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In vitro single molecule and bulk phase studies reveal the AP-1 transcription factor cFos binds to DNA without its partner cJun. J Biol Chem 2022; 298:102229. [PMID: 35787376 PMCID: PMC9364023 DOI: 10.1016/j.jbc.2022.102229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/27/2022] [Accepted: 06/29/2022] [Indexed: 11/23/2022] Open
Abstract
The AP-1 transcription factor family crucially regulates progression of the cell cycle, as well as playing roles in proliferation, differentiation, and the stress response. The two best described AP-1 family members, cFos and cJun, are known to dimerize to form a functional AP-1 heterodimer that binds to a consensus response element sequence. Although cJun can also homodimerize and bind to DNA, the canonical view is that cFos cannot bind DNA without heterodimerizing with cJun. Here, we show that cFos can actually bind to DNA in the absence of cJun in vitro. Using dual color single molecule imaging of cFos alone, we directly visualize binding to and movement on DNA. Of all these DNA-bound proteins, detailed analysis suggested 30 to 46% were homodimers. Furthermore, we constructed fluorescent protein fusions of cFos and cJun for Förster resonance energy transfer experiments. These constructs indicated complete dimerization of cJun, but although cFos could dimerize, its extent was reduced. Finally, to provide orthogonal confirmation of cFos binding to DNA, we performed bulk-phase circular dichroism experiments that showed clear structural changes in DNA; these were found to be specific to the AP-1 consensus sequence. Taken together, our results clearly show cFos can interact with DNA both as monomers and dimers independently of its archetypal partner, cJun.
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2
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Wang JS, Kamath T, Mazur CM, Mirzamohammadi F, Rotter D, Hojo H, Castro CD, Tokavanich N, Patel R, Govea N, Enishi T, Wu Y, da Silva Martins J, Bruce M, Brooks DJ, Bouxsein ML, Tokarz D, Lin CP, Abdul A, Macosko EZ, Fiscaletti M, Munns CF, Ryder P, Kost-Alimova M, Byrne P, Cimini B, Fujiwara M, Kronenberg HM, Wein MN. Control of osteocyte dendrite formation by Sp7 and its target gene osteocrin. Nat Commun 2021; 12:6271. [PMID: 34725346 PMCID: PMC8560803 DOI: 10.1038/s41467-021-26571-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 10/12/2021] [Indexed: 02/05/2023] Open
Abstract
Some osteoblasts embed within bone matrix, change shape, and become dendrite-bearing osteocytes. The circuitry that drives dendrite formation during "osteocytogenesis" is poorly understood. Here we show that deletion of Sp7 in osteoblasts and osteocytes causes defects in osteocyte dendrites. Profiling of Sp7 target genes and binding sites reveals unexpected repurposing of this transcription factor to drive dendrite formation. Osteocrin is a Sp7 target gene that promotes osteocyte dendrite formation and rescues defects in Sp7-deficient mice. Single-cell RNA-sequencing demonstrates defects in osteocyte maturation in the absence of Sp7. Sp7-dependent osteocyte gene networks are associated with human skeletal diseases. Moreover, humans with a SP7R316C mutation show defective osteocyte morphology. Sp7-dependent genes that mark osteocytes are enriched in neurons, highlighting shared features between osteocytic and neuronal connectivity. These findings reveal a role for Sp7 and its target gene Osteocrin in osteocytogenesis, revealing that pathways that control osteocyte development influence human bone diseases.
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Affiliation(s)
- Jialiang S Wang
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tushar Kamath
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Courtney M Mazur
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Fatemeh Mirzamohammadi
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Plastic and Reconstructive Surgery, Wright State University, Dayton, OH, USA
| | - Daniel Rotter
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- University of Applied Sciences Technikum Wien, Vienna, Austria
| | - Hironori Hojo
- Center for Disease Biology and Integrative Medicine, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Christian D Castro
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Nicha Tokavanich
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Rushi Patel
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Nicolas Govea
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Anesthesiology, Weill Cornell Medical School, New York, NY, USA
| | - Tetsuya Enishi
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Orthopedic Surgery, Tokushima Municipal Hospital, Tokushima, Japan
| | - Yunshu Wu
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | | | - Michael Bruce
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Daniel J Brooks
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Center for Advanced Orthopedic Studies, Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MaA, USA
| | - Mary L Bouxsein
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Center for Advanced Orthopedic Studies, Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MaA, USA
| | - Danielle Tokarz
- Advanced Microscopy Program, Center for Systems Biology and Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Chemistry, Saint Mary's University, Halifax, Canada
| | - Charles P Lin
- Advanced Microscopy Program, Center for Systems Biology and Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Abdul Abdul
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Evan Z Macosko
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Melissa Fiscaletti
- Pediatric Department, Sainte-Justine University Hospital Centre, Montreal, Canada
| | - Craig F Munns
- Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Sydney, NSW, Australia
- Discipline of Paediatrics & Child Health, University of Sydney, Sydney, 2006, Australia
| | - Pearl Ryder
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Broad Institute of Harvard and MIT, Imaging Platform, Cambridge, MA, USA
| | - Maria Kost-Alimova
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Broad Institute of Harvard and MIT, Center for the Development of Therapeutics, Cambridge, MA, USA
| | - Patrick Byrne
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Broad Institute of Harvard and MIT, Center for the Development of Therapeutics, Cambridge, MA, USA
| | - Beth Cimini
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Broad Institute of Harvard and MIT, Imaging Platform, Cambridge, MA, USA
| | - Makoto Fujiwara
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Henry M Kronenberg
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Marc N Wein
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
- Broad Institute of Harvard and MIT, Cambridge, MA, USA.
- Harvard Stem Cell Institute, Cambridge, MA, USA.
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3
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Hörberg J, Moreau K, Tamás MJ, Reymer A. Sequence-specific dynamics of DNA response elements and their flanking sites regulate the recognition by AP-1 transcription factors. Nucleic Acids Res 2021; 49:9280-9293. [PMID: 34387667 PMCID: PMC8450079 DOI: 10.1093/nar/gkab691] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/21/2021] [Accepted: 07/27/2021] [Indexed: 11/28/2022] Open
Abstract
Activator proteins 1 (AP-1) comprise one of the largest families of eukaryotic basic leucine zipper transcription factors. Despite advances in the characterization of AP-1 DNA-binding sites, our ability to predict new binding sites and explain how the proteins achieve different gene expression levels remains limited. Here we address the role of sequence-specific DNA flexibility for stability and specific binding of AP-1 factors, using microsecond-long molecular dynamics simulations. As a model system, we employ yeast AP-1 factor Yap1 binding to three different response elements from two genetic environments. Our data show that Yap1 actively exploits the sequence-specific flexibility of DNA within the response element to form stable protein–DNA complexes. The stability also depends on the four to six flanking nucleotides, adjacent to the response elements. The flanking sequences modulate the conformational adaptability of the response element, making it more shape-efficient to form specific contacts with the protein. Bioinformatics analysis of differential expression of the studied genes supports our conclusions: the stability of Yap1–DNA complexes, modulated by the flanking environment, influences the gene expression levels. Our results provide new insights into mechanisms of protein–DNA recognition and the biological regulation of gene expression levels in eukaryotes.
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Affiliation(s)
- Johanna Hörberg
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg 40530, Sweden
| | - Kevin Moreau
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg 40530, Sweden
| | - Markus J Tamás
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg 40530, Sweden
| | - Anna Reymer
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg 40530, Sweden
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4
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Bie LH, Fei JW, Gao J. Molecular mechanism of methyl-dependent and spatial-specific DNA recognition of c-Jun homodimer. J Mol Model 2021; 27:227. [PMID: 34264385 DOI: 10.1007/s00894-021-04840-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 07/01/2021] [Indexed: 10/20/2022]
Abstract
DNA methylation is important in regulation of gene expression and normal development because it alters the interplay between protein and DNA. Experiments have shown that a single 5-methylcytosine at different CpG sites (mCpG) might have different effects on specific recognition, but the atomistic origin and dynamic details are largely unclear. In this work, we investigated the mechanism of monomethylation at different CpG sites in the cognate motif and the cooperativity of full methylation. By constructing four models of c-Jun/Jun protein binding to the 5[Formula: see text]-XGAGTCA-3[Formula: see text] (X represents C or methylated C) motif, we characterized the dynamics of the contact interface using the all-atom molecular dynamics method. Free energy analysis of MM/GBSA suggests that regardless of whether the C12pG13 site of the bottom strand is methylated, the effects from mC25 of the top strand are dominant and can moderately enhance the binding by [Formula: see text] 31 kcal/mol, whereas mC12 showed a relatively small contribution, in agreement with the experimental data. Remarkably, we found that this spatial-specific influence was induced by different regulatory rules. The influence of the mC25 site is mainly mediated by steric hindrance. The additional methyl group leads to the conformational changes in nearby residues and triggers an obvious structural bending in the protein, which results in the formation of a new T-Asn-C triad that enhances the specific recognition of TCA half-sites. The substitution of the methyl group at the mC12 site of the bottom strand breaks the original H-bonds directly. Such changes in electrostatic interactions also lead to the remote allosteric effects of protein by multifaceted interactions but have negligible contributions to binding. Although these two influence modes are different, they can both fine-tune the local environment, which might produce remote allosteric effects through protein-protein interactions. Further analysis reveals that the discrepancies in these two modes are primarily due to their location. Moreover, when both sites are methylated, the major determinant of binding specificity depends on the context and the location of the methylation site, which is the result of crosstalk and cooperativity.
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Affiliation(s)
- Li-Hua Bie
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jun-Wen Fei
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jun Gao
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
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5
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Vidal RL, Sepulveda D, Troncoso-Escudero P, Garcia-Huerta P, Gonzalez C, Plate L, Jerez C, Canovas J, Rivera CA, Castillo V, Cisternas M, Leal S, Martinez A, Grandjean J, Sonia D, Lashuel HA, Martin AJM, Latapiat V, Matus S, Sardi SP, Wiseman RL, Hetz C. Enforced dimerization between XBP1s and ATF6f enhances the protective effects of the UPR in models of neurodegeneration. Mol Ther 2021; 29:1862-1882. [PMID: 33545358 PMCID: PMC8116614 DOI: 10.1016/j.ymthe.2021.01.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 11/14/2020] [Accepted: 01/21/2021] [Indexed: 02/07/2023] Open
Abstract
Alteration to endoplasmic reticulum (ER) proteostasis is observed in a variety of neurodegenerative diseases associated with abnormal protein aggregation. Activation of the unfolded protein response (UPR) enables an adaptive reaction to recover ER proteostasis and cell function. The UPR is initiated by specialized stress sensors that engage gene expression programs through the concerted action of the transcription factors ATF4, ATF6f, and XBP1s. Although UPR signaling is generally studied as unique linear signaling branches, correlative evidence suggests that ATF6f and XBP1s may physically interact to regulate a subset of UPR target genes. In this study, we designed an ATF6f/XBP1s fusion protein termed UPRplus that behaves as a heterodimer in terms of its selective transcriptional activity. Cell-based studies demonstrated that UPRplus has a stronger effect in reducing the abnormal aggregation of mutant huntingtin and α-synuclein when compared to XBP1s or ATF6 alone. We developed a gene transfer approach to deliver UPRplus into the brain using adeno-associated viruses (AAVs) and demonstrated potent neuroprotection in vivo in preclinical models of Parkinson's disease and Huntington's disease. These results support the concept in which directing UPR-mediated gene expression toward specific adaptive programs may serve as a possible strategy to optimize the beneficial effects of the pathway in different disease conditions.
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Affiliation(s)
- René L Vidal
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile.
| | - Denisse Sepulveda
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | - Paulina Troncoso-Escudero
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Paula Garcia-Huerta
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Constanza Gonzalez
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Lars Plate
- Department of Chemistry, Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA; Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Carolina Jerez
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | - José Canovas
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Claudia A Rivera
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | - Valentina Castillo
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | - Marisol Cisternas
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | - Sirley Leal
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | - Alexis Martinez
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Julia Grandjean
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Donzelli Sonia
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Alberto J M Martin
- Laboratorio de Biología de Redes, Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Veronica Latapiat
- Laboratorio de Biología de Redes, Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Soledad Matus
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Fundacion Ciencia Vida, Santiago 7780272, Chile; Facultad de Medicina y Ciencia, Universidad San Sebastián, Providencia 7510157, Santiago, Chile
| | - S Pablo Sardi
- Rare and Neurological Diseases Therapeutic Area, Sanofi, 49 New York Avenue, Framingham, MA, USA
| | - R Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Claudio Hetz
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile; Buck Institute for Research on Aging, Novato, CA 94945, USA.
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6
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Georgakopoulos-Soares I, Mouratidis I, Parada GE, Matharu N, Hemberg M, Ahituv N. Asymmetron: a toolkit for the identification of strand asymmetry patterns in biological sequences. Nucleic Acids Res 2021; 49:e4. [PMID: 33211865 PMCID: PMC7797064 DOI: 10.1093/nar/gkaa1052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/15/2020] [Accepted: 10/20/2020] [Indexed: 11/23/2022] Open
Abstract
DNA strand asymmetries can have a major effect on several biological functions, including replication, transcription and transcription factor binding. As such, DNA strand asymmetries and mutational strand bias can provide information about biological function. However, a versatile tool to explore this does not exist. Here, we present Asymmetron, a user-friendly computational tool that performs statistical analysis and visualizations for the evaluation of strand asymmetries. Asymmetron takes as input DNA features provided with strand annotation and outputs strand asymmetries for consecutive occurrences of a single DNA feature or between pairs of features. We illustrate the use of Asymmetron by identifying transcriptional and replicative strand asymmetries of germline structural variant breakpoints. We also show that the orientation of the binding sites of 45% of human transcription factors analyzed have a significant DNA strand bias in transcribed regions, that is also corroborated in ChIP-seq analyses, and is likely associated with transcription. In summary, we provide a novel tool to assess DNA strand asymmetries and show how it can be used to derive new insights across a variety of biological disciplines.
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Affiliation(s)
- Ilias Georgakopoulos-Soares
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
| | - Ioannis Mouratidis
- Aristotle University of Thessaloniki, Department of Mathematics, Thessaloniki, GR, Greece
| | - Guillermo E Parada
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Navneet Matharu
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
- Innovative Genomics Institute, University of California San Francisco, San Francisco, CA, USA
| | - Martin Hemberg
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Nadav Ahituv
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
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7
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Brennan A, Leech JT, Kad NM, Mason JM. Selective antagonism of cJun for cancer therapy. J Exp Clin Cancer Res 2020; 39:184. [PMID: 32917236 PMCID: PMC7488417 DOI: 10.1186/s13046-020-01686-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 08/20/2020] [Indexed: 01/10/2023] Open
Abstract
The activator protein-1 (AP-1) family of transcription factors modulate a diverse range of cellular signalling pathways into outputs which can be oncogenic or anti-oncogenic. The transcription of relevant genes is controlled by the cellular context, and in particular by the dimeric composition of AP-1. Here, we describe the evidence linking cJun in particular to a range of cancers. This includes correlative studies of protein levels in patient tumour samples and mechanistic understanding of the role of cJun in cancer cell models. This develops an understanding of cJun as a focal point of cancer-altered signalling which has the potential for therapeutic antagonism. Significant work has produced a range of small molecules and peptides which have been summarised here and categorised according to the binding surface they target within the cJun-DNA complex. We highlight the importance of selectively targeting a single AP-1 family member to antagonise known oncogenic function and avoid antagonism of anti-oncogenic function.
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Affiliation(s)
- Andrew Brennan
- Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - James T Leech
- School of Biosciences, University of Kent, Canterbury, CT2 7NH, UK
| | - Neil M Kad
- School of Biosciences, University of Kent, Canterbury, CT2 7NH, UK
| | - Jody M Mason
- Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
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8
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DNA sequence context as a marker of CpG methylation instability in normal and cancer tissues. Sci Rep 2020; 10:1721. [PMID: 32015379 PMCID: PMC6997448 DOI: 10.1038/s41598-020-58331-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 01/13/2020] [Indexed: 11/09/2022] Open
Abstract
DNA methylation alterations are related to multiple molecular mechanisms. The DNA context of CpG sites plays a crucial role in the maintenance and stability of methylation patterns. The quantitative relationship between DNA composition and DNA methylation has been studied in normal as well as pathological conditions, showing that DNA methylation status is highly dependent on the local sequence context. In this work, we describe this relationship by analyzing the DNA sequence context associated to methylation profiles in both physiological and pathological conditions. In particular, we used DNA motifs to describe methylation stability patterns in normal tissues and aberrant methylation events in cancer lesions. In this manuscript, we show how different groups of DNA sequences can be related to specific epigenetic events, across normal and cancer tissues, and provide a thorough structural and functional characterization of these sequences.
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9
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Bejjani F, Evanno E, Zibara K, Piechaczyk M, Jariel-Encontre I. The AP-1 transcriptional complex: Local switch or remote command? Biochim Biophys Acta Rev Cancer 2019; 1872:11-23. [PMID: 31034924 DOI: 10.1016/j.bbcan.2019.04.003] [Citation(s) in RCA: 140] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/19/2019] [Accepted: 04/22/2019] [Indexed: 12/19/2022]
Abstract
The ubiquitous family of AP-1 dimeric transcription complexes is involved in virtually all cellular and physiological functions. It is paramount for cells to reprogram gene expression in response to cues of many sorts and is involved in many tumorigenic processes. How AP-1 controls gene transcription has largely remained elusive till recently. The advent of the "omics" technologies permitting genome-wide studies of transcription factors has however changed and improved our view of AP-1 mechanistical actions. If these studies confirm that AP-1 can sometimes act as a local transcriptional switch operating in the vicinity of transcription start sites (TSS), they strikingly indicate that AP-1 principally operates as a remote command binding to distal enhancers, placing chromatin architecture dynamics at the heart of its transcriptional actions. They also unveil novel constraints operating on AP-1, as well as novel mechanisms used to regulate gene expression via transcription-pioneering-, chromatin-remodeling- and chromatin accessibility maintenance effects.
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Affiliation(s)
- Fabienne Bejjani
- Equipe Labellisée Ligue Nationale contre le Cancer, Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France; PRASE and Biology Department, Faculty of Sciences - I, Lebanese University, Beirut, Lebanon
| | - Emilie Evanno
- Equipe Labellisée Ligue Nationale contre le Cancer, Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Kazem Zibara
- PRASE and Biology Department, Faculty of Sciences - I, Lebanese University, Beirut, Lebanon
| | - Marc Piechaczyk
- Equipe Labellisée Ligue Nationale contre le Cancer, Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France.
| | - Isabelle Jariel-Encontre
- Equipe Labellisée Ligue Nationale contre le Cancer, Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France.
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10
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Kang SK, Chu XY, Tian T, Dong PF, Chen BX, Zhang HY. Why the c-Fos/c-Jun complex is extremely conserved: An in vitro evolution exploration by combining cDNA display and proximity ligation. FEBS Lett 2019; 593:1040-1049. [PMID: 31002393 DOI: 10.1002/1873-3468.13388] [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: 02/08/2019] [Revised: 03/31/2019] [Accepted: 04/10/2019] [Indexed: 11/08/2022]
Abstract
Transcriptional regulation involves a series of sophisticated protein-protein and protein-DNA interactions (PPI and PDI). Some transcriptional complexes, such as c-Fos/c-Jun and their binding DNA fragments, have been conserved over the past one billion years. Considering the thermodynamic principle for transcriptional complex formation, we hypothesized that the c-Fos/c-Jun complex may represent a thermodynamic summit in the evolutionary space. To test this, we invented a new method, termed One-Pot-seq, which combines cDNA display and proximity ligation to analyse PPI/PDI complexes simultaneously. We found that the wild-type c-Fos/c-Jun complex is indeed the most thermodynamically stable relative to various mutants of c-Fos/c-Jun and binding DNA fragments. Our method also provides a universal approach to detect transcriptional complexes and explore transcriptional regulation mechanisms.
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Affiliation(s)
- Shou-Kai Kang
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, China
| | - Xin-Yi Chu
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, China
| | - Tian Tian
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, China
| | - Peng-Fei Dong
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, China
| | - Bai-Xue Chen
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, China
| | - Hong-Yu Zhang
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, China
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11
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Yu P, Wang C, Chen P, Lee M. YAP1 homologue-mediated redox sensing is crucial for a successful infection by Monilinia fructicola. MOLECULAR PLANT PATHOLOGY 2017; 18:783-797. [PMID: 27239957 PMCID: PMC6638302 DOI: 10.1111/mpp.12438] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 05/17/2016] [Accepted: 05/26/2016] [Indexed: 05/20/2023]
Abstract
Monilinia fructicola (G. Winter) Honey is a devastating pathogen on Rosaceae which causes blossom blight and fruit rot. Only a few studies related to the plant-pathogen interaction have been published and there is limited knowledge on the relationship between oxidative stress and successful infection in M. fructicola. In this study, we cloned and characterized a redox-responsive transcription factor MFAP1, a YAP1 homologue. MfAP1-silenced strains were generated by polyethylene glycol-mediated protoplast transformation or Agrobacterium T-DNA-mediated transformation. Pathogenicity assay demonstrated that MfAP1-silenced strains caused smaller lesions on rose and peach petals. Transformants carrying extra copies of MfAP1, driven by the native promoter, were generated for MfAP1 overexpression. Interestingly, MfAP1-overexpressing strains also caused smaller lesions on rose petals. Strains carrying two copies of MfAP1 accumulated reactive oxygen species (ROS) at higher levels and exhibited delayed accumulation of MfAP1 transcripts compared with the wild-type during pathogenesis. By the analysis of ROS production and the expression patterns of redox- and virulence-related genes in the wild-type strain and an MfAP1-overexpressing strain, we found that the M. fructicola wild-type strain responded to oxidative stress at the infection site, activated the expression of MfAP1 and up-regulated the genes required for ROS detoxification and fungal virulence. In contrast, MfAP1 expression in the MfAP1-overexpressing strain was suppressed after the induction of a strong oxidative burst at the infection site, altering the expression of ROS detoxification and virulence-related genes. Our results highlight the importance of MfAP1 and ROS accumulation in the successful infection of M. fructicola.
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Affiliation(s)
- Pei‐Ling Yu
- Department of Plant PathologyNational Chung‐Hsing University250 Kuo‐Kuang Rd.Taichung402Taiwan
- NCHU‐UCD Plant and Food Biotechnology CenterNational Chung‐Hsing University250 Kuo‐Kuang Rd.Taichung402Taiwan
- Agricultural Biotechnology CenterNational Chung‐Hsing University250 Kuo‐Kuang Rd.Taichung402Taiwan
| | - Chih‐Li Wang
- Department of Plant PathologyNational Chung‐Hsing University250 Kuo‐Kuang Rd.Taichung402Taiwan
| | - Pei‐Yin Chen
- Department of Plant PathologyNational Chung‐Hsing University250 Kuo‐Kuang Rd.Taichung402Taiwan
| | - Miin‐Huey Lee
- Department of Plant PathologyNational Chung‐Hsing University250 Kuo‐Kuang Rd.Taichung402Taiwan
- NCHU‐UCD Plant and Food Biotechnology CenterNational Chung‐Hsing University250 Kuo‐Kuang Rd.Taichung402Taiwan
- Agricultural Biotechnology CenterNational Chung‐Hsing University250 Kuo‐Kuang Rd.Taichung402Taiwan
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12
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Chan JSK, Tan MJ, Sng MK, Teo Z, Phua T, Choo CC, Li L, Zhu P, Tan NS. Cancer-associated fibroblasts enact field cancerization by promoting extratumoral oxidative stress. Cell Death Dis 2017; 8:e2562. [PMID: 28102840 PMCID: PMC5386391 DOI: 10.1038/cddis.2016.492] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 12/22/2016] [Accepted: 12/22/2016] [Indexed: 12/24/2022]
Abstract
Histological inspection of visually normal tissue adjacent to neoplastic lesions often reveals multiple foci of cellular abnormalities. This suggests the presence of a regional carcinogenic signal that spreads oncogenic transformation and field cancerization. We observed an abundance of mutagenic reactive oxygen species in the stroma of cryosectioned patient tumor biopsies, indicative of extratumoral oxidative stress. Diffusible hydrogen peroxide (H2O2) was elevated in the conditioned medium of cultured skin epithelia at various stages of oncogenic transformation, and H2O2 production increased with greater tumor-forming and metastatic capacity of the studied cell lines. Explanted cancer-associated fibroblasts (CAFs) also had higher levels of H2O2 secretion compared with normal fibroblasts (FIBs). These results suggest that extracellular H2O2 acts as a field effect carcinogen. Indeed, H2O2-treated keratinocytes displayed decreased phosphatase and tensin homolog (PTEN) and increased Src activities because of oxidative modification. Furthermore, treating FIBs with CAF-conditioned medium or exogenous H2O2 resulted in the acquisition of an oxidative, CAF-like state. In vivo, the proliferative potential and invasiveness of composite tumor xenografts comprising cancerous or non-tumor-forming epithelia with CAFs and FIBs could be attenuated by the presence of catalase. Importantly, we showed that oxidatively transformed FIBs isolated from composite tumor xenografts retained their ability to promote tumor growth and aggressiveness when adoptively transferred into new xenografts. Higher H2O2 production by CAFs was contingent on impaired TGFβ signaling leading to the suppression of the antioxidant enzyme glutathione peroxidase 1 (GPX1). Finally, we detected a reduction in Smad3, TAK1 and TGFβRII expression in a cohort of 197 clinical squamous cell carcinoma (SCC) CAFs, suggesting that impaired stromal TGFβ signaling may be a clinical feature of SCC. Our study indicated that CAFs and cancer cells engage redox signaling circuitries and mitogenic signaling to reinforce their reciprocal relationship, suggesting that future anticancer approaches should simultaneously target ligand receptor and redox-mediated pathways.
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Affiliation(s)
- Jeremy Soon Kiat Chan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore
| | - Ming Jie Tan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore
| | - Ming Keat Sng
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore
| | - Ziqiang Teo
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore
| | - Terri Phua
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore.,Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, StockholmSweden
| | - Chee Chong Choo
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore
| | - Liang Li
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore
| | - Pengcheng Zhu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore
| | - Nguan Soon Tan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, 50 Nanyang Avenue, Singapore.,Institute of Molecular and Cell Biology, A*STAR, 61 Biopolis Drive, Proteos, Singapore.,KK Women's and Children Hospital, 100 Bukit Timah Road, Singapore
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13
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Abstract
UNLABELLED Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, regulates both survival and differentiation of several neuronal populations in the nervous system during development, as well as synaptic plasticity in the adult brain. BDNF exerts its biological functions through its receptor TrkB. Although the regulation of BDNF transcription by neuronal activity has been widely studied, little is known about TrkB signaling-dependent expression of BDNF. Using rat primary cortical neuron cultures, we show that the BDNF gene is a subject to an extensive autoregulatory loop, where TrkB signaling upregulates the expression of all major BDNF transcripts, mainly through activating MAPK pathways. Investigating the mechanisms behind this autoregulation, we found that AP-1 transcription factors, comprising Jun and Fos family members, participate in the induction of BDNF exon I, III, and VI transcripts. AP-1 transcription factors directly upregulate the expression of exon I transcripts by binding two novel AP-1 cis-elements in promoter I. Moreover, our results show that the effect of AP-1 proteins on the activity of rat BDNF promoters III and VI is indirect, because AP-1 proteins were not detected to bind the respective promoter regions by chromatin immunoprecipitation (ChIP). Collectively, we describe an extensive positive feedback system in BDNF regulation, adding a new layer to the elaborate control of BDNF gene expression. SIGNIFICANCE STATEMENT Here, we show for the first time that in rat primary cortical neurons the expression of all major BDNF transcripts (exon I, II, III, IV, VI, and IXa transcripts) is upregulated in response to TrkB signaling, and that AP-1 transcription factors participate in the induction of exon I, III, and VI transcripts. Moreover, we have described two novel functional AP-1 cis-elements in BDNF promoter I, responsible for the activation of the promoter in response to TrkB signaling. Our results indicate the existence of a positive feedback loop for obtaining sufficient BDNF levels necessary for various TrkB signaling-dependent physiological outcomes in neurons.
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14
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The N-Terminus of the Floral Arabidopsis TGA Transcription Factor PERIANTHIA Mediates Redox-Sensitive DNA-Binding. PLoS One 2016; 11:e0153810. [PMID: 27128442 PMCID: PMC4851370 DOI: 10.1371/journal.pone.0153810] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 04/04/2016] [Indexed: 12/19/2022] Open
Abstract
The Arabidopsis TGA transcription factor (TF) PERIANTHIA (PAN) regulates the formation of the floral organ primordia as revealed by the pan mutant forming an abnormal pentamerous arrangement of the outer three floral whorls. The Arabidopsis TGA bZIP TF family comprises 10 members, of which PAN and TGA9/10 control flower developmental processes and TGA1/2/5/6 participate in stress-responses. For the TGA1 protein it was shown that several cysteines can be redox-dependently modified. TGA proteins interact in the nucleus with land plant-specific glutaredoxins, which may alter their activities posttranslationally. Here, we investigated the DNA-binding of PAN to the AAGAAT motif under different redox-conditions. The AAGAAT motif is localized in the second intron of the floral homeotic regulator AGAMOUS (AG), which controls stamen and carpel development as well as floral determinacy. Whereas PAN protein binds to this regulatory cis-element under reducing conditions, the interaction is strongly reduced under oxidizing conditions in EMSA studies. The redox-sensitive DNA-binding is mediated via a special PAN N-terminus, which is not present in other Arabidopsis TGA TFs and comprises five cysteines. Two N-terminal PAN cysteines, Cys68 and Cys87, were shown to form a disulfide bridge and Cys340, localized in a C-terminal putative transactivation domain, can be S-glutathionylated. Comparative land plant analyses revealed that the AAGAAT motif exists in asterid and rosid plant species. TGA TFs with N-terminal extensions of variable length were identified in all analyzed seed plants. However, a PAN-like N-terminus exists only in the rosids and exclusively Brassicaceae homologs comprise four to five of the PAN N-terminal cysteines. Redox-dependent modifications of TGA cysteines are known to regulate the activity of stress-related TGA TFs. Here, we show that the N-terminal PAN cysteines participate in a redox-dependent control of the PAN interaction with a highly conserved regulatory AG cis-element, emphasizing the importance of redox-modifications in the regulation of flower developmental processes.
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15
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Contribution of transcription factor binding site motif variants to condition-specific gene expression patterns in budding yeast. PLoS One 2012; 7:e32274. [PMID: 22384202 PMCID: PMC3285675 DOI: 10.1371/journal.pone.0032274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 01/24/2012] [Indexed: 11/19/2022] Open
Abstract
It is now experimentally well known that variant sequences of a cis transcription factor binding site motif can contribute to differential regulation of genes. We characterize the relationship between motif variants and gene expression by analyzing expression microarray data and binding site predictions. To accomplish this, we statistically detect motif variants with effects that differ among environments. Such environmental specificity may be due to either affinity differences between variants or, more likely, differential interactions of TFs bound to these variants with cofactors, and with differential presence of cofactors across environments. We examine conservation of functional variants across four Saccharomyces species, and find that about a third of transcription factors have target genes that are differentially expressed in a condition-specific manner that is correlated with the nucleotide at variant motif positions. We find good correspondence between our results and some cases in the experimental literature (Reb1, Sum1, Mcm1, and Rap1). These results and growing consensus in the literature indicates that motif variants may often be functionally distinct, that this may be observed in genomic data, and that variants play an important role in condition-specific gene regulation.
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16
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Seldeen KL, Deegan BJ, Bhat V, Mikles DC, McDonald CB, Farooq A. Energetic coupling along an allosteric communication channel drives the binding of Jun-Fos heterodimeric transcription factor to DNA. FEBS J 2011; 278:2090-104. [PMID: 21496208 DOI: 10.1111/j.1742-4658.2011.08124.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Although allostery plays a central role in driving protein-DNA interactions, the physical basis of such cooperative behavior remains poorly understood. In the present study, using isothermal titration calorimetry in conjunction with site-directed mutagenesis, we provide evidence that an intricate network of energetically-coupled residues within the basic regions of the Jun-Fos heterodimeric transcription factor accounts for its allosteric binding to DNA. Remarkably, energetic coupling is prevalent in residues that are both close in space, as well as residues distant in space, implicating the role of both short- and long-range cooperative interactions in driving the assembly of this key protein-DNA interaction. Unexpectedly, many of the energetically-coupled residues involved in orchestrating such a cooperative network of interactions are poorly conserved across other members of the basic zipper family, emphasizing the importance of basic residues in dictating the specificity of basic zipper-DNA interactions. Collectively, our thermodynamic analysis maps an allosteric communication channel driving a key protein-DNA interaction central to cellular functions in health and disease.
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Affiliation(s)
- Kenneth L Seldeen
- Department of Biochemistry & Molecular Biology and USylvester Braman Family Breast Cancer Institute, Leonard Miller School of Medicine, University of Miami, Miami, FL 33136, USA
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17
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Davies JS, Klein DC, Carter DA. Selective genomic targeting by FRA-2/FOSL2 transcription factor: regulation of the Rgs4 gene is mediated by a variant activator protein 1 (AP-1) promoter sequence/CREB-binding protein (CBP) mechanism. J Biol Chem 2011; 286:15227-39. [PMID: 21367864 PMCID: PMC3083148 DOI: 10.1074/jbc.m110.201996] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 01/12/2011] [Indexed: 01/21/2023] Open
Abstract
FRA-2/FOSL2 is a basic region-leucine zipper motif transcription factor that is widely expressed in mammalian tissues. The functional repertoire of this factor is unclear, partly due to a lack of knowledge of genomic sequences that are targeted. Here, we identified novel, functional FRA-2 targets across the genome through expression profile analysis in a knockdown transgenic rat. In this model, a nocturnal rhythm of pineal gland FRA-2 is suppressed by a genetically encoded, dominant negative mutant protein. Bioinformatic analysis of validated sets of FRA-2-regulated and -nonregulated genes revealed that the FRA-2 regulon is limited by genomic target selection rules that, in general, transcend core cis-sequence identity. However, one variant AP-1-related (AP-1R) sequence was common to a subset of regulated genes. The functional activity and protein binding partners of a candidate AP-1R sequence were determined for a novel FRA-2-repressed gene, Rgs4. FRA-2 protein preferentially associated with a proximal Rgs4 AP-1R sequence as demonstrated by ex vivo ChIP and in vitro EMSA analysis; moreover, transcriptional repression was blocked by mutation of the AP-1R sequence, whereas mutation of an upstream consensus AP-1 family sequence did not affect Rgs4 expression. Nocturnal changes in protein complexes at the Rgs4 AP-1R sequence are associated with FRA-2-dependent dismissal of the co-activator, CBP; this provides a mechanistic basis for Rgs4 gene repression. These studies have also provided functional insight into selective genomic targeting by FRA-2, highlighting discordance between predicted and actual targets. Future studies should address FRA-2-Rgs4 interactions in other systems, including the brain, where FRA-2 function is poorly understood.
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Affiliation(s)
- Jeff S. Davies
- From the School of Biosciences, Cardiff University, Cardiff CF10 3AX, Wales, United Kingdom and
| | - David C. Klein
- the Section on Neuroendocrinology, Program on Developmental Endocrinology and Genetics, NICHD, National Institutes of Health, Bethesda, Maryland 20892
| | - David A. Carter
- From the School of Biosciences, Cardiff University, Cardiff CF10 3AX, Wales, United Kingdom and
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18
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Genetic variations within the ERE motif modulate plasticity and energetics of binding of DNA to the ERα nuclear receptor. Arch Biochem Biophys 2011; 507:262-70. [PMID: 21216218 DOI: 10.1016/j.abb.2011.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 01/03/2011] [Accepted: 01/03/2011] [Indexed: 11/20/2022]
Abstract
Upon binding to estrogens, the ERα nuclear receptor acts as a transcription factor and mediates a multitude of cellular functions central to health and disease. Herein, using isothermal titration calorimetry (ITC) and circular dichroism (CD) in conjunction with molecular modeling (MM), we analyze the effect of symmetric introduction of single nucleotide variations within each half-site of the estrogen response element (ERE) on the binding of ERα nuclear receptor. Our data reveal that ERα exudes remarkable tolerance and binds to all genetic variants in the physiologically relevant nanomolar-micromolar range with the consensus ERE motif affording the highest affinity. We provide rationale for how genetic variations within the ERE motif may reduce its affinity for ERα by orders of magnitude at atomic level. Our data also suggest that the introduction of genetic variations within the ERE motif allows it to sample a much greater conformational space. Surprisingly, ERα displays no preference for binding to ERE variants with higher AT content, implying that any advantage due to DNA plasticity may be largely compensated by unfavorable entropic factors. Collectively, our study bears important consequences for how genetic variations within DNA promoter elements may fine-tune the physiological action of ERα and other nuclear receptors.
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19
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Falconer RJ, Collins BM. Survey of the year 2009: applications of isothermal titration calorimetry. J Mol Recognit 2010; 24:1-16. [DOI: 10.1002/jmr.1073] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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20
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Seldeen KL, McDonald CB, Deegan BJ, Bhat V, Farooq A. Dissecting the role of leucine zippers in the binding of bZIP domains of Jun transcription factor to DNA. Biochem Biophys Res Commun 2010; 394:1030-5. [PMID: 20331972 DOI: 10.1016/j.bbrc.2010.03.116] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Accepted: 03/17/2010] [Indexed: 10/19/2022]
Abstract
Leucine zippers, structural motifs typically comprised of five successive heptads of amino acids with a signature leucine at every seventh position, play a central role in the dimerization of bZIP family of transcription factors and their subsequent binding to the DNA promoter regions of target genes. Herein, using analytical laser scattering (ALS) in combination with isothermal titration calorimetry (ITC), we study the effect of successive C-terminal truncation of leucine zippers on the dimerization and energetics of binding of bZIP domains of Jun transcription factor to its DNA response element. Our data show that all five heptads are critical for the dimerization of bZIP domains and that the successive C-terminal truncation of residues leading up to each signature leucine significantly compromises the binding of bZIP domains to DNA. Taken together, our study provides novel insights into the energetic contributions of leucine zippers to the binding of bZIP domains of Jun transcription factor to DNA.
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Affiliation(s)
- Kenneth L Seldeen
- Department of Biochemistry & Molecular Biology and USylvester Braman Family Breast Cancer Institute, Leonard Miller School of Medicine, University of Miami, Miami, FL 33136, USA
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21
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Seldeen KL, McDonald CB, Deegan BJ, Bhat V, Farooq A. DNA plasticity is a key determinant of the energetics of binding of Jun-Fos heterodimeric transcription factor to genetic variants of TGACGTCA motif. Biochemistry 2010; 48:12213-22. [PMID: 19921846 DOI: 10.1021/bi901392k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The Jun-Fos heterodimeric transcription factor is a target of a diverse array of signaling cascades that initiate at the cell surface and converge in the nucleus and ultimately result in the expression of genes involved in a multitude of cellular processes central to health and disease. Here, using isothermal titration calorimetry in conjunction with circular dichroism, we report the effect of introducing single nucleotide variations within the TGACGTCA canonical motif on the binding of bZIP domains of Jun-Fos heterodimer to DNA. Our data reveal that the Jun-Fos heterodimer exhibits differential energetics in binding to such genetic variants in the physiologically relevant micromolar to submicromolar range with the TGACGTCA canonical motif affording the highest affinity. Although binding energetics are largely favored by enthalpic forces and accompanied by entropic penalty, neither the favorable enthalpy nor the unfavorable entropy correlates with the overall free energy of binding in agreement with the enthalpy-entropy compensation phenomenon widely observed in biological systems. However, a number of variants including the TGACGTCA canonical motif bind to the Jun-Fos heterodimer with high affinity through having overcome such enthalpy-entropy compensation barrier, arguing strongly that better understanding of the underlying invisible forces driving macromolecular interactions may be the key to future drug design. Our data also suggest that the Jun-Fos heterodimer has a preference for binding to TGACGTCA variants with higher AT content, implying that the DNA plasticity may be an important determinant of protein-DNA interactions. This notion is further corroborated by the observation that the introduction of genetic variations within the TGACGTCA motif allows it to sample a much greater conformational space. Taken together, these new findings further our understanding of the role of DNA sequence and conformation on protein-DNA interactions in thermodynamic terms.
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Affiliation(s)
- Kenneth L Seldeen
- Department of Biochemistry and Molecular Biology and USylvester Braman Family Breast Cancer Institute, Leonard Miller School of Medicine, University of Miami, Miami, Florida 33136, USA
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