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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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Novel insights on nucleopeptide binding: A spectroscopic and in silico investigation on the interaction of a thymine-bearing tetrapeptide with a homoadenine DNA. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.117975] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Liu L, Zhao J, Peng Y, Yang M, Zhang L, Jin X. miR-let-7a-5p Inhibits Invasion and Migration of Hepatoma Cells by Regulating BZW2 Expression. Onco Targets Ther 2020; 13:12269-12279. [PMID: 33273832 PMCID: PMC7708316 DOI: 10.2147/ott.s278954] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/28/2020] [Indexed: 12/17/2022] Open
Abstract
Purpose This study was performed to investigate the effect of miRNA let-7a-5p on the proliferation, invasion, and migration of human hepatoma cells as well as to determine BZW2 expression in these cells. Methods Western blotting and real-time quantitative polymerase chain reaction were used to detect changes in the expression of miRNA let-7a-5p and BZW2 protein and gene, respectively. A luciferase reporter gene assay was used to examine whether BZW2 is the target gene of miR-let-7a-5p. The effect of miR-let-7a-5p on the invasion, migration, and proliferation of human hepatoma Bel-7404 and HepG2 cells was determined using the transwell invasion assay, scratch test, and CCK-8 assay, respectively. Flow cytometry was used to assess the effect of miR-let-7a-5p and BZW2 expression on apoptosis of hepatoma cells. Results The luciferase reporter gene assay identified BZW2 as the target gene of miR-let-7a-5p. Moreover, increased expression of miR-let-7a-5p was found to significantly decrease BZW2 expression; inhibit proliferation, invasion, and migration; and promote apoptosis of hepatoma cells. Conclusion miR-let-7a-5p can inhibit proliferation, invasion, and migration as well as promote apoptosis of hepatoma cells by decreasing BZW2 expression.
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Affiliation(s)
- Ling Liu
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, People's Republic of China.,Key Laboratory of Nanobiological Technology of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Jinfeng Zhao
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, People's Republic of China.,Key Laboratory of Nanobiological Technology of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Ying Peng
- Department of International Joint Research Center of Minimally Invasive Endoscopic Technology Equipment and Standards, Xiangya Hospital, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Manyi Yang
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, People's Republic of China.,Key Laboratory of Nanobiological Technology of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Lihua Zhang
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, People's Republic of China.,Key Laboratory of Nanobiological Technology of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, Hunan 410008, People's Republic of China
| | - Xin Jin
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, People's Republic of China.,Key Laboratory of Nanobiological Technology of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, Hunan 410008, People's Republic of China
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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: 43] [Impact Index Per Article: 10.8] [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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5
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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: 146] [Impact Index Per Article: 29.2] [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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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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Vargas-Lara F, Starr FW, Douglas JF. Molecular rigidity and enthalpy-entropy compensation in DNA melting. SOFT MATTER 2017; 13:8309-8330. [PMID: 29057399 DOI: 10.1039/c7sm01220a] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Enthalpy-entropy compensation (EEC) is observed in diverse molecular binding processes of importance to living systems and manufacturing applications, but this widely occurring phenomenon is not sufficiently understood from a molecular physics standpoint. To gain insight into this fundamental problem, we focus on the melting of double-stranded DNA (dsDNA) since measurements exhibiting EEC are extensive for nucleic acid complexes and existing coarse-grained models of DNA allow us to explore the influence of changes in molecular parameters on the energetic parameters by using molecular dynamics simulations. Previous experimental and computational studies have indicated a correlation between EEC and changes in molecular rigidity in certain binding-unbinding processes, and, correspondingly, we estimate measures of DNA molecular rigidity under a wide range of conditions, along with resultant changes in the enthalpy and entropy of binding. In particular, we consider variations in dsDNA rigidity that arise from changes of intrinsic molecular rigidity such as varying the associative interaction strength between the DNA bases, the length of the DNA chains, and the bending stiffness of the individual DNA chains. We also consider extrinsic changes of molecular rigidity arising from the addition of polymer additives and geometrical confinement of DNA between parallel plates. All our computations confirm EEC and indicate that this phenomenon is indeed highly correlated with changes in molecular rigidity. However, two distinct patterns relating to how DNA rigidity influences the entropy of association emerge from our analysis. Increasing the intrinsic DNA rigidity increases the entropy of binding, but increases in molecular rigidity from external constraints decreases the entropy of binding. EEC arises in numerous synthetic and biological binding processes and we suggest that changes in molecular rigidity might provide a common origin of this ubiquitous phenomenon in the mutual binding and unbinding of complex molecules.
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Affiliation(s)
- Fernando Vargas-Lara
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
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Pan A, Kar T, Rakshit AK, Moulik SP. Enthalpy–Entropy Compensation (EEC) Effect: Decisive Role of Free Energy. J Phys Chem B 2016; 120:10531-10539. [DOI: 10.1021/acs.jpcb.6b05890] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Animesh Pan
- Centre for Surface Science, Department of Chemistry and ‡Indian Society for Surface Science & Technology, Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | - Tanmoy Kar
- Centre for Surface Science, Department of Chemistry and ‡Indian Society for Surface Science & Technology, Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | - Animesh K. Rakshit
- Centre for Surface Science, Department of Chemistry and ‡Indian Society for Surface Science & Technology, Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | - Satya P. Moulik
- Centre for Surface Science, Department of Chemistry and ‡Indian Society for Surface Science & Technology, Department of Chemistry, Jadavpur University, Kolkata 700032, India
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9
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De Jong AT. Effect of flanking bases on the DNA specificity of EmBP-1. Biochemistry 2013; 52:786-94. [PMID: 23305409 DOI: 10.1021/bi301404h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
EmBP-1 is a basic region leucine zipper (bZIP) protein found in many types of plants. In general, plant bZIP proteins bind selectively to DNA sequences containing ACGT core sequences with different immediate flanking nucleotides preferred by different proteins. I report that the distant flanking sequence also has a strong effect on the preference of EmBP-1 for internal bases and determine the residue governing this effect. EmBP-1 binds selectively to the 10 bp gcG-box palindrome GCCACGTGGC 18-fold more tightly than the gcC-box GTGACGTCAC, but when the outer flanking G/C residues were changed to A/T (i.e., ACCACGTGGT and ATGACGTCAT), an only 1.2-fold preference for G-box binding was observed. Analysis of a series of single-residue alanine mutants of EmBP-1 revealed that this effect is mediated by arginine 10. Mutation of this residue to alanine greatly reduces the affinity for the gcG-box while leaving the affinity for other sequences relatively unchanged. Partial retention of G-box specificity upon mutation of R10 to lysine indicates that the effect is reliant on the basic nature of the residue. Additional studies with other EmBP-1 protein mutants and with oligonucleotides containing the T/A and C/G flanking sequences demonstrate the complexity of the protein-DNA interaction and demonstrate that the mechanism of sequence selective DNA binding is highly dependent on the flanking sequence.
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Affiliation(s)
- Antonia T De Jong
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada.
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Movileanu L, Schiff EA. Entropy-enthalpy Compensation of Biomolecular Systems in Aqueous Phase: a Dry Perspective. MONATSHEFTE FUR CHEMIE 2012; 144:59-65. [PMID: 23976794 DOI: 10.1007/s00706-012-0839-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We survey thermodynamic measurements on processes involving biological macromolecules in aqueous solution, which illustrate well the ubiquitous phenomenon of entropy-enthalpy compensation. The processes include protein folding/unfolding and ligand binding/unbinding, with compensation temperatures varying by about 50 K around an average near 293 K. We show that incorporating both near-exact entropy-enthalpy compensation (due to solvent relaxation) and multi-excitation entropy (from vibrational quanta) leads to a compensation temperature in water of about 230 K. We illustrate a general procedure for subtracting solvent and environment-related terms to determine the bare Gibbs free energy changes of chemical processes.
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Affiliation(s)
- Liviu Movileanu
- Department of Physics, Syracuse University, Syracuse, New York USA
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11
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Starikov E, Nordén B. Entropy–enthalpy compensation as a fundamental concept and analysis tool for systematical experimental data. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2012.04.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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12
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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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