recognizing non-canonical DNA motifs. Two use their POUS domains by forming extensive hydrogen bonds. The other uses the POUS-loop-POUHD region; POUHD serves as a wedge to unwrap ∼25 base pair DNA. Biochemical studies suggest that multiple OCT4s cooperatively open the H1-condensed nucleosome array containing the LIN28B nucleosome. Our study suggests a mechanism whereby OCT4s target the LIN28B nucleosome by forming multivalent interactions with nucleosomal motifs, unwrapping nucleosomal DNA, evicting H1, and cooperatively open closed chromatin to initiate cell reprogramming.
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Affiliation(s)
- Ruifang Guan
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.,These authors equally contributed to this work
| | - Tengfei Lian
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.,These authors equally contributed to this work
| | - Bing-Rui Zhou
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Yawen Bai
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.,Correspondence:
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15
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Pluta R, Aragón E, Prescott NA, Ruiz L, Mees RA, Baginski B, Flood JR, Martin-Malpartida P, Massagué J, David Y, Macias MJ. Molecular basis for DNA recognition by the maternal pioneer transcription factor FoxH1. Nat Commun 2022; 13:7279. [PMID: 36435807 PMCID: PMC9701222 DOI: 10.1038/s41467-022-34925-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 11/10/2022] [Indexed: 11/28/2022] Open
Abstract
Forkhead box H1 (FoxH1) is an essential maternal pioneer factor during embryonic development that binds to specific GG/GT-containing DNA target sequences. Here we have determined high-resolution structures of three FoxH1 proteins (from human, frog and fish species) and four DNAs to clarify the way in which FoxH1 binds to these sites. We found that the protein-DNA interactions extend to both the minor and major DNA grooves and are thus almost twice as extensive as those of other FOX family members. Moreover, we identified two specific amino acid changes in FoxH1 that allowed the recognition of GG/GT motifs. Consistent with the pioneer factor activity of FoxH1, we found that its affinity for nucleosomal DNA is even higher than for linear DNA fragments. The structures reported herein illustrate how FoxH1 binding to distinct DNA sites provides specificity and avoids cross-regulation by other FOX proteins that also operate during the maternal-zygotic transition and select canonical forkhead sites.
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Affiliation(s)
- Radoslaw Pluta
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, 08028, Spain
| | - Eric Aragón
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, 08028, Spain
| | - Nicholas A Prescott
- Tri-Institutional PhD Program in Chemical Biology, New York, NY, USA
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Lidia Ruiz
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, 08028, Spain
| | - Rebeca A Mees
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, 08028, Spain
| | - Blazej Baginski
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, 08028, Spain
| | - Julia R Flood
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Pau Martin-Malpartida
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, 08028, Spain
| | - Joan Massagué
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Yael David
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, 10065, USA
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Maria J Macias
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, 08028, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, Barcelona, 08010, Spain.
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16
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Takizawa Y, Kurumizaka H. Chromatin structure meets cryo-EM: Dynamic building blocks of the functional architecture. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2022; 1865:194851. [PMID: 35952957 DOI: 10.1016/j.bbagrm.2022.194851] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/04/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
Chromatin is a dynamic molecular complex composed of DNA and proteins that package the DNA in the nucleus of eukaryotic cells. The basic structural unit of chromatin is the nucleosome core particle, composed of ~150 base pairs of genomic DNA wrapped around a histone octamer containing two copies each of four histones, H2A, H2B, H3, and H4. Individual nucleosome core particles are connected by short linker DNAs, forming a nucleosome array known as a beads-on-a-string fiber. Higher-order structures of chromatin are closely linked to nuclear events such as replication, transcription, recombination, and repair. Recently, a variety of chromatin structures have been determined by single-particle cryo-electron microscopy (cryo-EM) and cryo-electron tomography (cryo-ET), and their structural details have provided clues about the chromatin architecture functions in the cell. In this review, we highlight recent cryo-EM structural studies of a fundamental chromatin unit to clarify the functions of chromatin.
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Affiliation(s)
- Yoshimasa Takizawa
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
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17
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MacCarthy CM, Huertas J, Ortmeier C, Vom Bruch H, Tan DS, Reinke D, Sander A, Bergbrede T, Jauch R, Schöler HR, Cojocaru V. OCT4 interprets and enhances nucleosome flexibility. Nucleic Acids Res 2022; 50:10311-10327. [PMID: 36130732 PMCID: PMC9561370 DOI: 10.1093/nar/gkac755] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 07/28/2022] [Accepted: 08/24/2022] [Indexed: 01/06/2023] Open
Abstract
Pioneer transcription factors are proteins that induce cellular identity transitions by binding to inaccessible regions of DNA in nuclear chromatin. They contribute to chromatin opening and recruit other factors to regulatory DNA elements. The structural features and dynamics modulating their interaction with nucleosomes are still unresolved. From a combination of experiments and molecular simulations, we reveal here how the pioneer factor and master regulator of pluripotency, Oct4, interprets and enhances nucleosome structural flexibility. The magnitude of Oct4’s impact on nucleosome dynamics depends on the binding site position and the mobility of the unstructured tails of nucleosomal histone proteins. Oct4 uses both its DNA binding domains to propagate and stabilize open nucleosome conformations, one for specific sequence recognition and the other for nonspecific interactions with nearby regions of DNA. Our findings provide a structural basis for the versatility of transcription factors in engaging with nucleosomes and have implications for understanding how pioneer factors induce chromatin dynamics.
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Affiliation(s)
- Caitlin M MacCarthy
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Jan Huertas
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany.,Yusuf Hamied Department of Chemistry, University of Cambridge, UK
| | - Claudia Ortmeier
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Hermann Vom Bruch
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Daisylyn Senna Tan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China
| | - Deike Reinke
- Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Astrid Sander
- Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | | | - Ralf Jauch
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China
| | - Hans R Schöler
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany.,Medical Faculty, University of Münster, Germany
| | - Vlad Cojocaru
- Department of Cellular and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany.,Computational Structural Biology Group, University of Utrecht, The Netherlands.,STAR-UBB Institute, Babeş-Bolyai University, Cluj-Napoca, Romania
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18
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Luzete-Monteiro E, Zaret KS. Structures and consequences of pioneer factor binding to nucleosomes. Curr Opin Struct Biol 2022; 75:102425. [PMID: 35863165 PMCID: PMC9976633 DOI: 10.1016/j.sbi.2022.102425] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/10/2022] [Accepted: 06/16/2022] [Indexed: 11/15/2022]
Abstract
Pioneer transcription factors are able to bind a partially exposed motif on the surface of a nucleosome, enabling the proteins to target sites in silent regions of chromatin that have been compacted by linker histone. The targeting of nucleosomal DNA by pioneer factors has been observed in vitro and in vivo, where binding can promote local nucleosome exposure that allows other transcription factors, nucleosome remodelers, and histone modifiers to engage the chromatin and elicit gene activation or further repression. Pioneer factors thereby establish new gene expression programs during cell fate changes that occur during embryonic development, regeneration, and cancer. Here, we review recent biophysical studies that reveal the structural features and strategies used by pioneer factors to accomplish nucleosome binding and the consequential changes to nucleosomes that can lead to DNA accessibility.
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Affiliation(s)
- Edgar Luzete-Monteiro
- Institute for Regenerative Medicine, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, 9-131 SCTR, 3400 Civic Center Blvd., Philadelphia, PA 19104-5157, USA.,Department of Biology, School of Arts and Sciences, University of Pennsylvania, 433 S University Ave, Philadelphia, PA 19104-4544
| | - Kenneth S. Zaret
- Institute for Regenerative Medicine, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, 9-131 SCTR, 3400 Civic Center Blvd., Philadelphia, PA 19104-5157, USA
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19
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Nakamura R, Nakayama JI. Multiple interfaces to recognize nucleosomal targets. J Biochem 2021; 171:257-259. [PMID: 34967395 DOI: 10.1093/jb/mvab139] [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: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 11/14/2022] Open
Abstract
In eukaryotic cells, DNA is tightly compacted as chromatin. Chromatin states must be dynamically changed to increase the accessibility of transcription factors to chromatin or to stably silence genes by higher-order chromatin structures known as heterochromatin. The regulation of chromatin needs cooperative action performed by a variety of proteins. Specific binding of transcription factors to target DNA is the initial step of chromatin regulation, and promotes changes in the post-translational modifications of histone tails, which themselves are recognized by a set of histone reader proteins. Recent biochemical studies have revealed that some transcription factors that recognize specific DNA sequences can also interact with histones. Furthermore, histone reader proteins that recognize specific histone tail modifications have been shown to have the ability to directly bind to DNA. In this commentary, we introduce recent advances in the elucidation of how chromatin regulating factors recognize nucleosomal targets.
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Affiliation(s)
- Rinko Nakamura
- Division of Chromatin Regulation, National Institute for Basic Biology, Okazaki 444-8585, Japan.,Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
| | - Jun-Ichi Nakayama
- Division of Chromatin Regulation, National Institute for Basic Biology, Okazaki 444-8585, Japan.,Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
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20
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Abstract
Transcription factors (TFs) are essential mediators of epigenetic regulation and modifiers of penetrance. Studies from the past decades have revealed a sub-class of TF that is capable of remodeling closed chromatin states through targeting nucleosomal motifs. This pioneer factor (PF) class of chromatin remodeler is ATP independent in its roles in epigenetic initiation, with nucleosome-motif recognition and association with repressive chromatin regions. Increasing evidence suggests that the fundamental properties of PFs can be coopted in human cancers. We explore the role of PFs in the larger context of tissue-specific epigenetic regulation. Moreover, we highlight an emerging class of chimeric PF derived from translocation partners in human disease and PFs associated with rare tumors. In the age of site-directed genome editing and targeted protein degradation, increasing our understanding of PFs will provide access to next-generation therapy for human disease driven from altered transcriptional circuitry.
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21
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Ray-Jones H, Spivakov M. Transcriptional enhancers and their communication with gene promoters. Cell Mol Life Sci 2021; 78:6453-6485. [PMID: 34414474 PMCID: PMC8558291 DOI: 10.1007/s00018-021-03903-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/08/2021] [Accepted: 07/19/2021] [Indexed: 12/13/2022]
Abstract
Transcriptional enhancers play a key role in the initiation and maintenance of gene expression programmes, particularly in metazoa. How these elements control their target genes in the right place and time is one of the most pertinent questions in functional genomics, with wide implications for most areas of biology. Here, we synthesise classic and recent evidence on the regulatory logic of enhancers, including the principles of enhancer organisation, factors that facilitate and delimit enhancer-promoter communication, and the joint effects of multiple enhancers. We show how modern approaches building on classic insights have begun to unravel the complexity of enhancer-promoter relationships, paving the way towards a quantitative understanding of gene control.
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Affiliation(s)
- Helen Ray-Jones
- MRC London Institute of Medical Sciences, London, W12 0NN, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College, London, W12 0NN, UK
| | - Mikhail Spivakov
- MRC London Institute of Medical Sciences, London, W12 0NN, UK.
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College, London, W12 0NN, UK.
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22
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Roberts GA, Ozkan B, Gachulincová I, O'Dwyer MR, Hall-Ponsele E, Saxena M, Robinson PJ, Soufi A. Dissecting OCT4 defines the role of nucleosome binding in pluripotency. Nat Cell Biol 2021; 23:834-845. [PMID: 34354236 PMCID: PMC7611526 DOI: 10.1038/s41556-021-00727-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 07/01/2021] [Indexed: 12/19/2022]
Abstract
Pioneer transcription factors such as OCT4 can target silent genes embedded in nucleosome-dense regions. How nucleosome interaction enables transcription factors to target chromatin and determine cell identity remains elusive. Here, we systematically dissect OCT4 to show that nucleosome binding is encoded within the DNA-binding domain and yet can be uncoupled from free-DNA binding. Furthermore, accelerating the binding kinetics of OCT4 to DNA enhances nucleosome binding. In cells, uncoupling nucleosome binding diminishes the ability of OCT4 to individually access closed chromatin, while more dynamic nucleosome binding results in expansive genome scanning within closed chromatin. However, both uncoupling and enhancing nucleosome binding are detrimental to inducing pluripotency from differentiated cells. Remarkably, stable interactions between OCT4 and nucleosomes are continuously required for maintaining the accessibility of pluripotency enhancers in stem cells. Our findings reveal how the affinity and residence time of OCT4-nucleosome complexes modulate chromatin accessibility during cell fate changes and maintenance.
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Affiliation(s)
- Gareth A Roberts
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute of Stem Cell Research, University of Edinburgh, Edinburgh, UK
| | - Burak Ozkan
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute of Stem Cell Research, University of Edinburgh, Edinburgh, UK
| | - Ivana Gachulincová
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute of Stem Cell Research, University of Edinburgh, Edinburgh, UK
| | - Michael R O'Dwyer
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute of Stem Cell Research, University of Edinburgh, Edinburgh, UK
| | - Elisa Hall-Ponsele
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute of Stem Cell Research, University of Edinburgh, Edinburgh, UK
| | - Manoj Saxena
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK
| | - Philip J Robinson
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK
| | - Abdenour Soufi
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, Institute of Stem Cell Research, University of Edinburgh, Edinburgh, UK.
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23
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Kagawa W, Kurumizaka H. Structural basis for DNA sequence recognition by pioneer factors in nucleosomes. Curr Opin Struct Biol 2021; 71:59-64. [PMID: 34218163 DOI: 10.1016/j.sbi.2021.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 05/12/2021] [Indexed: 12/20/2022]
Abstract
Most of the genomic DNA in eukaryotes is bound to histone complexes, which hinders transcription factors from accessing their target DNA sequences. Here, we discuss recent structural insights into the mechanisms by which pioneer factors, an emerging class of transcription factors, can recognize DNA motifs located on the nucleosome surface.
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Affiliation(s)
- Wataru Kagawa
- Department of Chemistry, Graduate School of Science and Engineering, Meisei University, 2-1-1 Hodokubo, Hino-shi, Tokyo, 191-8506, Japan
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan.
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24
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Michael AK, Thomä NH. Reading the chromatinized genome. Cell 2021; 184:3599-3611. [PMID: 34146479 DOI: 10.1016/j.cell.2021.05.029] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/11/2021] [Accepted: 05/19/2021] [Indexed: 02/07/2023]
Abstract
Eukaryotic DNA-binding proteins operate in the context of chromatin, where nucleosomes are the elementary building blocks. Nucleosomal DNA is wrapped around a histone core, thereby rendering a large fraction of the DNA surface inaccessible to DNA-binding proteins. Nevertheless, first responders in DNA repair and sequence-specific transcription factors bind DNA target sites obstructed by chromatin. While early studies examined protein binding to histone-free DNA, it is only now beginning to emerge how DNA sequences are interrogated on nucleosomes. These readout strategies range from the release of nucleosomal DNA from histones, to rotational/translation register shifts of the DNA motif, and nucleosome-specific DNA binding modes that differ from those observed on naked DNA. Since DNA motif engagement on nucleosomes strongly depends on position and orientation, we argue that motif location and nucleosome positioning co-determine protein access to DNA in transcription and DNA repair.
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Affiliation(s)
- Alicia K Michael
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Nicolas H Thomä
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
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25
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Generation of biologically active recombinant human OCT4 protein from E. coli. 3 Biotech 2021; 11:207. [PMID: 33927995 DOI: 10.1007/s13205-021-02758-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 03/27/2021] [Indexed: 02/06/2023] Open
Abstract
Octamer-binding transcription factor 4 (OCT4) is vital for early embryonic development and is a master regulator of pluripotency in embryonic stem cells. Notably, OCT4 is a key reprogramming factor to derive induced pluripotent stem cells, which have tremendous prospects in regenerative medicine. In the current study, we report heterologous expression and purification of human OCT4 in E. coli to produce pure recombinant protein under native conditions. To achieve this, the 1083 bp coding sequence of the human OCT4 gene was codon-optimized for heterologous expression in E. coli. The codon-optimized sequence was fused with fusion tags, namely a cell-penetrating peptide sequence for intracellular delivery, a nuclear localization sequence for intranuclear delivery, and a His-tag for affinity purification. Subsequently, the codon-optimized sequence and the fusion tags were cloned in the protein expression vector, pET28a(+), and transformed into E. coli strain BL21(DE3) for expression. The recombinant OCT4 protein was purified from the soluble fraction under native conditions using immobilized metal ion affinity chromatography in a facile manner, and its identity was confirmed by Western blotting and mass spectrometry. Furthermore, the secondary structure of the recombinant protein was analyzed using far ultraviolet circular dichroism spectroscopy, which confirmed that the purified fusion protein maintained a secondary structure conformation, and it predominantly composed of α-helices. Next, the recombinant OCT4 protein was applied to human cells, and was found that it was able to enter the cells and translocate to the nucleus. Furthermore, the biological activity of the transduced OCT4 protein was also demonstrated on human cells. This recombinant tool can substitute for genetic and viral forms of OCT4 to enable the derivation of integration-free pluripotent cells. It can also be used to elucidate its biological role in various cellular processes and diseases and for structural and biochemical studies. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13205-021-02758-z.
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26
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Structures of chromatin modulators in complex with nucleosome. Curr Opin Chem Biol 2021; 63:105-114. [PMID: 33823458 DOI: 10.1016/j.cbpa.2021.02.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 02/11/2021] [Accepted: 02/25/2021] [Indexed: 12/17/2022]
Abstract
The chromatin structure is dynamically regulated by many different modulators that post-translationally modify histones, replace canonical histones with histone variants, and unwind nucleosomal DNA, thereby modulating the accessibility of nucleosomal DNA and facilitating downstream DNA-templated nuclear processes. To understand how these modulators change the chromatin structure, it is essential to determine the 3D structures of chromatin modulators in complex with nucleosome. Here, we review the very recent progress in structural studies of some selected chromatin modulators in complex with nucleosome, including those of histone demethylases LSD1/2, some pioneer transcription factors, and the PWWP domain-containing protein LEDGF.
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27
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Kishan KC, Subramanya SK, Li R, Cui F. Machine learning predicts nucleosome binding modes of transcription factors. BMC Bioinformatics 2021; 22:166. [PMID: 33784978 PMCID: PMC8008688 DOI: 10.1186/s12859-021-04093-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/18/2021] [Indexed: 11/24/2022] Open
Abstract
Background Most transcription factors (TFs) compete with nucleosomes to gain access to their cognate binding sites. Recent studies have identified several TF-nucleosome interaction modes including end binding (EB), oriented binding, periodic binding, dyad binding, groove binding, and gyre spanning. However, there are substantial experimental challenges in measuring nucleosome binding modes for thousands of TFs in different species. Results We present a computational prediction of the binding modes based on TF protein sequences. With a nested cross-validation procedure, our model outperforms several fine-tuned off-the-shelf machine learning (ML) methods in the multi-label classification task. Our binary classifier for the EB mode performs better than these ML methods with the area under precision-recall curve achieving 75%. The end preference of most TFs is consistent with low nucleosome occupancy around their binding site in GM12878 cells. The nucleosome occupancy data is used as an alternative dataset to confirm the superiority of our EB classifier. Conclusions We develop the first ML-based approach for efficient and comprehensive analysis of nucleosome binding modes of TFs. Supplementary Information The online version contains supplementary material available at 10.1186/s12859-021-04093-9.
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Affiliation(s)
- K C Kishan
- Golisano College of Computing and Information Sciences, Rochester Institute of Technology, 20 Lomb Memorial Drive, Rochester, NY, 14623, USA
| | - Sridevi K Subramanya
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, 1 Lomb Memorial Drive, Rochester, NY, 14623, USA
| | - Rui Li
- Golisano College of Computing and Information Sciences, Rochester Institute of Technology, 20 Lomb Memorial Drive, Rochester, NY, 14623, USA
| | - Feng Cui
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, 1 Lomb Memorial Drive, Rochester, NY, 14623, USA.
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Kurumizaka H, Kujirai T, Takizawa Y. Contributions of Histone Variants in Nucleosome Structure and Function. J Mol Biol 2020; 433:166678. [PMID: 33065110 DOI: 10.1016/j.jmb.2020.10.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/08/2020] [Accepted: 10/08/2020] [Indexed: 11/19/2022]
Abstract
Chromatin compacts genomic DNA in eukaryotes. The primary chromatin unit is the nucleosome core particle, composed of four pairs of the core histones, H2A, H2B, H3, and H4, and 145-147 base pairs of DNA. Since replication, recombination, repair, and transcription take place in chromatin, the structure and dynamics of the nucleosome must be versatile. These nucleosome characteristics underlie the epigenetic regulation of genomic DNA. In higher eukaryotes, many histone variants have been identified as non-allelic isoforms, which confer nucleosome diversity. In this article, we review the manifold types of nucleosomes produced by histone variants, which play important roles in the epigenetic regulation of chromatin.
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Affiliation(s)
- Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
| | - Tomoya Kujirai
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Yoshimasa Takizawa
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
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Bai Y, Zhou BR. Structures of Native-like Nucleosomes: One Step Closer toward Understanding the Structure and Function of Chromatin. J Mol Biol 2020; 433:166648. [PMID: 32920051 DOI: 10.1016/j.jmb.2020.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 02/08/2023]
Abstract
Genomic DNA in eukaryotes is organized into chromatin through association with core histone proteins to form nucleosomes. To understand the structure and function of chromatin, we must determine the structures of nucleosomes containing native DNA sequences. However, to date, our knowledge of nucleosome structures is mainly based on the crystallographic studies of the nucleosomes containing non-native DNA sequences. Here, we discuss the technical issues related to the determination of the nucleosome structures and review the few structural studies on native-like nucleosomes. We show how an antibody fragment-aided single-particle cryo-EM can be a useful method to determine the structures of nucleosomes containing genomic DNA. Finally, we provide a perspective for future structural studies of some native-like nucleosomes that play critical roles in chromatin functions.
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Affiliation(s)
- Yawen Bai
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Bing-Rui Zhou
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Abstract
Pioneer transcription factors have the intrinsic biochemical ability to scan partial DNA sequence motifs that are exposed on the surface of a nucleosome and thus access silent genes that are inaccessible to other transcription factors. Pioneer factors subsequently enable other transcription factors, nucleosome remodeling complexes, and histone modifiers to engage chromatin, thereby initiating the formation of an activating or repressive regulatory sequence. Thus, pioneer factors endow the competence for fate changes in embryonic development, are essential for cellular reprogramming, and rewire gene networks in cancer cells. Recent studies with reconstituted nucleosomes in vitro and chromatin binding in vivo reveal that pioneer factors can directly perturb nucleosome structure and chromatin accessibility in different ways. This review focuses on our current understanding of the mechanisms by which pioneer factors initiate gene network changes and will ultimately contribute to our ability to control cell fates at will.
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Affiliation(s)
- Kenneth S Zaret
- Institute for Regenerative Medicine, Epigenetics Institute, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-5157, USA;
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