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Miranda A, Cucchiarini A, Esnault C, Andrau JC, Oliveira PA, Mergny JL, Cruz C. G-quadruplex forming motifs in the promoter region of the B-MYB proto-oncogene. Int J Biol Macromol 2024; 270:132244. [PMID: 38729459 DOI: 10.1016/j.ijbiomac.2024.132244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/10/2024] [Accepted: 05/07/2024] [Indexed: 05/12/2024]
Abstract
To combat cancer, a comprehensive understanding of the molecular mechanisms and behaviors involved in carcinogenesis is crucial, as tumorigenesis is a complex process influenced by various genetic events and disease hallmarks. The B-MYB gene encodes a transcription factor involved in cell cycle regulation, survival, and differentiation in normal cells. B-MYB can be transformed into an oncogene through mutations, and abnormal expression of B-MYB has been identified in various cancers, including lung cancer, and is associated with poor prognosis. Targeting this oncogene is a promising approach for anti-cancer drug design. B-MYB has been deemed undruggable in previous reports, necessitating the search for novel therapeutic options. In this study, we found that the B-MYB gene promoter contains several G/C rich motifs compatible with G-quadruplex (G4) formation. We investigated and validated the existence of G4 structures in the promoter region of B-MYB, first in vitro using a combination of bioinformatics, biophysical, and biochemical methods, then in cell with the recently developed G4access method.
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Affiliation(s)
- André Miranda
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal; Centre for Research and Technology of Agro-Environmental and Biological Sciences (CITAB), Inov4Agro, University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal
| | - Anne Cucchiarini
- Laboratoire d'Optique et Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91120 Palaiseau, France
| | - Cyril Esnault
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR, 5535 Montpellier, France
| | - Jean-Christophe Andrau
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR, 5535 Montpellier, France
| | - Paula A Oliveira
- Centre for Research and Technology of Agro-Environmental and Biological Sciences (CITAB), Inov4Agro, University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal
| | - Jean-Louis Mergny
- Laboratoire d'Optique et Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91120 Palaiseau, France.
| | - Carla Cruz
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal; Departamento de Química, Universidade da Beira Interior, Rua Marquês de Ávila e Bolama, 6201-001 Covilhã, Portugal.
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2
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De Rache A, Marquevielle J, Bouaziz S, Vialet B, Andreola ML, Mergny JL, Amrane S. Structure of a DNA G-quadruplex that Modulates SP1 Binding Sites Architecture in HIV-1 Promoter. J Mol Biol 2024; 436:168359. [PMID: 37952768 DOI: 10.1016/j.jmb.2023.168359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/14/2023]
Abstract
Nucleic acid sequences containing guanine tracts are able to form non-canonical DNA or RNA structures known as G-quadruplexes (or G4s). These structures, based on the stacking of G-tetrads, are involved in various biological processes such as gene expression regulation. Here, we investigated a G4 forming sequence, HIVpro2, derived from the HIV-1 promoter. This motif is located 60 nucleotides upstream of the proviral Transcription Starting Site (TSS) and overlaps with two SP1 transcription factor binding sites. Using NMR spectroscopy, we determined that HIVpro2 forms a hybrid type G4 structure with a core that is interrupted by a single nucleotide bulge. An additional reverse-Hoogsteen AT base pair is stacked on top of the tetrad. SP1 transcription factor is known to regulate transcription activity of many genes through the recognition of Guanine-rich duplex motifs. Here, the formation of HIVpro2 G4 may modulate SP1 binding sites architecture by competing with the formation of the canonical duplex structure. Such DNA structural switch potentially participates to the regulation of viral transcription and may also interfere with HIV-1 reactivation or viral latency.
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Affiliation(s)
- Aurore De Rache
- Université de Bordeaux, Bordeaux, France; ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, Bordeaux, France; Department of Chemistry, U. Namur, 61 rue de Bruxelles, B5000 Namur, Belgium
| | - Julien Marquevielle
- Université de Bordeaux, Bordeaux, France; ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, Bordeaux, France
| | | | - Brune Vialet
- Université de Bordeaux, Bordeaux, France; ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, Bordeaux, France
| | - Marie-Line Andreola
- Université de Bordeaux, Bordeaux, France; MFP Laboratory, UMR5234, CNRS, Bordeaux, France
| | - Jean-Louis Mergny
- Laboratoire d'Optique & Biosciences, École Polytechnique, CNRS, Inserm, Institut Polytechnique de Paris, 91120 Palaiseau, France
| | - Samir Amrane
- Université de Bordeaux, Bordeaux, France; ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, Bordeaux, France.
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3
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Lorenzatti A, Piga EJ, Gismondi M, Binolfi A, Margarit E, Calcaterra N, Armas P. Genetic variations in G-quadruplex forming sequences affect the transcription of human disease-related genes. Nucleic Acids Res 2023; 51:12124-12139. [PMID: 37930868 PMCID: PMC10711447 DOI: 10.1093/nar/gkad948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/22/2023] [Accepted: 10/12/2023] [Indexed: 11/08/2023] Open
Abstract
Guanine-rich DNA strands can fold into non-canonical four-stranded secondary structures named G-quadruplexes (G4s). G4s folded in proximal promoter regions (PPR) are associated either with positive or negative transcriptional regulation. Given that single nucleotide variants (SNVs) affecting G4 folding (G4-Vars) may alter gene transcription, and that SNVs are associated with the human diseases' onset, we undertook a novel comprehensive study of the G4-Vars genome-wide (G4-variome) to find disease-associated G4-Vars located into PPRs. We developed a bioinformatics strategy to find disease-related SNVs located into PPRs simultaneously overlapping with putative G4-forming sequences (PQSs). We studied five G4-Vars disturbing in vitro the folding and stability of the G4s located into PPRs, which had been formerly associated with sporadic Alzheimer's disease (GRIN2B), a severe familiar coagulopathy (F7), atopic dermatitis (CSF2), myocardial infarction (SIRT1) and deafness (LHFPL5). Results obtained in cultured cells for these five G4-Vars suggest that the changes in the G4s affect the transcription, potentially contributing to the development of the mentioned diseases. Collectively, data reinforce the general idea that G4-Vars may impact on the different susceptibilities to human genetic diseases' onset, and could be novel targets for diagnosis and drug design in precision medicine.
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Affiliation(s)
- Agustín Lorenzatti
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, Rosario S2000EZP, Santa Fe, Argentina
| | - Ernesto J Piga
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, Rosario S2000EZP, Santa Fe, Argentina
| | - Mauro Gismondi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Suipacha 531, Rosario, Santa Fe, Argentina
| | - Andrés Binolfi
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, Rosario S2000EZP, Santa Fe, Argentina
- Plataforma Argentina de Biología Estructural y Metabolómica (PLABEM), Ocampo y Esmeralda, Rosario S200EZP, Santa Fe, Argentina
| | - Ezequiel Margarit
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Suipacha 531, Rosario, Santa Fe, Argentina
| | - Nora B Calcaterra
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, Rosario S2000EZP, Santa Fe, Argentina
| | - Pablo Armas
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, Rosario S2000EZP, Santa Fe, Argentina
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Balasooriya GI, Wee TL, Spector DL. A sub-set of guanine- and cytosine-rich genes are actively transcribed at the nuclear Lamin B1 region. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.28.564411. [PMID: 37961255 PMCID: PMC10634887 DOI: 10.1101/2023.10.28.564411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Chromatin organization in the mammalian cell nucleus plays a vital role in the regulation of gene expression. The lamina-associated domain at the inner nuclear membrane has been proposed to harbor heterochromatin, while the nuclear interior has been shown to contain most of the euchromatin. Here, we show that a sub-set of actively transcribing genes, marked by RNA Pol II pSer2, are associated with Lamin B1 at the inner nuclear envelop in mESCs and the number of genes proportionally increases upon in vitro differentiation of mESC to olfactory precursor cells. These nuclear periphery-associated actively transcribing genes primarily represent housekeeping genes, and their gene bodies are significantly enriched with guanine and cytosine compared to genes actively transcribed at the nuclear interior. We found the promoters of these genes to also be significantly enriched with guanine and to be predominantly regulated by zinc finger protein transcription factors. We provide evidence supporting the emerging notion that the Lamin B1 region is not solely transcriptionally silent.
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Duy DL, Kim N. Yeast transcription factor Msn2 binds to G4 DNA. Nucleic Acids Res 2023; 51:9643-9657. [PMID: 37615577 PMCID: PMC10570036 DOI: 10.1093/nar/gkad684] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 08/03/2023] [Accepted: 08/15/2023] [Indexed: 08/25/2023] Open
Abstract
Sequences capable of forming quadruplex or G4 DNA are prevalent in the promoter regions. The transformation from canonical to non-canonical secondary structure apparently regulates transcription of a number of human genes. In the budding yeast Saccharomyces cerevisiae, we identified 37 genes with a G4 motif in the promoters including 20 genes that contain stress response element (STRE) overlapping a G4 motif. STRE is the binding site of stress response regulators Msn2 and Msn4, transcription factors belonging to the C2H2 zinc-finger protein family. We show here that Msn2 binds directly to the G4 DNA structure through its zinc-finger domain with a dissociation constant similar to that of STRE-binding and that, in a stress condition, Msn2 is enriched at G4 DNA-forming loci in the yeast genome. For a large fraction of genes with G4/STRE-containing promoters, treating with G4-ligands led to significant elevations in transcription levels. Such transcriptional elevation was greatly diminished in a msn2Δ msn4Δ background and was partly muted when the G4 motif was disrupted. Taken together, our data suggest that G4 DNA could be an alternative binding site of Msn2 in addition to STRE, and that G4 DNA formation could be an important element of transcriptional regulation in yeast.
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Affiliation(s)
- Duong Long Duy
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Nayun Kim
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX 77030, USA
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6
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Zhang ZH, Qian SH, Wei D, Chen ZX. In vivo dynamics and regulation of DNA G-quadruplex structures in mammals. Cell Biosci 2023; 13:117. [PMID: 37381029 DOI: 10.1186/s13578-023-01074-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 06/19/2023] [Indexed: 06/30/2023] Open
Abstract
G-quadruplex (G4) is a four-stranded helical DNA secondary structure formed by guanine-rich sequence folding, and G4 has been computationally predicted to exist in a wide range of species. Substantial evidence has supported the formation of endogenous G4 (eG4) in living cells and revealed its regulatory dynamics and critical roles in several important biological processes, making eG4 a regulator of gene expression perturbation and a promising therapeutic target in disease biology. Here, we reviewed the methods for prediction of potential G4 sequences (PQS) and detection of eG4s. We also highlighted the factors affecting the dynamics of eG4s and the effects of eG4 dynamics. Finally, we discussed the future applications of eG4 dynamics in disease therapy.
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Affiliation(s)
- Ze-Hao Zhang
- Hubei Hongshan Laboratory, College of Life Science and Technology, College of Biomedicine and Health, Interdisciplinary Sciences Institute, Huazhong Agricultural University, Wuhan, 430070, China
| | - Sheng Hu Qian
- Hubei Hongshan Laboratory, College of Life Science and Technology, College of Biomedicine and Health, Interdisciplinary Sciences Institute, Huazhong Agricultural University, Wuhan, 430070, China
| | - Dengguo Wei
- College of Science, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhen-Xia Chen
- Hubei Hongshan Laboratory, College of Life Science and Technology, College of Biomedicine and Health, Interdisciplinary Sciences Institute, Huazhong Agricultural University, Wuhan, 430070, China.
- Shenzhen Institute of Nutrition and Health, Huazhong Agricultural University, Shenzhen, 518000, China.
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China.
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7
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Wu S, Jiang L, Lei L, Fu C, Huang J, Hu Y, Dong Y, Chen J, Zeng Q. Crosstalk between G-quadruplex and ROS. Cell Death Dis 2023; 14:37. [PMID: 36653351 PMCID: PMC9849334 DOI: 10.1038/s41419-023-05562-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 12/25/2022] [Accepted: 01/05/2023] [Indexed: 01/19/2023]
Abstract
The excessive production of reactive oxygen species (ROS) can lead to single nucleic acid base damage, DNA strand breakage, inter- and intra-strand cross-linking of nucleic acids, and protein-DNA cross-linking involved in the pathogenesis of cancer, neurodegenerative diseases, and aging. G-quadruplex (G4) is a stacked nucleic acid structure that is ubiquitous across regulatory regions of multiple genes. Abnormal formation and destruction of G4s due to multiple factors, including cations, helicases, transcription factors (TFs), G4-binding proteins, and epigenetic modifications, affect gene replication, transcription, translation, and epigenetic regulation. Due to the lower redox potential of G-rich sequences and unique structural characteristics, G4s are highly susceptible to oxidative damage. Additionally, the formation, stability, and biological regulatory role of G4s are affected by ROS. G4s are involved in regulating gene transcription, translation, and telomere length maintenance, and are therefore key players in age-related degeneration. Furthermore, G4s also mediate the antioxidant process by forming stress granules and activating Nrf2, which is suggestive of their involvement in developing ROS-related diseases. In this review, we have summarized the crosstalk between ROS and G4s, and the possible regulatory mechanisms through which G4s play roles in aging and age-related diseases.
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Affiliation(s)
- Songjiang Wu
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Ling Jiang
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Li Lei
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Chuhan Fu
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Jinhua Huang
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Yibo Hu
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Yumeng Dong
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Jing Chen
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China.
| | - Qinghai Zeng
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China.
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Vinayagamurthy S, Bagri S, Mergny JL, Chowdhury S. Telomeres expand sphere of influence: emerging molecular impact of telomeres in non-telomeric functions. Trends Genet 2023; 39:59-73. [PMID: 36404192 PMCID: PMC7614491 DOI: 10.1016/j.tig.2022.10.002] [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: 06/05/2022] [Revised: 09/12/2022] [Accepted: 10/26/2022] [Indexed: 11/18/2022]
Abstract
Although the impact of telomeres on physiology stands well established, a question remains: how do telomeres impact cellular functions at a molecular level? This is because current understanding limits the influence of telomeres to adjacent subtelomeric regions despite the wide-ranging impact of telomeres. Emerging work in two distinct aspects offers opportunities to bridge this gap. First, telomere-binding factors were found with non-telomeric functions. Second, locally induced DNA secondary structures called G-quadruplexes are notably abundant in telomeres, and gene regulatory regions genome wide. Many telomeric factors bind to G-quadruplexes for non-telomeric functions. Here we discuss a more general model of how telomeres impact the non-telomeric genome - through factors that associate at telomeres and genome wide - and influence cell-intrinsic functions, particularly aging, cancer, and pluripotency.
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Affiliation(s)
- Soujanya Vinayagamurthy
- Integrative and Functional Biology Unit, CSIR Institute of Genomics and Integrative Biology, New Delhi 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sulochana Bagri
- Integrative and Functional Biology Unit, CSIR Institute of Genomics and Integrative Biology, New Delhi 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Jean-Louis Mergny
- Institute of Biophysics of the CAS, v.v.i. Královopolská 135, 612 65 Brno, Czech Republic; Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Shantanu Chowdhury
- Integrative and Functional Biology Unit, CSIR Institute of Genomics and Integrative Biology, New Delhi 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India; GNR Knowledge Centre for Genome and Informatics, CSIR Institute of Genomics and Integrative Biology, New Delhi 110025, India.
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9
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Yang R, Zuo L, Ma H, Zhou Y, Zhou P, Wang L, Wang M, Latif M, Kong L. Downregulation of nc886 contributes to prostate cancer cell invasion and TGFβ1-induced EMT. Genes Dis 2022; 9:1086-1098. [PMID: 35685460 PMCID: PMC9170576 DOI: 10.1016/j.gendis.2020.12.010] [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: 06/22/2020] [Revised: 12/09/2020] [Accepted: 12/24/2020] [Indexed: 11/16/2022] Open
Abstract
Epithelial-to-mesenchymal transition (EMT) activation is important in cancer progression and metastasis. Evidence indicates that nc886 is a representative Pol III gene that processes microRNA products via Dicer and further downregulates its target gene transforming growth factor- β1 (TGF-β1), which is the most prominent inducer of EMT in prostate cancer (PC). Consistent with the previous literature, we found that nc886 downregulation was strongly associated with metastatic behavior and showed worse outcomes in PC patients. However, little is known about the association between nc886 and the EMT signaling pathway. We developed a PC cell model with stable overexpression of nc886 and found that nc886 changed cellular morphology and drove MET. The underlying mechanism may be related to its promotion of SNAIL protein degradation via ubiquitination, but not to its neighboring genes, TGFβ-induced protein (TGFBI) and SMAD5, which are Pol II-transcribed. TGF-β1 also override nc886 promotion of MET via transient suppression the transcription of nc886, promotion of TGFBI or increase in SMAD5 phosphorylation. Both nc886 inhibition and TGFBI activation occur regardless of their methylation status. The literature suggests that MYC inhibition by TGF-β1 is attributed to nc886 downregulation. We incidentally identified MYC-associated zinc finger protein (MAZ) as a suppressive transcription factor of TGFBI, which is controlled by TGF-β1. We elucidate a new mechanism of TGF-β1 differential control of Pol II and the transcription of its neighboring Pol III gene and identify a new EMT unit consisting of nc886 and its neighboring genes.
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Affiliation(s)
- Ronghui Yang
- Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing 100069, PR China
| | - Lingkun Zuo
- Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing 100069, PR China
| | - Hui Ma
- Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing 100069, PR China
| | - Ying Zhou
- Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing 100069, PR China
| | - Ping Zhou
- Biomedical Engineering Institute of Capital Medical University, Capital Medical University, Beijing 100069, PR China
| | - Liyong Wang
- Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing 100069, PR China
| | - Miao Wang
- Department of Pathology, Beijing Friendship Hospital, The Second Clinical Medical College of Capital Medical University, Beijing 100050, PR China
| | - Mahrukh Latif
- Department of Nuclear Medicine, Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050010, PR China
| | - Lu Kong
- Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing 100069, PR China
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10
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Feng Y, Tao S, Zhang P, Sperti FR, Liu G, Cheng X, Zhang T, Yu H, Wang XE, Chen C, Monchaud D, Zhang W. Epigenomic features of DNA G-quadruplexes and their roles in regulating rice gene transcription. PLANT PHYSIOLOGY 2022; 188:1632-1648. [PMID: 34893906 PMCID: PMC8896617 DOI: 10.1093/plphys/kiab566] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 11/04/2021] [Indexed: 06/01/2023]
Abstract
A DNA G-quadruplex (G4) is a non-canonical four-stranded nucleic acid structure involved in many biological processes in mammals. The current knowledge on plant DNA G4s, however, is limited; whether and how DNA G4s impact gene expression in plants is still largely unknown. Here, we applied a protocol referred to as BG4-DNA-IP-seq followed by a comprehensive characterization of DNA G4s in rice (Oryza sativa L.); we next integrated dG4s (experimentally detectable G4s) with existing omics data and found that dG4s exhibited differential DNA methylation between transposable element (TE) and non-TE genes. dG4 regions displayed genic-dependent enrichment of epigenomic signatures; finally, we showed that these sites displayed a positive association with expression of DNA G4-containing genes when located at promoters, and a negative association when located in the gene body, suggesting localization-dependent promotional/repressive roles of DNA G4s in regulating gene transcription. This study reveals interrelations between DNA G4s and epigenomic signatures, as well as implicates DNA G4s in modulating gene transcription in rice. Our study provides valuable resources for the functional characterization or bioengineering of some of key DNA G4s in rice.
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Affiliation(s)
- Yilong Feng
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JCIC-MCP, CIC-MCP, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, China
| | - Shentong Tao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JCIC-MCP, CIC-MCP, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, China
| | - Pengyue Zhang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JCIC-MCP, CIC-MCP, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, China
| | - Francesco Rota Sperti
- Institut de Chimie Moleculaire, ICMUB, CNRS UMR 6302, UBFC Dijon, 21078 Dijon, France
| | - Guanqing Liu
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Crop Genetics and Physiology and Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Xuejiao Cheng
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JCIC-MCP, CIC-MCP, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, China
| | - Tao Zhang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Crop Genetics and Physiology and Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Hengxiu Yu
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, China
| | - Xiu-e Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JCIC-MCP, CIC-MCP, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, China
| | - Caiyan Chen
- Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan 410125, China
| | - David Monchaud
- Institut de Chimie Moleculaire, ICMUB, CNRS UMR 6302, UBFC Dijon, 21078 Dijon, France
| | - Wenli Zhang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JCIC-MCP, CIC-MCP, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu 210095, China
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11
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Kretzmann JA, Irving KL, Smith NM, Evans CW. Modulating gene expression in breast cancer via DNA secondary structure and the CRISPR toolbox. NAR Cancer 2022; 3:zcab048. [PMID: 34988459 PMCID: PMC8693572 DOI: 10.1093/narcan/zcab048] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/26/2021] [Accepted: 12/01/2021] [Indexed: 12/11/2022] Open
Abstract
Breast cancer is the most commonly diagnosed malignancy in women, and while the survival prognosis of patients with early-stage, non-metastatic disease is ∼75%, recurrence poses a significant risk and advanced and/or metastatic breast cancer is incurable. A distinctive feature of advanced breast cancer is an unstable genome and altered gene expression patterns that result in disease heterogeneity. Transcription factors represent a unique therapeutic opportunity in breast cancer, since they are known regulators of gene expression, including gene expression involved in differentiation and cell death, which are themselves often mutated or dysregulated in cancer. While transcription factors have traditionally been viewed as 'undruggable', progress has been made in the development of small-molecule therapeutics to target relevant protein-protein, protein-DNA and enzymatic active sites, with varying levels of success. However, non-traditional approaches such as epigenetic editing, transcriptional control via CRISPR/dCas9 systems, and gene regulation through non-canonical nucleic acid secondary structures represent new directions yet to be fully explored. Here, we discuss these new approaches and current limitations in light of new therapeutic opportunities for breast cancers.
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Affiliation(s)
- Jessica A Kretzmann
- Laboratory for Biomolecular Nanotechnology, Department of Physics, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
| | - Kelly L Irving
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia
| | - Nicole M Smith
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia
| | - Cameron W Evans
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia
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12
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Jara-Espejo M, Hawkins MTR, Fogalli GB, Line SRP. Folding Stability of Pax9 Intronic G-Quadruplex Correlates with Relative Molar Size in Eutherians. Mol Biol Evol 2021; 38:1860-1873. [PMID: 33355664 PMCID: PMC8097303 DOI: 10.1093/molbev/msaa331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Eutherian dentition has been the focus of a great deal of studies in the areas of evolution, development, and genomics. The development of molar teeth is regulated by an antero-to-posterior cascade mechanism of activators and inhibitors molecules, where the relative sizes of the second (M2) and third (M3) molars are dependent of the inhibitory influence of the first molar (M1). Higher activator/inhibitor ratios will result in higher M2/M1 or M3/M1. Pax9 has been shown to play a key role in tooth development. We have previously shown that a G-quadruplex in the first intron of Pax9 can modulate the splicing efficiency. Using a sliding window approach with we analyzed the association of the folding energy (Mfe) of the Pax9 first intron with the relative molar sizes in 42 mammalian species, representing 9 orders. The Mfe of two regions located in the first intron of Pax9 were shown to be significantly associated with the M2/M1 and M3/M1 areas and mesiodistal lengths. The first region is located at the intron beginning and can fold into a stable G4 structure, whereas the second is downstream the G4 and 265 bp from intron start. Across species, the first intron of Pax9 varied in G-quadruplex structural stability. The correlations were further increased when the Mfe of the two sequences were added. Our results indicate that this region has a role in the evolution of the mammalian dental pattern by influencing the relative size of the molars.
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Affiliation(s)
- Manuel Jara-Espejo
- Department of Biosciences, Piracicaba Dental School, University of Campinas, Brazil
| | - Melissa T R Hawkins
- Division of Mammals, Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
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13
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Promoter G-quadruplex favours epigenetic reprogramming-induced atypical expression of ZEB1 in cancer cells. Biochim Biophys Acta Gen Subj 2021; 1865:129899. [PMID: 33930476 DOI: 10.1016/j.bbagen.2021.129899] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 03/17/2021] [Accepted: 04/06/2021] [Indexed: 12/18/2022]
Abstract
BACKGROUND Aberrant expression of Zinc-finger E-box binding homeobox 1 (ZEB1), which remains repressed in normal cells, is frequently associated with cancer aggressiveness. However, transcriptional mechanism underlying such atypical ZEB1 expression in cancer is not yet well-understood. METHODS ZEB1 promoter G-quadruplexes were studied and modeled extensively using circular dichroism, fluorescence spectroscopy, ITC and DMS protection assay. Luciferase assay, qPCR, FAIRE, ChIP, western blotting, confocal microscopy was used to access the regulation of ZEB1 transcription. RESULTS Our study unravels the occupancy of nucleolin to ZEB1 promoter as a crucial determinant which facilitates the binding of SP1 transcription factor to chromatin, by locally remodelling the region. SP1, subsequently, recruits P300 acetyl transferase leading to enriched acetyl-histone H3 at promoter and activates ZEB1 transcription. ZEB1 promoter analysis identifies presence of four putative G-quadruplex (G4) forming motifs within 700 bp of TSS; each quadruplex is characterized structurally in details with an array of biophysical techniques. Surprisingly, stabilization of G4 with cationic porphyrin TMPyP4 represses its transcription and eventually impedes cell invasiveness. CONCLUSIONS TMPyP4 binding to a selected G4 motif (5' -534/-511-3' from TSS), where nucleolin/SP1/P300 co-occupies, prevents the association of nucleolin which consequently hinders SP1 binding, leading to chromatin compactness and transcriptional repression. GENERAL SIGNIFICANCE Our findings demonstrate an epigenetic mechanism of ZEB1 reactivation where dynamic occupancy of transcription regulators encompassing a G4 motif is crucial and thus, small molecule induced G-quadruplex stabilization may act as a potential molecular switch to turn-off gene expression.
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14
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Sengupta A, Roy SS, Chowdhury S. Non-duplex G-Quadruplex DNA Structure: A Developing Story from Predicted Sequences to DNA Structure-Dependent Epigenetics and Beyond. Acc Chem Res 2021; 54:46-56. [PMID: 33347280 DOI: 10.1021/acs.accounts.0c00431] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The story of the non-duplex DNA form known as the G-quadruplex (G4) has traversed a winding path. From initial skepticism followed by debate to a surge in interest, the G4 story intertwines many threads. Starting with computational predictions of a gene regulatory role, which now include epigenetic functions, our group was involved in many of these advances along with many other laboratories. Following a brief background, set in the latter half of the last century when the concept of the G4 as a structure took ground, here we account the developments. This is through a lens that though focused on our groups' research presents work from many other groups that played significant roles. Together these provide a broad perspective to the G4 story. Initially we were intrigued on seeing potential G4 (pG4)-forming sequences, then known to be found primarily at the telomeres and immunoglobin switch regions, occurring throughout the genome and being particularly prevalent in promoters of bacteria. We further observed that pG4s were not only prevalent but also conserved through evolution in promoters of human, chimpanzee, mouse and rat genomes. This was between 2005 and 2007. Encouraged by these partly and partly in response to the view held by many that genome-wide presence of G4s were genomic "accidents", the focus shifted to seeking experimental evidence.In the next year, 2008, two independent findings showed promise. First, on treating human cancer cells with G4-binding ligands, we observed widespread change in gene expression. Second, our search for the missing G4-specific transcription factor, without which, importantly, G4s in promoters posed only half the story, yielded results. We determined how NM23-H2 (also known as NME2 or NDPK-B) interacts with G4s and how interaction of NM23-H2 with a G4 in the promoter of the oncogene c-myc was important for regulation of c-myc transcription. NM23-H2, and subsequently many other similar factors discovered by multiple groups, is possibly giving shape to what might be the "G4-transcriptome". Later, a close look at NM23-H2-G4 interaction in regulation of the human reverse transcriptase gene (hTERT) revealed the role of G4s in local epigenetic modifications. Meanwhile work from others showed how G4s impact histone modifications following replication. Together these show the intrinsic role of DNA sequence, through formation of DNA structure, in epigenetics.More recent work, however, was waiting to reveal aspects that tend to bring forth a completely new understanding of G4s. We observed that the telomere-repeat-binding-factor-2 (TRF2), known canonically to be telomere-associated, binds extensively outside telomeres throughout the genome. Moreover, a large fraction of the non-telomeric TRF2 sites comprise G4s. Second, the extent of non-telomeric TRF2 binding at promoters was dependent on telomere length. Thereby TRF2-induced epigenetic gene regulation was telomere-dependent. Together these implicate underlying connections that show signs of addressing an intriguing unanswered question that takes us back to the beginning: Why are G4s prevalent in two distinct regions, the telomeres and gene promoters?
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Affiliation(s)
- Antara Sengupta
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Shuvra Shekhar Roy
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Shantanu Chowdhury
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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15
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Role of Poly [ADP-ribose] Polymerase 1 in Activating the Kirsten ras ( KRAS) Gene in Response to Oxidative Stress. Int J Mol Sci 2020; 21:ijms21176237. [PMID: 32872305 PMCID: PMC7504130 DOI: 10.3390/ijms21176237] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/21/2020] [Accepted: 08/23/2020] [Indexed: 12/12/2022] Open
Abstract
In pancreatic Panc-1 cancer cells, an increase of oxidative stress enhances the level of 7,8-dihydro-8-oxoguanine (8OG) more in the KRAS promoter region containing G4 motifs than in non-G4 motif G-rich genomic regions. We found that H2O2 stimulates the recruitment to the KRAS promoter of poly [ADP-ribose] polymerase 1 (PARP-1), which efficiently binds to local G4 structures. Upon binding to G4 DNA, PARP-1 undergoes auto PARylation and thus becomes negatively charged. In our view this should favor the recruitment to the KRAS promoter of MAZ and hnRNP A1, as these two nuclear factors, because of their isoelectric points >7, are cationic in nature under physiological conditions. This is indeed supported by pulldown assays which showed that PARP-1, MAZ, and hnRNP A1 form a multiprotein complex with an oligonucleotide mimicking the KRAS G4 structure. Our data suggest that an increase of oxidative stress in Panc-1 cells activates a ROS-G4-PARP-1 axis that stimulates the transcription of KRAS. This mechanism is confirmed by the finding that when PARP-1 is silenced by siRNA or auto PARylation is inhibited by Veliparib, the expression of KRAS is downregulated. When Panc-1 cells are treated with H2O2 instead, a strong up-regulation of KRAS transcription is observed.
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16
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Varshney D, Spiegel J, Zyner K, Tannahill D, Balasubramanian S. The regulation and functions of DNA and RNA G-quadruplexes. Nat Rev Mol Cell Biol 2020; 21:459-474. [PMID: 32313204 PMCID: PMC7115845 DOI: 10.1038/s41580-020-0236-x] [Citation(s) in RCA: 574] [Impact Index Per Article: 143.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2020] [Indexed: 02/06/2023]
Abstract
DNA and RNA can adopt various secondary structures. Four-stranded G-quadruplex (G4) structures form through self-recognition of guanines into stacked tetrads, and considerable biophysical and structural evidence exists for G4 formation in vitro. Computational studies and sequencing methods have revealed the prevalence of G4 sequence motifs at gene regulatory regions in various genomes, including in humans. Experiments using chemical, molecular and cell biology methods have demonstrated that G4s exist in chromatin DNA and in RNA, and have linked G4 formation with key biological processes ranging from transcription and translation to genome instability and cancer. In this Review, we first discuss the identification of G4s and evidence for their formation in cells using chemical biology, imaging and genomic technologies. We then discuss possible functions of DNA G4s and their interacting proteins, particularly in transcription, telomere biology and genome instability. Roles of RNA G4s in RNA biology, especially in translation, are also discussed. Furthermore, we consider the emerging relationships of G4s with chromatin and with RNA modifications. Finally, we discuss the connection between G4 formation and synthetic lethality in cancer cells, and recent progress towards considering G4s as therapeutic targets in human diseases.
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Affiliation(s)
- Dhaval Varshney
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - Jochen Spiegel
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - Katherine Zyner
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - David Tannahill
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - Shankar Balasubramanian
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK.
- Department of Chemistry, University of Cambridge, Cambridge, UK.
- School of Clinical Medicine, University of Cambridge, Cambridge, UK.
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17
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Hao W, Wang J, Zhang Y, Wang C, Xia L, Zhang W, Zafar M, Kang JY, Wang R, Ali Bohio A, Pan L, Zeng X, Wei M, Boldogh I, Ba X. Enzymatically inactive OGG1 binds to DNA and steers base excision repair toward gene transcription. FASEB J 2020; 34:7427-7441. [PMID: 32378256 PMCID: PMC7318607 DOI: 10.1096/fj.201902243r] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/19/2019] [Accepted: 03/17/2020] [Indexed: 12/11/2022]
Abstract
8‐Oxoguanine DNA glycosylase1 (OGG1)‐initiated base excision repair (BER) is the primary pathway to remove the pre‐mutagenic 8‐oxo‐7,8‐dihydroguanine (8‐oxoG) from DNA. Recent studies documented 8‐oxoG serves as an epigenetic‐like mark and OGG1 modulates gene expression in oxidatively stressed cells. For this new role of OGG1, two distinct mechanisms have been proposed: one is coupled to base excision, while the other only requires substrate binding of OGG1––both resulting in conformational adjustment in the adjacent DNA sequences providing access for transcription factors to their cis‐elements. The present study aimed to examine if BER activity of OGG1 is required for pro‐inflammatory gene expression. To this end, Ogg1/OGG1 knockout/depleted cells were transfected with constructs expressing wild‐type (wt) and repair‐deficient mutants of OGG1. OGG1's promoter enrichment, oxidative state, and gene expression were examined. Results showed that TNFα exposure increased levels of oxidatively modified cysteine(s) of wt OGG1 without impairing its association with promoter and facilitated gene expression. The excision deficient K249Q mutant was even a more potent activator of gene expression; whereas, mutant OGG1 with impaired substrate recognition/binding was not. These data suggested the interaction of OGG1 with its substrate at regulatory regions followed by conformational adjustment in the adjacent DNA is the primary mode to modulate inflammatory gene expression.
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Affiliation(s)
- Wenjing Hao
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Jing Wang
- Department of Respiratory Medicine, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Yuanhang Zhang
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Chenxin Wang
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Lan Xia
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Wenhe Zhang
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Muhammad Zafar
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Ju-Yong Kang
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,Faculty of Life Science, Kim Il Sung University, Pyongyang, DPRK
| | - Ruoxi Wang
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China.,Key Laboratory of Animal Resistance Biology of Shandong Province, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Ameer Ali Bohio
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Lang Pan
- School of Life Science, Northeast Normal University, Changchun, China.,Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Xianlu Zeng
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Min Wei
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Istvan Boldogh
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Xueqing Ba
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
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18
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Moruno-Manchon JF, Lejault P, Wang Y, McCauley B, Honarpisheh P, Morales Scheihing DA, Singh S, Dang W, Kim N, Urayama A, Zhu L, Monchaud D, McCullough LD, Tsvetkov AS. Small-molecule G-quadruplex stabilizers reveal a novel pathway of autophagy regulation in neurons. eLife 2020; 9:e52283. [PMID: 32043463 PMCID: PMC7012600 DOI: 10.7554/elife.52283] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 01/07/2020] [Indexed: 12/22/2022] Open
Abstract
Guanine-rich DNA sequences can fold into four-stranded G-quadruplex (G4-DNA) structures. G4-DNA regulates replication and transcription, at least in cancer cells. Here, we demonstrate that, in neurons, pharmacologically stabilizing G4-DNA with G4 ligands strongly downregulates the Atg7 gene. Atg7 is a critical gene for the initiation of autophagy that exhibits decreased transcription with aging. Using an in vitro assay, we show that a putative G-quadruplex-forming sequence (PQFS) in the first intron of the Atg7 gene folds into a G4. An antibody specific to G4-DNA and the G4-DNA-binding protein PC4 bind to the Atg7 PQFS. Mice treated with a G4 stabilizer develop memory deficits. Brain samples from aged mice contain G4-DNA structures that are absent in brain samples from young mice. Overexpressing the G4-DNA helicase Pif1 in neurons exposed to the G4 stabilizer improves phenotypes associated with G4-DNA stabilization. Our findings indicate that G4-DNA is a novel pathway for regulating autophagy in neurons.
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Affiliation(s)
- Jose F Moruno-Manchon
- Department of Neurobiology and AnatomyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Pauline Lejault
- Institut de Chimie Moléculaire (ICMUB), UBFC Dijon, CNRS UMR6302DijonFrance
| | - Yaoxuan Wang
- Department of Neurobiology and AnatomyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Brenna McCauley
- Huffington Center on AgingBaylor College of MedicineHoustonUnited States
| | - Pedram Honarpisheh
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
| | - Diego A Morales Scheihing
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Shivani Singh
- Department of Microbiology and Molecular GeneticsThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Weiwei Dang
- Huffington Center on AgingBaylor College of MedicineHoustonUnited States
| | - Nayun Kim
- Department of Microbiology and Molecular GeneticsThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Akihiko Urayama
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
| | - Liang Zhu
- Biostatistics and Epidemiology Research Design Core Center for Clinical and Translational SciencesThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- Department of Internal MedicineThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - David Monchaud
- Institut de Chimie Moléculaire (ICMUB), UBFC Dijon, CNRS UMR6302DijonFrance
| | - Louise D McCullough
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
| | - Andrey S Tsvetkov
- Department of Neurobiology and AnatomyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
- UTHealth Consortium on AgingThe University of Texas McGovern Medical School at HoustonHoustonUnited States
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19
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Mukherjee AK, Sharma S, Bagri S, Kutum R, Kumar P, Hussain A, Singh P, Saha D, Kar A, Dash D, Chowdhury S. Telomere repeat-binding factor 2 binds extensively to extra-telomeric G-quadruplexes and regulates the epigenetic status of several gene promoters. J Biol Chem 2019; 294:17709-17722. [PMID: 31575660 PMCID: PMC6879327 DOI: 10.1074/jbc.ra119.008687] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 09/18/2019] [Indexed: 12/22/2022] Open
Abstract
The role of the telomere repeat-binding factor 2 (TRF2) in telomere maintenance is well-established. However, recent findings suggest that TRF2 also functions outside telomeres, but relatively little is known about this function. Herein, using genome-wide ChIP-Seq assays of TRF2-bound chromatin from HT1080 fibrosarcoma cells, we identified thousands of TRF2-binding sites within the extra-telomeric genome. In light of this observation, we asked how TRF2 occupancy is organized within the genome. Interestingly, we found that extra-telomeric TRF2 sites throughout the genome are enriched in potential G-quadruplex-forming DNA sequences. Furthermore, we validated TRF2 occupancy at several promoter G-quadruplex motifs, which did adopt quadruplex forms in solution. TRF2 binding altered expression and the epigenetic state of several target promoters, indicated by histone modifications resulting in transcriptional repression of eight of nine genes investigated here. Furthermore, TRF2 occupancy and target gene expression were also sensitive to the well-known intracellular G-quadruplex-binding ligand 360A. Together, these results reveal an extensive genome-wide association of TRF2 outside telomeres and that it regulates gene expression in a G-quadruplex-dependent fashion.
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Affiliation(s)
- Ananda Kishore Mukherjee
- Integrative and Functional Biology Unit, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India.,Academy of Scientific and Innovative Research (AcSIR), Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Shalu Sharma
- Integrative and Functional Biology Unit, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India.,Academy of Scientific and Innovative Research (AcSIR), Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Sulochana Bagri
- Integrative and Functional Biology Unit, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Rintu Kutum
- Academy of Scientific and Innovative Research (AcSIR), Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India.,G.N.R. Knowledge Centre for Genome Informatics, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India.,CSIR Ayurgenomics Unit-TRISUTRA, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Pankaj Kumar
- Academy of Scientific and Innovative Research (AcSIR), Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India.,G.N.R. Knowledge Centre for Genome Informatics, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Asgar Hussain
- Academy of Scientific and Innovative Research (AcSIR), Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India.,G.N.R. Knowledge Centre for Genome Informatics, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Prateek Singh
- Academy of Scientific and Innovative Research (AcSIR), Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India.,G.N.R. Knowledge Centre for Genome Informatics, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Dhurjhoti Saha
- Integrative and Functional Biology Unit, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India.,Academy of Scientific and Innovative Research (AcSIR), Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Anirban Kar
- Integrative and Functional Biology Unit, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Debasis Dash
- Academy of Scientific and Innovative Research (AcSIR), Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India.,G.N.R. Knowledge Centre for Genome Informatics, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India.,CSIR Ayurgenomics Unit-TRISUTRA, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
| | - Shantanu Chowdhury
- Integrative and Functional Biology Unit, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India .,Academy of Scientific and Innovative Research (AcSIR), Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India.,G.N.R. Knowledge Centre for Genome Informatics, Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, New Delhi 110025, India
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20
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Jara-Espejo M, Line SR. DNA G-quadruplex stability, position and chromatin accessibility are associated with CpG island methylation. FEBS J 2019; 287:483-495. [PMID: 31532882 DOI: 10.1111/febs.15065] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/22/2019] [Accepted: 09/16/2019] [Indexed: 01/06/2023]
Abstract
CpG islands (CGI) are genomic regions associated with gene promoters and involved in gene expression regulation. Despite their high CpG content and unlike bulk genomic DNA methylation pattern, these regions are usually hypomethylated. So far, the mechanisms controlling the CGI methylation patterning remain unclear. G-quadruplex (G4) structures can inhibit DNA methyltransferases 1 enzymatic activity, leading to CGI hypomethylation. Our aim was to analyse the association of G4 forming sequences (G4FS) and CGI methylation as well as to determine the intrinsic and extrinsic characteristics of G4FS that may modulate this phenomenon. Using methylation data from human embryonic stem cells (hESCs) and three hESC-derived populations, we showed that hypomethylated CpGs located inside CGI (CGI/CpG) tend to be associated with highly stable G4FS (Minimum free energy ≤ -30 kcal·mol-1 ). The association of highly stable G4FS and hypomethylation tend to be stronger when these structures are located at shorter distances (~ < 150 bp) from GCI/CpGs, when G4FS and CpGs are located within open chromatin and G4FS are inside CGI. Moreover, this association is not strongly influenced by the CpG content of CGI. Conversely, highly methylated CGI/CpG tend to be associated with low stability G4FS. Although CpGs inside CGIs without a G4FS tend to be more methylated, high stability G4FS within CGI neighbourhood were associated with decreased methylation. In summary, our data indicate that G4FS may act as protective cis elements against CGI methylation, and this effect seems to be influenced by the G4FS folding potential, its presence within CGI, CpG distance from G4FS and chromatin accessibility.
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Affiliation(s)
- Manuel Jara-Espejo
- Department of Morphology, Piracicaba Dental School, University of Campinas - UNICAMP, Piracicaba, Brazil
| | - Sérgio Roberto Line
- Department of Morphology, Piracicaba Dental School, University of Campinas - UNICAMP, Piracicaba, Brazil
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21
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Saranathan N, Vivekanandan P. G-Quadruplexes: More Than Just a Kink in Microbial Genomes. Trends Microbiol 2019; 27:148-163. [PMID: 30224157 PMCID: PMC7127049 DOI: 10.1016/j.tim.2018.08.011] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/17/2018] [Accepted: 08/24/2018] [Indexed: 02/06/2023]
Abstract
G-quadruplexes (G4s) are noncanonical nucleic acid secondary structures formed by guanine-rich DNA and RNA sequences. In this review we aim to provide an overview of the biological roles of G4s in microbial genomes with emphasis on recent discoveries. G4s are enriched and conserved in the regulatory regions of microbes, including bacteria, fungi, and viruses. Importantly, G4s in hepatitis B virus (HBV) and hepatitis C virus (HCV) genomes modulate genes crucial for virus replication. Recent studies on Epstein-Barr virus (EBV) shed light on the role of G4s within the microbial transcripts as cis-acting regulatory signals that modulate translation and facilitate immune evasion. Furthermore, G4s in microbial genomes have been linked to radioresistance, antigenic variation, recombination, and latency. G4s in microbial genomes represent novel therapeutic targets for antimicrobial therapy.
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Affiliation(s)
- Nandhini Saranathan
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Perumal Vivekanandan
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India.
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22
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Qu X, Bian F, Guo Q, Ge Q, Sun Q, Huang X. Ligation-Rolling Circle Amplification on Quantum Dot-Encoded Microbeads for Detection of Multiplex G-Quadruplex-Forming Sequences. Anal Chem 2018; 90:12051-12058. [DOI: 10.1021/acs.analchem.8b02820] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Xiaojun Qu
- State Key Laboratory of Bioelectronics, National Demonstration Center for Experimental Biomedical Engineering Education, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China
| | - Feika Bian
- State Key Laboratory of Bioelectronics, National Demonstration Center for Experimental Biomedical Engineering Education, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China
| | - Qingsheng Guo
- State Key Laboratory of Bioelectronics, National Demonstration Center for Experimental Biomedical Engineering Education, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China
| | - Qinyu Ge
- State Key Laboratory of Bioelectronics, National Demonstration Center for Experimental Biomedical Engineering Education, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China
| | - Qingjiang Sun
- State Key Laboratory of Bioelectronics, National Demonstration Center for Experimental Biomedical Engineering Education, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China
| | - Xuebin Huang
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
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23
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Mandal K, Bader SL, Kumar P, Malakar D, Campbell DS, Pradhan BS, Sarkar RK, Wadhwa N, Sensharma S, Jain V, Moritz RL, Majumdar SS. An integrated transcriptomics-guided genome-wide promoter analysis and next-generation proteomics approach to mine factor(s) regulating cellular differentiation. DNA Res 2018; 24:143-157. [PMID: 28065881 PMCID: PMC5397609 DOI: 10.1093/dnares/dsw057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/24/2016] [Indexed: 12/19/2022] Open
Abstract
Differential next-generation-omics approaches aid in the visualization of biological processes and pave the way for divulging important events and/or interactions leading to a functional output at cellular or systems level. To this end, we undertook an integrated Nextgen transcriptomics and proteomics approach to divulge differential gene expression of infant and pubertal rat Sertoli cells (Sc).Unlike, pubertal Sc, infant Sc are immature and fail to support spermatogenesis. We found exclusive association of 14 and 19 transcription factor binding sites to infantile and pubertal states of Sc, respectively, using differential transcriptomics-guided genome-wide computational analysis of relevant promoters employing 220 Positional Weight Matrices from the TRANSFAC database. Proteomic SWATH-MS analysis provided extensive quantification of nuclear and cytoplasmic protein fractions revealing 1,670 proteins differentially located between the nucleus and cytoplasm of infant Sc and 890 proteins differentially located within those of pubertal Sc. Based on our multi-omics approach, the transcription factor YY1 was identified as one of the lead candidates regulating differentiation of Sc.YY1 was found to have abundant binding sites on promoters of genes upregulated during puberty. To determine its significance, we generated transgenic rats with Sc specific knockdown of YY1 that led to compromised spermatogenesis.
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Affiliation(s)
- Kamal Mandal
- Cellular Endocrinology Laboratory, National Institute of Immunology, New Delhi, India
| | | | - Pankaj Kumar
- G.N.R. Knowledge Centre for Genome Informatics, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | | | | | - Bhola Shankar Pradhan
- Cellular Endocrinology Laboratory, National Institute of Immunology, New Delhi, India
| | - Rajesh K Sarkar
- Cellular Endocrinology Laboratory, National Institute of Immunology, New Delhi, India
| | - Neerja Wadhwa
- Cellular Endocrinology Laboratory, National Institute of Immunology, New Delhi, India
| | - Souvik Sensharma
- Cellular Endocrinology Laboratory, National Institute of Immunology, New Delhi, India
| | - Vaibhav Jain
- Next-Generation Sequencing Facility, National Institute of Immunology, New Delhi, India
| | | | - Subeer S Majumdar
- Cellular Endocrinology Laboratory, National Institute of Immunology, New Delhi, India.,National Institute of Animal Biotechnology, Miyapur, Hyderabad, India
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24
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Tsukakoshi K, Saito S, Yoshida W, Goto S, Ikebukuro K. CpG Methylation Changes G-Quadruplex Structures Derived from Gene Promoters and Interaction with VEGF and SP1. Molecules 2018; 23:molecules23040944. [PMID: 29670067 PMCID: PMC6017926 DOI: 10.3390/molecules23040944] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 04/13/2018] [Accepted: 04/15/2018] [Indexed: 12/14/2022] Open
Abstract
G-quadruplex (G4) is a DNA/RNA conformation that consists of two or more G-tetrads resulting from four-guanine bases connected by Hoogsteen-type hydrogen bonds, which is often found in the telomeres of chromatin, as well as in the promoter regions of genes. The function of G4 in the genomic DNA is being elucidated and some G4-protein interactions have been reported; these are believed to play a role in vital cellular functions. In this study, we focused on CpG methylation, a well-known epigenetic modification of the genomic DNA, especially found in the promoter regions. Although many G4-forming sequences within the genomic DNA harbor CpG sites, the relationship between CpG methylation and the binding properties of associated proteins remains unclear. We demonstrated that the binding ability of vascular endothelial growth factor (VEGF) G4 DNA to VEGF165 protein was significantly decreased by CpG methylation. We identified the binding activity of G4 DNA oligonucleotides derived from gene promoter regions to SP1, a transcription factor that interacts with a G4-forming DNA and is also altered by CpG methylation. The effect of methylation on binding affinity was accompanied by changes in G4 structure and/or topology. Therefore, this study suggested that CpG methylation might be involved in protein binding to G4-forming DNA segments for purposes of transcriptional regulation.
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Affiliation(s)
- Kaori Tsukakoshi
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan.
| | - Shiori Saito
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan.
| | - Wataru Yoshida
- School of Bioscience and Biotechnology, Tokyo University of Technology, 1404-1 Katakuramachi, Hachioji, Tokyo 192-0982, Japan.
| | - Shinichi Goto
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan.
| | - Kazunori Ikebukuro
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan.
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25
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Purohit G, Mukherjee AK, Sharma S, Chowdhury S. Extratelomeric Binding of the Telomere Binding Protein TRF2 at the PCGF3 Promoter Is G-Quadruplex Motif-Dependent. Biochemistry 2018; 57:2317-2324. [PMID: 29589913 DOI: 10.1021/acs.biochem.8b00019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Telomere repeat binding factor 2 (TRF2) is critical for the protection of chromosome ends. Mounting evidence suggests that TRF2 associates with extratelomeric sites and TRF2 functions may not be limited to telomeres. Here, we show that the PCGF3 promoter harbors a sequence capable of forming the DNA secondary structure G-quadruplex motif, which is required for binding of TRF2 at the PCGF3 promoter. We demonstrate that promoter binding by TRF2 mediates PCGF3 promoter activity, and both the N-terminal and C-terminal domains of TRF2 are necessary for promoter activity. Altogether, this shows for the first time that a telomere binding factor may regulate a component of the polycomb group of proteins.
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26
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Zamiri B, Mirceta M, Abu-Ghazalah R, Wold MS, Pearson CE, Macgregor RB. Stress-induced acidification may contribute to formation of unusual structures in C9orf72-repeats. Biochim Biophys Acta Gen Subj 2018; 1862:1482-1491. [PMID: 29550431 DOI: 10.1016/j.bbagen.2018.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 02/22/2018] [Accepted: 03/04/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Expansion of the C9orf72 hexanucleotide repeat (GGGGCC)n·(GGCCCC)n is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Both strands of the C9orf72 repeat have been shown to form unusual DNA and RNA structures that are thought to be involved in mutagenesis and/or pathogenesis. We previously showed that the C-rich DNA strands from the C9orf72 repeat can form four-stranded quadruplexes at neutral pH. The cytosine residues become protonated under slightly acidic pH (pH 4.5-6.2), facilitating the formation of intercalated i-motif structures. METHODS Using CD spectroscopy, UV melting, and gel electrophoresis, we demonstrate a pH-induced structural transition of the C-rich DNA strand of the C9orf72 repeat at pHs reported to exist in living cells under stress, including during neurodegeneration and cancer. RESULTS We show that the repeats with lengths of 4, 6, and 8 units, form intercalated quadruplex i-motifs at low pH (pH < 5) and monomolecular hairpins and monomolecular quadruplexes under neutral-basic conditions (pH ≥ 8). Furthermore, we show that the human replication protein A (RPA) binds to the G-rich and C-rich DNA strands under acidic conditions, suggesting that it can bind to i-motif structures. CONCLUSIONS In the proper sequence context, i-motif structures can form at pH values found in some cells in vivo. GENERAL SIGNIFICANCE DNA conformational plasticity exists over broad range of solution conditions.
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Affiliation(s)
- Bita Zamiri
- Graduate Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Mila Mirceta
- Program of Genetics & Genome Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada; Program of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A1, Canada
| | - Rashid Abu-Ghazalah
- W. Booth School of Engineering Technology Practice and Technology, McMaster University, Hamilton, Ontario L8S 0A3, Canada
| | - Marc S Wold
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Christopher E Pearson
- Program of Genetics & Genome Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada; Program of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A1, Canada
| | - Robert B Macgregor
- Graduate Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada.
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27
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16p11.2 transcription factor MAZ is a dosage-sensitive regulator of genitourinary development. Proc Natl Acad Sci U S A 2018; 115:E1849-E1858. [PMID: 29432158 DOI: 10.1073/pnas.1716092115] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Genitourinary (GU) birth defects are among the most common yet least studied congenital malformations. Congenital anomalies of the kidney and urinary tract (CAKUTs) have high morbidity and mortality rates and account for ∼30% of structural birth defects. Copy number variation (CNV) mapping revealed that 16p11.2 is a hotspot for GU development. The only gene covered collectively by all of the mapped GU-patient CNVs was MYC-associated zinc finger transcription factor (MAZ), and MAZ CNV frequency is enriched in nonsyndromic GU-abnormal patients. Knockdown of MAZ in HEK293 cells results in differential expression of several WNT morphogens required for normal GU development, including Wnt11 and Wnt4. MAZ knockdown also prevents efficient transition into S phase, affects transcription of cell-cycle regulators, and abrogates growth of human embryonic kidney cells. Murine Maz is ubiquitously expressed, and a CRISPR-Cas9 mouse model of Maz deletion results in perinatal lethality with survival rates dependent on Maz copy number. Homozygous loss of Maz results in high penetrance of CAKUTs, and Maz is haploinsufficient for normal bladder development. MAZ, once thought to be a simple housekeeping gene, encodes a dosage-sensitive transcription factor that regulates urogenital development and contributes to both nonsyndromic congenital malformations of the GU tract as well as the 16p11.2 phenotype.
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28
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Das RN, Chevret E, Desplat V, Rubio S, Mergny JL, Guillon J. Design, Synthesis and Biological Evaluation of New Substituted Diquinolinyl-Pyridine Ligands as Anticancer Agents by Targeting G-Quadruplex. Molecules 2017; 23:molecules23010081. [PMID: 29301210 PMCID: PMC6017375 DOI: 10.3390/molecules23010081] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 12/20/2017] [Accepted: 12/29/2017] [Indexed: 11/16/2022] Open
Abstract
G-quadruplexes (G4) are stacked non-canonical nucleic acid structures found in specific G-rich DNA or RNA sequences in the human genome. G4 structures are liable for various biological functions; transcription, translation, cell aging as well as diseases such as cancer. These structures are therefore considered as important targets for the development of anticancer agents. Small organic heterocyclic molecules are well known to target and stabilize G4 structures. In this article, we have designed and synthesized 2,6-di-(4-carbamoyl-2-quinolyl)pyridine derivatives and their ability to stabilize G4-structures have been determined through the FRET melting assay. It has been established that these ligands are selective for G4 over duplexes and show a preference for the parallel conformation. Next, telomerase inhibition ability has been assessed using three cell lines (K562, MyLa and MV-4-11) and telomerase activity is no longer detected at 0.1 μM concentration for the most potent ligand 1c. The most promising G4 ligands were also tested for antiproliferative activity against the two human myeloid leukaemia cell lines, HL60 and K562.
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Affiliation(s)
- Rabindra Nath Das
- Université de Bordeaux, ARNA laboratory, INSERM U1212, UMR CNRS 5320, UFR des Sciences Pharmaceutiques, 33076 Bordeaux CEDEX, France.
| | - Edith Chevret
- Université de Bordeaux, INSERM U1053, Cutaneous Lymphoma Oncogenesis Team, 33076 Bordeaux CEDEX, France.
| | - Vanessa Desplat
- Université de Bordeaux, INSERM U1035, Cellules souches hématopoïétiques normales et leucémiques, UFR des Sciences Pharmaceutiques, 33076 Bordeaux CEDEX, France.
| | - Sandra Rubio
- Université de Bordeaux, ARNA laboratory, INSERM U1212, UMR CNRS 5320, UFR des Sciences Pharmaceutiques, 33076 Bordeaux CEDEX, France.
| | - Jean-Louis Mergny
- Université de Bordeaux, ARNA laboratory, INSERM U1212, UMR CNRS 5320, UFR des Sciences Pharmaceutiques, 33076 Bordeaux CEDEX, France.
- Institute of Biophysics of the CAS, v.v.i., Královopolská 135, 612 65 Brno, Czech Republic.
| | - Jean Guillon
- Université de Bordeaux, ARNA laboratory, INSERM U1212, UMR CNRS 5320, UFR des Sciences Pharmaceutiques, 33076 Bordeaux CEDEX, France.
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29
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A G-quadruplex structure at the 5' end of the H19 coding region regulates H19 transcription. Sci Rep 2017; 8:45815. [PMID: 28367967 PMCID: PMC5377947 DOI: 10.1038/srep45815] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 03/06/2017] [Indexed: 12/15/2022] Open
Abstract
The H19 gene, one of the best known imprinted genes, encodes a long non-coding RNA that regulates cell proliferation and differentiation. H19 RNA is widely expressed in embryonic tissues, but its expression is restricted in only a few tissues after birth. However, regulation of H19 gene expression remains poorly understood outside the context of genomic imprinting. Here we identified evolutionarily conserved guanine (G)-rich repeated motifs at the 5′ end of the H19 coding region that are consistent with theoretically deduced G-quadruplex sequences. Circular dichroism spectroscopy and electrophoretic mobility shift assays with G-quadruplex-specific ligands revealed that the G-rich motif, located immediately downstream of the transcription start site (TSS), forms a G-quadruplex structure in vitro. By using a series of mutant forms of H19 harboring deletion or G-to-A substitutions, we found that the H19-G-quadruplex regulates H19 gene expression. We further showed that transcription factors Sp1 and E2F1 were associated with the H19-G-quadruplex to either suppress or promote the H19 transcription, respectively. Moreover, H19 expression during differentiation of mouse embryonic stem cells appears to be regulated by a genomic H19 G-quadruplex. These results demonstrate that the G-quadruplex structure immediately downstream of the TSS functions as a novel regulatory element for H19 gene expression.
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30
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Sette M, D'Addabbo P, Kelly G, Cicconi A, Micheli E, Cacchione S, Poma A, Gargioli C, Giambra V, Frezza D. Evidence for a quadruplex structure in the polymorphic hs1.2 enhancer of the immunoglobulin heavy chain 3' regulatory regions and its conservation in mammals. Biopolymers 2017; 105:768-78. [PMID: 27287611 PMCID: PMC5516150 DOI: 10.1002/bip.22891] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 06/01/2016] [Indexed: 11/09/2022]
Abstract
Regulatory regions in the genome can act through a variety of mechanisms that range from the occurrence of histone modifications to the presence of protein-binding loci for self-annealing sequences. The final result is often the induction of a conformational change of the DNA double helix, which alters the accessibility of a region to transcription factors and consequently gene expression. A ∼300 kb regulatory region on chromosome 14 at the 3' end (3'RR) of immunoglobulin (Ig) heavy-chain genes shows very peculiar features, conserved in mammals, including enhancers and transcription factor binding sites. In primates, the 3'RR is present in two copies, both having a central enhancer named hs1.2. We previously demonstrated the association between different hs1.2 alleles and Ig plasma levels in immunopathology. Here, we present the analysis of a putative G-quadruplex structure (tetraplex) consensus site embedded in a variable number tandem repeat (one to four copies) of hs1.2 that is a distinctive element among the enhancer alleles, and an investigation of its three-dimensional structure using bioinformatics and spectroscopic approaches. We suggest that both the role of the enhancer and the alternative effect of the hs1.2 alleles may be achieved through their peculiar three-dimensional-conformational rearrangement. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 768-778, 2016.
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Affiliation(s)
- Marco Sette
- Department of Chemical Sciences and Technology, University of Roma "Tor Vergata,", Roma, Italy
| | - Pietro D'Addabbo
- Department of Biology, University of Bari "Aldo Moro", Bari, Italy
| | - Geoffrey Kelly
- MRC Biomedical NMR Centre, The Francis Crick Institute, Mill Hill Laboratory, London, UK
| | - Alessandro Cicconi
- Department of Biology and Biotechnology, Sapienza University, Roma, Italy.,Institute Pasteur-Fondazione Cenci-Bolognetti, Roma, Italy
| | - Emanuela Micheli
- Department of Biology and Biotechnology, Sapienza University, Roma, Italy.,Institute Pasteur-Fondazione Cenci-Bolognetti, Roma, Italy
| | - Stefano Cacchione
- Department of Biology and Biotechnology, Sapienza University, Roma, Italy.,Institute Pasteur-Fondazione Cenci-Bolognetti, Roma, Italy
| | - Anna Poma
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Cesare Gargioli
- Department of Biology, University of Roma "Tor Vergata,", Roma, Italy
| | | | - Domenico Frezza
- Department of Biology, University of Roma "Tor Vergata,", Roma, Italy
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31
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Chariker JH, Miller DM, Rouchka EC. Computational Analysis of G-Quadruplex Forming Sequences across Chromosomes Reveals High Density Patterns Near the Terminal Ends. PLoS One 2016; 11:e0165101. [PMID: 27776185 PMCID: PMC5077116 DOI: 10.1371/journal.pone.0165101] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 10/06/2016] [Indexed: 12/17/2022] Open
Abstract
G-quadruplex structures (G4) are found throughout the human genome and are known to play a regulatory role in a variety of molecular processes. Structurally, they have many configurations and can form from one or more DNA strands. At the gene level, they regulate gene expression and protein synthesis. In this paper, chromosomal-level patterns of distribution are analyzed on the human genome to identify high-level distribution patterns potentially related to global functional processes. Here we show unique high density banding patterns on individual chromosomes that are highly correlated, appearing in a mirror pattern, across forward and reverse DNA strands. The highest density of G4 sequences occurs within four megabases of one end of most chromosomes and contains G4 motifs that bind with zinc finger proteins. These findings suggest that G4 may play a role in global chromosomal processes such as those found in meiosis.
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Affiliation(s)
- Julia H. Chariker
- Department of Psychological and Brain Sciences, University of Louisville, Louisville, KY, United States of America
- Kentucky Biomedical Research Infrastructure Network Bioinformatics Core, University of Louisville, Louisville, KY, United States of America
| | - Donald M. Miller
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY, United States of America
- Department of Medicine, University of Louisville, Louisville, KY, United States of America
| | - Eric C. Rouchka
- Kentucky Biomedical Research Infrastructure Network Bioinformatics Core, University of Louisville, Louisville, KY, United States of America
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville KY, United States of America
- * E-mail:
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32
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Armas P, David A, Calcaterra NB. Transcriptional control by G-quadruplexes: In vivo roles and perspectives for specific intervention. Transcription 2016; 8:21-25. [PMID: 27696937 DOI: 10.1080/21541264.2016.1243505] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
G-quadruplexes are non-canonical DNA secondary structures involved in several genomic and molecular processes. Here, we summarize the main G-quadruplex features and evidences proving the in vivo role on the transcriptional regulation of genes required for zebrafish embryonic development. We also discuss alternative strategies for specifically interfering G-quadruplex in vivo.
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Affiliation(s)
- Pablo Armas
- a Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda , Rosario , Argentina
| | - Aldana David
- a Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda , Rosario , Argentina
| | - Nora B Calcaterra
- a Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda , Rosario , Argentina
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33
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Cogoi S, Xodo LE. G4 DNA in ras genes and its potential in cancer therapy. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1859:663-74. [PMID: 26855080 DOI: 10.1016/j.bbagrm.2016.02.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/24/2016] [Accepted: 02/02/2016] [Indexed: 02/07/2023]
Abstract
It is now well established that in the human genome the canonical double helix coexists with folded G-quadruplex structures that are known to have important biological functions. In this review we summarize the current knowledge on quadruplex formation in the promoters of the ras genes that are mutated in about 30% of all human cancers. We describe the nuclear proteins that recognize these unusual DNA structures and discuss their function in transcription. We also examine the formation of G-quadruplexes in the 5'-untranslated region of the ras transcripts and conclude this review by reporting strategies that use either ras G-quadruplexes or proteins recognizing the ras G-quadruplexes as targets of anticancer small molecules.
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Affiliation(s)
- Susanna Cogoi
- Department of Medical and Biological Sciences, University of Udine, P.le Kolbe 4, 33100 Udine, Italy.
| | - Luigi E Xodo
- Department of Medical and Biological Sciences, University of Udine, P.le Kolbe 4, 33100 Udine, Italy.
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Blocking the binding of WT1 to bcl-2 promoter by G-quadruplex ligand SYUIQ-FM05. Biochem Biophys Rep 2016; 5:346-352. [PMID: 28955841 PMCID: PMC5600358 DOI: 10.1016/j.bbrep.2015.12.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 12/21/2015] [Accepted: 12/29/2015] [Indexed: 11/23/2022] Open
Abstract
At present, wt1, a Wilms’ tumor suppressor gene, is recognized as a critical regulator of tumorigenesis and a potential therapeutic target. WT1 shows the ability to regulate the transcription of bcl-2 by binding to a GC-rich region in the promoter, which can then fold into a special DNA secondary structure called the G-quadruplex. This function merits the exploration of the effect of a G-quadruplex ligand on the binding and subsequent regulation of WT1 on the bcl-2 promoter. In the present study, WT1 was found to bind to the double strand containing the G-quadruplex-forming sequence of the bcl-2 promoter. However, the G-quadruplex ligand SYUIQ-FM05 effectively blocked this binding by interacting with the GC-rich sequence. Our new findings are significant in the exploration of new strategies to block WT1's transcriptional regulation for cancer-cell treatment. WT1 bound to double-stranded but not G-quadruplex structure in bcl-2′s promoter. G-quadruplexes ligand SYUIQ-FM05 blocked the binding of WT1 to bcl-2. SYUIQ-FM05's regulation effects depends on its interaction with GC-rich sequence.
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Gao J, Zybailov BL, Byrd AK, Griffin WC, Chib S, Mackintosh SG, Tackett AJ, Raney KD. Yeast transcription co-activator Sub1 and its human homolog PC4 preferentially bind to G-quadruplex DNA. Chem Commun (Camb) 2015; 51:7242-4. [PMID: 25813861 DOI: 10.1039/c5cc00742a] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Using a G-quadruplex bait, we identified the transcription co-activator Sub1 as a G-quadruplex binding protein by quantitative LC-MS/MS and demonstrated in vivo G-quadruplex binding by ChIP. In vitro, Sub1, and its human homolog PC4, bind preferentially to G-quadruplexes. This provides a possible mechanism by which G-quadruplexes can influence gene transcription.
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Affiliation(s)
- Jun Gao
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, 4301 West Markham Street, Slot 516, Little Rock, AR 72205, USA.
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Joo HN, Seo YJ. Using gold aggregation to probe the inhibition and destruction of the G-quadruplex structure by TT-dimerization. Bioorg Med Chem Lett 2015; 25:2434-7. [PMID: 25908518 DOI: 10.1016/j.bmcl.2015.03.061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 03/11/2015] [Accepted: 03/24/2015] [Indexed: 11/29/2022]
Abstract
Thrombin binding G-quadruplex oligonucleotide containing two TT-dimer fragments and a gold attachment (ODN G1-G) was designed and synthesized with the aim of understanding the TT-dimer effect in G-quadruplex formation. Our results showed that TT-dimer mutation induced by UV light inhibits the formation of and even destroys the G-quadruplex structure, as confirmed by UV, CD and melting temperature measurements. The structural change resulting from TT-dimer formation with DNA was additionally probed and was found to be accompanied by significant gold aggregation that was observed in the form of a signal change from red to blue.
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Affiliation(s)
- Han Na Joo
- Department of Chemistry, Chonbuk National University, Jeonju 561-756, South Korea
| | - Young Jun Seo
- Department of Chemistry, Chonbuk National University, Jeonju 561-756, South Korea; Department of Bioactive Material Sciences, Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756, South Korea.
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Beishline K, Azizkhan-Clifford J. Sp1 and the 'hallmarks of cancer'. FEBS J 2015; 282:224-58. [PMID: 25393971 DOI: 10.1111/febs.13148] [Citation(s) in RCA: 365] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 09/26/2014] [Accepted: 11/10/2014] [Indexed: 12/19/2022]
Abstract
For many years, transcription factor Sp1 was viewed as a basal transcription factor and relegated to a role in the regulation of so-called housekeeping genes. Identification of Sp1's role in recruiting the general transcription machinery in the absence of a TATA box increased its importance in gene regulation, particularly in light of recent estimates that the majority of mammalian genes lack a TATA box. In this review, we briefly consider the history of Sp1, the founding member of the Sp family of transcription factors. We review the evidence suggesting that Sp1 is highly regulated by post-translational modifications that positively and negatively affect the activity of Sp1 on a wide array of genes. Sp1 is over-expressed in many cancers and is associated with poor prognosis. Targeting Sp1 in cancer treatment has been suggested; however, our review of the literature on the role of Sp1 in the regulation of genes that contribute to the 'hallmarks of cancer' illustrates the extreme complexity of Sp1 functions. Sp1 both activates and suppresses the expression of a number of essential oncogenes and tumor suppressors, as well as genes involved in essential cellular functions, including proliferation, differentiation, the DNA damage response, apoptosis, senescence and angiogenesis. Sp1 is also implicated in inflammation and genomic instability, as well as epigenetic silencing. Given the apparently opposing effects of Sp1, a more complete understanding of the function of Sp1 in cancer is required to validate its potential as a therapeutic target.
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Affiliation(s)
- Kate Beishline
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
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Spink BC, Bloom MS, Wu S, Sell S, Schneider E, Ding X, Spink DC. Analysis of the AHR gene proximal promoter GGGGC-repeat polymorphism in lung, breast, and colon cancer. Toxicol Appl Pharmacol 2014; 282:30-41. [PMID: 25447411 DOI: 10.1016/j.taap.2014.10.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 09/26/2014] [Accepted: 10/27/2014] [Indexed: 02/05/2023]
Abstract
The aryl hydrocarbon receptor (AhR) regulates expression of numerous genes, including those of the CYP1 gene family. With the goal of determining factors that control AHR gene expression, our studies are focused on the role of the short tandem repeat polymorphism, (GGGGC)n, located in the proximal promoter of the human AHR gene. When luciferase constructs containing varying GGGGC repeats were transfected into cancer cell lines derived from the lung, colon, and breast, the number of GGGGC repeats affected AHR promoter activity. The number of GGGGC repeats was determined in DNA from 327 humans and from 38 samples representing 5 species of non-human primates. In chimpanzees and 3 species of macaques, only (GGGGC)2 alleles were observed; however, in western gorilla, (GGGGC)n alleles with n=2, 4, 5, 6, 7, and 8 were identified. In all human populations examined, the frequency of (GGGGC)n was n=4>5≫2, 6. When frequencies of the (GGGGC)n alleles in DNA from patients with lung, colon, or breast cancer were evaluated, the occurrence of (GGGGC)2 was found to be 8-fold more frequent among lung cancer patients in comparison with its incidence in the general population, as represented by New York State neonates. Analysis of matched tumor and non-tumor DNA samples from the same individuals provided no evidence of microsatellite instability. These studies indicate that the (GGGGC)n short tandem repeats are inherited, and that the (GGGGC)2 allele in the AHR proximal promoter region should be further investigated with regard to its potential association with lung cancer susceptibility.
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Affiliation(s)
- Barbara C Spink
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, United States
| | - Michael S Bloom
- Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12201, United States
| | - Susan Wu
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, United States
| | - Stewart Sell
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, United States; Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12201, United States
| | - Erasmus Schneider
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, United States; Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12201, United States
| | - Xinxin Ding
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, United States; Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12201, United States; Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12201, United States
| | - David C Spink
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, United States; Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12201, United States.
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NADAI MATTEO, CIMINO-REALE GRAZIELLA, SATTIN GIOVANNA, DORIA FILIPPO, BUTOVSKAYA ELENA, ZAFFARONI NADIA, FRECCERO MAURO, PALUMBO MANLIO, RICHTER SARAN, FOLINI MARCO. Assessment of gene promoter G-quadruplex binding and modulation by a naphthalene diimide derivative in tumor cells. Int J Oncol 2014; 46:369-80. [DOI: 10.3892/ijo.2014.2723] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/03/2014] [Indexed: 11/05/2022] Open
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Abe H, Gemmell NJ. Abundance, arrangement, and function of sequence motifs in the chicken promoters. BMC Genomics 2014; 15:900. [PMID: 25318583 PMCID: PMC4203960 DOI: 10.1186/1471-2164-15-900] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 10/08/2014] [Indexed: 01/01/2023] Open
Abstract
Background Eukaryotic promoters are regions containing various sequence motifs necessary to control gene transcription. Much evidence has emerged showing that structural and/or contextual changes in regulatory elements can critically affect cis-regulatory activity. As sequence motifs can be key factors in maintaining complex promoter architectures, one effective approach to further understand the evolution of promoter regions in vertebrates is to compare the abundance and distribution patterns of sequence motifs in these regions between divergent species. When compared with mammals, the chicken (Gallus gallus) has a very different genome composition and sufficient genomic information to make it a good model for the exploration of promoter structure and evolution. Results More than 10% of chicken genes contained short tandem repeat (STR) in the region 2 kb upstream of promoters, but the total number of STRs observed in chicken is approximately half of that detected in human promoters. In terms of the STR motif frequencies, chicken promoter regions were more similar to other avian and mammalian promoters than these were to the entire chicken genome. Unlike other STRs, nearly half of the trinucleotide repeats found in promoters partly or entirely overlapped with CpG islands, indicating potential association with nucleosome positions. Moreover, the chicken promoters are abundant with sequence motifs such as poly-A, poly-G and G-quadruplexes, especially in the core region, that are otherwise rare in the genome. Most of sequence motifs showed strong functional enrichment for particular gene ontology (GO) categories, indicating roles in regulation of transcription and gene expression, as well as immune response and cognition. Conclusions Chicken promoter regions share some, but not all, of the structural features observed in mammalian promoters. The findings presented here provide empirical evidence suggesting that the frequencies and locations of STR motifs have been conserved through promoter evolution in a lineage-specific manner. Correlation analysis between GO categories and sequence motifs suggests motif-specific constraints acting on gene function. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-900) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hideaki Abe
- Department of Anatomy, University of Otago, Dunedin, New Zealand.
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Sun H, Xiang J, Shi Y, Yang Q, Guan A, Li Q, Yu L, Shang Q, Zhang H, Tang Y, Xu G. A newly identified G-quadruplex as a potential target regulating Bcl-2 expression. Biochim Biophys Acta Gen Subj 2014; 1840:3052-7. [PMID: 25086254 DOI: 10.1016/j.bbagen.2014.07.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 07/10/2014] [Accepted: 07/21/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND A new G-quadruplex structure located in the B-cell CLL/lymphoma 2 (Bcl-2) P1 promoter and its physiological function related to Bcl-2 transcription have been studied to find a potential anticancer therapeutic target. METHODS Absorption, polyacrylamide gel electrophoresis, fluorescence, circular dichroism, and nuclear magnetic resonance spectra have been employed to determine G-quadruplex structure and the interaction between G-quadruplex and phenanthrolin-dicarboxylate. Real time polymerase chain reaction and luciferase assay were done to assess the physiological function of the G-quadruplex structure. RESULTS The UV-melting and polyacrylamide gel electrophoresis studies show that the p32 DNA sequence forms an intramolecular G-quadruplex structure. Circular dichroism and nuclear magnetic resonance spectra indicate that the G-quadruplex is a hybrid-type structure with four G-tetrads. Fluorescence spectra show that a phenanthroline derivative has a higher binding affinity for p32 G-quadruplex than duplex. Further circular dichroism and nuclear magnetic resonance studies indicate that the phenanthroline derivative can regulate p32 G-quadruplex conformation. Real time polymerase chain reaction and luciferase assays show that the phenanthroline derivative has down-modulated Bcl-2 transcription activity in a concentration-dependent manner. However, no such effect was observed when p32 G-quadruplex was denatured through base mutation. CONCLUSION The newly identified G-quadruplex located in the P1 promoter of Bcl-2 oncogene is intimately related with Bcl-2 transcription activity, which may be a promising anticancer therapeutic target. GENERAL SIGNIFICANCE The newly identified G-quadruplex in the Bcl-2 P1 promoter may be a novel anticancer therapeutic target.
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Affiliation(s)
- Hongxia Sun
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.
| | - Junfeng Xiang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Yunhua Shi
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Yuquan Road 19(A), Shijingshan District, Beijing 100049, PR China
| | - Qianfan Yang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Aijiao Guan
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Qian Li
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Lijia Yu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Yuquan Road 19(A), Shijingshan District, Beijing 100049, PR China
| | - Qian Shang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Hong Zhang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Yalin Tang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.
| | - Guangzhi Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China
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Cogoi S, Shchekotikhin AE, Xodo LE. HRAS is silenced by two neighboring G-quadruplexes and activated by MAZ, a zinc-finger transcription factor with DNA unfolding property. Nucleic Acids Res 2014; 42:8379-88. [PMID: 25013182 PMCID: PMC4117790 DOI: 10.1093/nar/gku574] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The HRAS promoter contains immediately upstream of the transcription start site two neighboring G-elements, each capable of folding into a G-quadruplex structure. We have previously found that these G-quadruplexes bind to the zinc-finger transcription factors MAZ and Sp1. In the present study we have examined the interaction between the HRAS promoter and MAZ, demonstrating for the first time that the protein unfolds the G-quadruplex structures. We also demonstrate that MAZ-GST, in the presence of the complementary strands, promotes a rapid transformation of the two HRAS quadruplexes into duplexes. By a mutational analysis of the HRAS G-elements, we dissected the MAZ-binding sites from the quadruplex-forming motifs, finding that the two neighboring G-quadruplexes bring about a dramatic repression of transcription, in a synergistic manner. We also discovered that the two G-quadruplexes are strong targets for small anticancer molecules. We found that a cell-penetrating anthratiophenedione (ATPD-1), which binds tightly to the G-quadruplexes (ΔT > 15°C), promotes the total extinction of HRAS transcription. In contrast, when one of the two G-quadruplexes was abrogated by point mutations, ATPD-1 repressed transcription by only 50%. Our study provides relevant information for the rationale design of targeted therapy drugs specific for the HRAS oncogene.
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Affiliation(s)
- Susanna Cogoi
- Department of Medical and Biological Sciences, School of Medicine, P.le Kolbe 4, 33100 Udine, Italy
| | - Andrey E Shchekotikhin
- Gause Institute of New Antibiotics, Russian Academy of Medical Sciences, B. Pirogovskaya, 11, Moscow 119021, Russia Mendeleyev University of Chemical Technology, 9 Miusskaya Square, Moscow 125190, Russia
| | - Luigi E Xodo
- Department of Medical and Biological Sciences, School of Medicine, P.le Kolbe 4, 33100 Udine, Italy
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Guerrero-Bosagna C, Weeks S, Skinner MK. Identification of genomic features in environmentally induced epigenetic transgenerational inherited sperm epimutations. PLoS One 2014; 9:e100194. [PMID: 24937757 PMCID: PMC4061094 DOI: 10.1371/journal.pone.0100194] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 05/22/2014] [Indexed: 11/19/2022] Open
Abstract
A variety of environmental toxicants have been shown to induce the epigenetic transgenerational inheritance of disease and phenotypic variation. The process involves exposure of a gestating female and the developing fetus to environmental factors that promote permanent alterations in the epigenetic programming of the germline. The molecular aspects of the phenomenon involve epigenetic modifications (epimutations) in the germline (e.g. sperm) that are transmitted to subsequent generations. The current study integrates previously described experimental epigenomic transgenerational data and web-based bioinformatic analyses to identify genomic features associated with these transgenerationally transmitted epimutations. A previously identified genomic feature associated with these epimutations is a low CpG density (<12/100bp). The current observations suggest the transgenerational differential DNA methylation regions (DMR) in sperm contain unique consensus DNA sequence motifs, zinc finger motifs and G-quadruplex sequences. Interaction of molecular factors with these sequences could alter chromatin structure and accessibility of proteins with DNA methyltransferases to alter de novo DNA methylation patterns. G-quadruplex regions can promote the opening of the chromatin that may influence the action of DNA methyltransferases, or factors interacting with them, for the establishment of epigenetic marks. Zinc finger binding factors can also promote this chromatin remodeling and influence the expression of non-coding RNA. The current study identified genomic features associated with sperm epimutations that may explain in part how these sites become susceptible for transgenerational programming.
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Affiliation(s)
- Carlos Guerrero-Bosagna
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, Washington, United States of America
- Department of Physics, Biology and Chemistry, Linköping University, Linköping, Sweden
| | - Shelby Weeks
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, Washington, United States of America
| | - Michael K. Skinner
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, Washington, United States of America
- * E-mail:
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Frees S, Menendez C, Crum M, Bagga PS. QGRS-Conserve: a computational method for discovering evolutionarily conserved G-quadruplex motifs. Hum Genomics 2014; 8:8. [PMID: 24885782 PMCID: PMC4017754 DOI: 10.1186/1479-7364-8-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 04/21/2014] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Nucleic acids containing guanine tracts can form quadruplex structures via non-Watson-Crick base pairing. Formation of G-quadruplexes is associated with the regulation of important biological functions such as transcription, genetic instability, DNA repair, DNA replication, epigenetic mechanisms, regulation of translation, and alternative splicing. G-quadruplexes play important roles in human diseases and are being considered as targets for a variety of therapies. Identification of functional G-quadruplexes and the study of their overall distribution in genomes and transcriptomes is an important pursuit. Traditional computational methods map sequence motifs capable of forming G-quadruplexes but have difficulty in distinguishing motifs that occur by chance from ones which fold into G-quadruplexes. RESULTS We present Quadruplex forming 'G'-rich sequences (QGRS)-Conserve, a computational method for calculating motif conservation across exomes and supports filtering to provide researchers with more precise methods of studying G-quadruplex distribution patterns. Our method quantitatively evaluates conservation between quadruplexes found in homologous nucleotide sequences based on several motif structural characteristics. QGRS-Conserve also efficiently manages overlapping G-quadruplex sequences such that the resulting datasets can be analyzed effectively. CONCLUSIONS We have applied QGRS-Conserve to identify a large number of G-quadruplex motifs in the human exome conserved across several mammalian and non-mammalian species. We have successfully identified multiple homologs of many previously published G-quadruplexes that play post-transcriptional regulatory roles in human genes. Preliminary large-scale analysis identified many homologous G-quadruplexes in the 5'- and 3'-untranslated regions of mammalian species. An expectedly smaller set of G-quadruplex motifs was found to be conserved across larger phylogenetic distances. QGRS-Conserve provides means to build datasets that can be filtered and categorized in a variety of biological dimensions for more targeted studies in order to better understand the roles that G-quadruplexes play.
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Affiliation(s)
- Scott Frees
- Department of Computer Science, Ramapo College of New Jersey, 505 Ramapo Valley Road, Mahwah, NJ 08807, USA
| | - Camille Menendez
- Department of Bioinformatics, Ramapo College of New Jersey, 505 Ramapo Valley Road, Mahwah, NJ 08807, USA
| | - Matt Crum
- Department of Bioinformatics, Ramapo College of New Jersey, 505 Ramapo Valley Road, Mahwah, NJ 08807, USA
| | - Paramjeet S Bagga
- Department of Bioinformatics, Ramapo College of New Jersey, 505 Ramapo Valley Road, Mahwah, NJ 08807, USA
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Amrane S, Kerkour A, Bedrat A, Vialet B, Andreola ML, Mergny JL. Topology of a DNA G-quadruplex structure formed in the HIV-1 promoter: a potential target for anti-HIV drug development. J Am Chem Soc 2014; 136:5249-52. [PMID: 24649937 DOI: 10.1021/ja501500c] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Nucleic acid sequences containing guanine tracts are able to adopt noncanonical four-stranded nucleic acid structures called G-quadruplexes (G4s). These structures are based on the stacking of two or more G-tetrads; each tetrad is a planar association of four guanines held together by eight hydrogen bonds. In this study, we analyzed a conserved G-rich region from HIV-1 promoter that is known to regulate the transcription of the HIV-1 provirus. Strikingly, our analysis of an alignment of 1684 HIV-1 sequences from this region showed a high conservation of the ability to form G4 structures despite a lower conservation of the nucleotide primary sequence. Using NMR spectroscopy, we determined the G4 topology adopted by a DNA sequence from this region (HIV-PRO1: 5' TGGCCTGGGCGGGACTGGG 3'). This DNA fragment formed a stable two G-tetrad antiparallel G4 with an additional Watson-Crick CG base pair. This hybrid structure may be critical for HIV-1 gene expression and is potentially a novel target for anti-HIV-1 drug development.
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Kim IS, Seo YJ. Probe development for detection of TERRA 1 intramolecular G-quadruplex formation using a fluorescent adenosine derivative. Bioorg Med Chem Lett 2014; 24:1589-91. [PMID: 24513043 DOI: 10.1016/j.bmcl.2014.01.068] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 01/09/2014] [Accepted: 01/22/2014] [Indexed: 01/20/2023]
Abstract
We developed a probing system to detect the intramolecular G-quadruplex of telomeric repeat-containing RNA (TERRA 1). We used a fluorescent adenosine derivative rA(py) as a fluorophore and incorporated it into the dangling position of the parallel-type G-quadruplex sequence of TERRA 1. The rA(py)-modified G-quadruplex structure exhibited a strong fluorescence emission signal, while the emission signals of the single-strand and duplex structures were much lower.
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Affiliation(s)
- In Sun Kim
- Department of Chemistry, Chonbuk National University, Jeonju 561-756, South Korea
| | - Young Jun Seo
- Department of Chemistry, Chonbuk National University, Jeonju 561-756, South Korea.
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Bagga JS, D’Antonio LA. Role of conserved cis-regulatory elements in the post-transcriptional regulation of the human MECP2 gene involved in autism. Hum Genomics 2013; 7:19. [PMID: 24040966 PMCID: PMC3844687 DOI: 10.1186/1479-7364-7-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 09/04/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The MECP2 gene codes for methyl CpG binding protein 2 which regulates activities of other genes in the early development of the brain. Mutations in this gene have been associated with Rett syndrome, a form of autism. The purpose of this study was to investigate the role of evolutionarily conserved cis-elements in regulating the post-transcriptional expression of the MECP2 gene and to explore their possible correlations with a mutation that is known to cause mental retardation. RESULTS A bioinformatics approach was used to map evolutionarily conserved cis-regulatory elements in the transcribed regions of the human MECP2 gene and its mammalian orthologs. Cis-regulatory motifs including G-quadruplexes, microRNA target sites, and AU-rich elements have gained significant importance because of their role in key biological processes and as therapeutic targets. We discovered in the 5'-UTR (untranslated region) of MECP2 mRNA a highly conserved G-quadruplex which overlapped a known deletion in Rett syndrome patients with decreased levels of MeCP2 protein. We believe that this 5'-UTR G-quadruplex could be involved in regulating MECP2 translation. We mapped additional evolutionarily conserved G-quadruplexes, microRNA target sites, and AU-rich elements in the key sections of both untranslated regions. Our studies suggest the regulation of translation, mRNA turnover, and development-related alternative MECP2 polyadenylation, putatively involving interactions of conserved cis-regulatory elements with their respective trans factors and complex interactions among the trans factors themselves. We discovered highly conserved G-quadruplex motifs that were more prevalent near alternative splice sites as compared to the constitutive sites of the MECP2 gene. We also identified a pair of overlapping G-quadruplexes at an alternative 5' splice site that could potentially regulate alternative splicing in a negative as well as a positive way in the MECP2 pre-mRNAs. CONCLUSIONS A Rett syndrome mutation with decreased protein expression was found to be associated with a conserved G-quadruplex. Our studies suggest that MECP2 post-transcriptional gene expression could be regulated by several evolutionarily conserved cis-elements like G-quadruplex motifs, microRNA target sites, and AU-rich elements. This phylogenetic analysis has provided some interesting and valuable insights into the regulation of the MECP2 gene involved in autism.
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Affiliation(s)
- Joetsaroop S Bagga
- John P. Stevens High School, 855 Grove Ave., Edison, NJ 08820, USA
- Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213, USA
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Cogoi S, Shchekotikhin AE, Membrino A, Sinkevich YB, Xodo LE. Guanidino Anthrathiophenediones as G-Quadruplex Binders: Uptake, Intracellular Localization, and Anti-Harvey-ras Gene Activity in Bladder Cancer Cells. J Med Chem 2013; 56:2764-78. [DOI: 10.1021/jm3019063] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Susanna Cogoi
- Department of Medical and Biological
Science, P.le Kolbe 4, School of Medicine, 33100 Udine, Italy
| | - Andrey E. Shchekotikhin
- Gause
Institute of New Antibiotics, Russian Academy of Medical Sciences, B. Pirogovskaya,
11, Moscow 119021, Russia
| | - Alexandro Membrino
- Department of Medical and Biological
Science, P.le Kolbe 4, School of Medicine, 33100 Udine, Italy
| | - Yuri B. Sinkevich
- Mendeleyev University of Chemical Technology, 9 Miusskaya Square, Moscow 125190,
Russia
| | - Luigi E. Xodo
- Department of Medical and Biological
Science, P.le Kolbe 4, School of Medicine, 33100 Udine, Italy
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49
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Zhou W, Suntharalingam K, Brand NJ, Barton PJR, Vilar R, Ying L. Possible regulatory roles of promoter g-quadruplexes in cardiac function-related genes - human TnIc as a model. PLoS One 2013; 8:e53137. [PMID: 23326389 PMCID: PMC3541360 DOI: 10.1371/journal.pone.0053137] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 11/23/2012] [Indexed: 12/15/2022] Open
Abstract
G-quadruplexes (G4s) are four-stranded DNA secondary structures, which are involved in a diverse range of biological processes. Although the anti-cancer potential of G4s in oncogene promoters has been thoroughly investigated, the functions of promoter G4s in non-cancer-related genes are not well understood. We have explored the possible regulatory roles of promoter G4s in cardiac function-related genes using both computational and a wide range of experimental approaches. According to our bioinformatics results, it was found that potential G4-forming sequences are particularly enriched in the transcription regulatory regions (TRRs) of cardiac function-related genes. Subsequently, the promoter of human cardiac troponin I (TnIc) was chosen as a model, and G4s found in this region were subjected to biophysical characterisations. The chromosome 19 specific minisatellite G4 sequence (MNSG4) and near transcription start site (TSS) G4 sequence (−80 G4) adopt anti-parallel and parallel structures respectively in 100 mM KCl, with stabilities comparable to those of oncogene G4s. It was also found that TnIc G4s act cooperatively as enhancers in gene expression regulation in HEK293 cells, when stabilised by a synthetic G4-binding ligand. This study provides the first evidence of the biological significance of promoter G4s in cardiac function-related genes. The feasibility of using a single ligand to target multiple G4s in a particular gene has also been discussed.
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Affiliation(s)
- Wenhua Zhou
- Molecular Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | | | - Nigel J. Brand
- Harefield Heart Science Centre, National Heart and Lung Institute, Imperial College London, Middlesex, United Kingdom
| | - Paul J. R. Barton
- Harefield Heart Science Centre, National Heart and Lung Institute, Imperial College London, Middlesex, United Kingdom
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Trust, London, United Kingdom
| | - Ramon Vilar
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Liming Ying
- Molecular Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
- * E-mail:
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50
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Baral A, Kumar P, Pathak R, Chowdhury S. Emerging trends in G-quadruplex biology – role in epigenetic and evolutionary events. MOLECULAR BIOSYSTEMS 2013; 9:1568-75. [DOI: 10.1039/c3mb25492e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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