1
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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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2
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Galati E, Bosio MC, Novarina D, Chiara M, Bernini GM, Mozzarelli AM, García-Rubio ML, Gómez-González B, Aguilera A, Carzaniga T, Todisco M, Bellini T, Nava GM, Frigè G, Sertic S, Horner DS, Baryshnikova A, Manzari C, D'Erchia AM, Pesole G, Brown GW, Muzi-Falconi M, Lazzaro F. VID22 counteracts G-quadruplex-induced genome instability. Nucleic Acids Res 2021; 49:12785-12804. [PMID: 34871443 PMCID: PMC8682794 DOI: 10.1093/nar/gkab1156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 10/19/2021] [Accepted: 11/08/2021] [Indexed: 12/17/2022] Open
Abstract
Genome instability is a condition characterized by the accumulation of genetic alterations and is a hallmark of cancer cells. To uncover new genes and cellular pathways affecting endogenous DNA damage and genome integrity, we exploited a Synthetic Genetic Array (SGA)-based screen in yeast. Among the positive genes, we identified VID22, reported to be involved in DNA double-strand break repair. vid22Δ cells exhibit increased levels of endogenous DNA damage, chronic DNA damage response activation and accumulate DNA aberrations in sequences displaying high probabilities of forming G-quadruplexes (G4-DNA). If not resolved, these DNA secondary structures can block the progression of both DNA and RNA polymerases and correlate with chromosome fragile sites. Vid22 binds to and protects DNA at G4-containing regions both in vitro and in vivo. Loss of VID22 causes an increase in gross chromosomal rearrangement (GCR) events dependent on G-quadruplex forming sequences. Moreover, the absence of Vid22 causes defects in the correct maintenance of G4-DNA rich elements, such as telomeres and mtDNA, and hypersensitivity to the G4-stabilizing ligand TMPyP4. We thus propose that Vid22 is directly involved in genome integrity maintenance as a novel regulator of G4 metabolism.
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Affiliation(s)
- Elena Galati
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Maria C Bosio
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Daniele Novarina
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Matteo Chiara
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy.,Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Giulia M Bernini
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Alessandro M Mozzarelli
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Maria L García-Rubio
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, Seville, Spain
| | - Belén Gómez-González
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, Seville, Spain
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, Seville, Spain
| | - Thomas Carzaniga
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, via Vanvitelli 32, 20129 Milan, Italy
| | - Marco Todisco
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, via Vanvitelli 32, 20129 Milan, Italy
| | - Tommaso Bellini
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, via Vanvitelli 32, 20129 Milan, Italy
| | - Giulia M Nava
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Gianmaria Frigè
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Via Adamello 16, 20139 Milan, Italy
| | - Sarah Sertic
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - David S Horner
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy.,Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Anastasia Baryshnikova
- Department of Molecular Genetics and Donnelly Centre, University of Toronto, Toronto, Canada
| | - Caterina Manzari
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Anna M D'Erchia
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari, Consiglio Nazionale delle Ricerche, Bari, Italy.,Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università di Bari 'A. Moro', Bari, Italy
| | - Graziano Pesole
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari, Consiglio Nazionale delle Ricerche, Bari, Italy.,Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università di Bari 'A. Moro', Bari, Italy
| | - Grant W Brown
- Department of Biochemistry and Donnelly Centre, University of Toronto, Ontario M5S 3E1, Toronto, Canada
| | - Marco Muzi-Falconi
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Federico Lazzaro
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
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3
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Sengupta P, Banerjee N, Roychowdhury T, Dutta A, Chattopadhyay S, Chatterjee S. Site-specific amino acid substitution in dodecameric peptides determines the stability and unfolding of c-MYC quadruplex promoting apoptosis in cancer cells. Nucleic Acids Res 2019; 46:9932-9950. [PMID: 30239898 PMCID: PMC6212778 DOI: 10.1093/nar/gky824] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 09/11/2018] [Indexed: 12/11/2022] Open
Abstract
c-MYC proto-oncogene harbours a transcription-inhibitory quadruplex-forming scaffold (Pu27) upstream P1 promoter providing anti-neoplastic therapeutic target. Previous reports showed the binding profile of human Cathelicidin peptide (LL37) and telomeric G-quadruplex. Here, we truncated the quadruplex-binding domain of LL37 to prepare a small library of peptides through site-specific amino acid substitution. We investigated the intracellular selectivity of peptides for Pu27 over other oncogenic quadruplexes and their role in c-MYC promoter repression by dual-luciferase assays. We analysed their thermodynamics of binding reactions with c-MYC quadruplex isomers (Pu27, Myc22, Pu19) by Isothermal Titration Calorimetry. We discussed how amino acid substitutions and peptide helicity enhanced/weakened their affinities for c-MYC quadruplexes and characterized specific non-covalent inter-residual interactions determining their selectivity. Solution NMR structure indicated that KR12C, the best peptide candidate, selectively stabilized the 5′-propeller loop of c-MYC quadruplex by arginine-driven electrostatic-interactions at the sugar-phosphate backbone while KR12A peptide destabilized the quadruplex inducing a single-stranded hairpin-like conformation. Chromatin immunoprecipitations envisaged that KR12C and KR12A depleted and enriched Sp1 and NM23-H2 (Nucleoside diphosphate kinase) occupancy at Pu27 respectively supporting their regulation in stabilizing and unfolding c-MYC quadruplex in MCF-7 cells. We deciphered that selective arresting of c-MYC transcription by KR12C triggered apoptotic-signalling pathway via VEGF-A-BCL-2 axis.
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Affiliation(s)
- Pallabi Sengupta
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Nilanjan Banerjee
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Tanaya Roychowdhury
- Cancer Biology and Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700032, India
| | - Anindya Dutta
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Samit Chattopadhyay
- Cancer Biology and Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700032, India
| | - Subhrangsu Chatterjee
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
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4
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Sengupta P, Bhattacharya A, Sa G, Das T, Chatterjee S. Truncated G-Quadruplex Isomers Cross-Talk with the Transcription Factors To Maintain Homeostatic Equilibria in c-MYC Transcription. Biochemistry 2019; 58:1975-1991. [PMID: 30920805 DOI: 10.1021/acs.biochem.9b00030] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The nuclease hypersensitive element III1 (NHE III1) upstream c-MYC promoter harbors a transcription-silencing G-quadruplex (Pu27) element. Dynamic turnover of various transcription factors (TFs) across Pu27 to control c-MYC transcription homeostasis is enigmatic. Here, we reveal that native Pu27 evolves truncated G-quadruplex isomers (Pu19, Pu22, Pu24, and Pu25) in cells that are optimal intracellular targets of specific TFs in a sequence- and structure-dependent manner. Nuclear magnetic resonance and isothermal titration calorimetry envisaged that NM23-H2 (nucleoside diphosphate kinase) and nucleolin induce conformational fluctuations in Pu27 to sample specific conformationally restricted conformer(s). Structural investigations revealed that the flanking guanines at 5'-Pu27 control solvent exposure at G-quartets upon NM23-H2 and nucleolin binding driving Pu27 unfolding and folding, respectively. Transient chromatin immunoprecipitations confirmed that NM23-H2 drives the conformation switch to Pu24 that outcompetes nucleolin recruitment. Similarly, nucleolin arrests Pu27 in the Pu22 conformer minimizing NM23-H2 binding at Pu27. hnRNPK (heterogeneous nuclear ribonucleoprotein K) positively regulates NM23-H2 and nucleolin association at Pu27 despite their antagonism. On the basis of these results, we simulated the transcription kinetics in a feed-forward loop in which the transcription output responds to hnRNPK-induced early activation via NM23-H2 association, which favors Pu24 formation at NHE III1 reducing nucleolin occupancy and driving quadruplex unfolding to initiate transcription. NM23-H2 further promotes hnRNPK deposition across NHE III1 altering Pu27 plasticity that finally enriches the nucleolin abundance to drive Pu22 formation and weaken NM23-H2 binding to extinguish transcription. This mechanism involves three positive feedback loops (NM23-H2-hnRNPK, NM23-H2-CNBP, and hnRNPK-nucleolin) and one negative feedback loop (NM23-H2-nucleolin) controlling optimal turnover and residence time of TFs at Pu27 to homeostatically regulate c-MYC transcription.
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Affiliation(s)
- Pallabi Sengupta
- Department of Biophysics , Bose Institute , P 1/12, C. I. T. Road, Scheme-VIIM , Kolkata 700054 , West Bengal , India
| | - Apoorva Bhattacharya
- Division of Molecular Medicine , Bose Institute , P 1/12, C. I. T. Road, Scheme-VIIM , Kolkata 700054 , West Bengal , India
| | - Gaurisankar Sa
- Division of Molecular Medicine , Bose Institute , P 1/12, C. I. T. Road, Scheme-VIIM , Kolkata 700054 , West Bengal , India
| | - Tanya Das
- Division of Molecular Medicine , Bose Institute , P 1/12, C. I. T. Road, Scheme-VIIM , Kolkata 700054 , West Bengal , India
| | - Subhrangsu Chatterjee
- Department of Biophysics , Bose Institute , P 1/12, C. I. T. Road, Scheme-VIIM , Kolkata 700054 , West Bengal , India
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5
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Holstein EM, Lawless C, Banks P, Lydall D. Genome-Wide Quantitative Fitness Analysis (QFA) of Yeast Cultures. Methods Mol Biol 2018; 1672:575-597. [PMID: 29043649 DOI: 10.1007/978-1-4939-7306-4_38] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We provide a detailed protocol for robot-assisted, genome-wide measurement of fitness in the model yeast Saccharomyces cerevisiae using Quantitative Fitness Analysis (QFA). We first describe how we construct thousands of double or triple mutant yeast strains in parallel using Synthetic Genetic Array (SGA) procedures. Strains are inoculated onto solid agar surfaces by liquid spotting followed by repeated photography of agar plates. Growth curves are constructed and the fitness of each strain is estimated. Robot-assisted QFA, can be used to identify genetic interactions and chemical sensitivity/resistance in genome-wide experiments, but QFA can also be used in smaller scale, manual workflows.
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Affiliation(s)
- Eva-Maria Holstein
- Institute for Cell & Molecular Biosciences, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Conor Lawless
- Institute for Cell & Molecular Biosciences, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Peter Banks
- Institute for Cell & Molecular Biosciences, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - David Lydall
- Institute for Cell & Molecular Biosciences, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
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6
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Lopez CR, Singh S, Hambarde S, Griffin WC, Gao J, Chib S, Yu Y, Ira G, Raney KD, Kim N. Yeast Sub1 and human PC4 are G-quadruplex binding proteins that suppress genome instability at co-transcriptionally formed G4 DNA. Nucleic Acids Res 2017; 45:5850-5862. [PMID: 28369605 PMCID: PMC5449603 DOI: 10.1093/nar/gkx201] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 03/15/2017] [Indexed: 01/05/2023] Open
Abstract
G-quadruplex or G4 DNA is a non-B secondary DNA structure consisting of a stacked array of guanine-quartets that can disrupt critical cellular functions such as replication and transcription. When sequences that can adopt Non-B structures including G4 DNA are located within actively transcribed genes, the reshaping of DNA topology necessary for transcription process stimulates secondary structure-formation thereby amplifying the potential for genome instability. Using a reporter assay designed to study G4-induced recombination in the context of an actively transcribed locus in Saccharomyces cerevisiae, we tested whether co-transcriptional activator Sub1, recently identified as a G4-binding factor, contributes to genome maintenance at G4-forming sequences. Our data indicate that, upon Sub1-disruption, genome instability linked to co-transcriptionally formed G4 DNA in Top1-deficient cells is significantly augmented and that its highly conserved DNA binding domain or the human homolog PC4 is sufficient to suppress G4-associated genome instability. We also show that Sub1 interacts specifically with co-transcriptionally formed G4 DNA in vivo and that yeast cells become highly sensitivity to G4-stabilizing chemical ligands by the loss of Sub1. Finally, we demonstrate the physical and genetic interaction of Sub1 with the G4-resolving helicase Pif1, suggesting a possible mechanism by which Sub1 suppresses instability at G4 DNA.
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Affiliation(s)
- Christopher R Lopez
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Shivani Singh
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Shashank Hambarde
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Wezley C Griffin
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Jun Gao
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Shubeena Chib
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Yang Yu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Grzegorz Ira
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kevin D Raney
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Nayun Kim
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.,The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
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7
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Rovozzo R, Korza G, Baker MW, Li M, Bhattacharyya A, Barbarese E, Carson JH. CGG Repeats in the 5'UTR of FMR1 RNA Regulate Translation of Other RNAs Localized in the Same RNA Granules. PLoS One 2016; 11:e0168204. [PMID: 28005950 PMCID: PMC5179066 DOI: 10.1371/journal.pone.0168204] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 11/28/2016] [Indexed: 01/24/2023] Open
Abstract
CGG repeats in the 5’UTR of Fragile X Mental Retardation 1 (FMR1) RNA mediate RNA localization and translation in granules. Large expansions of CGG repeats (> 200 repeats) in FMR1, referred to as full mutations, are associated with fragile X syndrome (FXS). Smaller expansions (55–200 repeats), referred to as premutations, are associated with fragile X tremor ataxia syndrome (FXTAS) and fragile X premature ovarian insufficiency (FXPOI). TMPyP4 is a porphyrin ring compound that destabilizes CGG repeat RNA secondary structure. Here we show that exogenous CGG repeat RNA by itself, lacking the FMRP ORF, microinjected into hippocampal neurons is localized in RNA granules and inhibits translation of ARC RNA, which is localized in the same granules. TMPyP4 rescues translation of ARC RNA in granules. We also show that in human premutation fibroblasts with endogenous CGG repeat expansions in the FMR1 gene, translation of ARC RNA is inhibited and calcium homeostasis is disrupted and both phenotypes are rescued by TMPyP4. Inhibition of granule translation by expanded CGG repeats and rescue of granule translation by TMPy4, represent potential pathogenic mechanism and therapeutic strategy, respectively, for FXTAS and FXPOI.
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Affiliation(s)
- René Rovozzo
- Center for Cell Analysis and Modeling, UConn Health, Farmington, Connecticut, United States of America
| | - George Korza
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, United States of America
| | - Mei W. Baker
- Departments of Pediatrics, School of Medicine and Public Health, University of Wisconsin-Madison, Wisconsin State Laboratory of Hygiene, Newborn Screening Laboratory, Madison, Wisconsin, United States of America
| | - Meng Li
- Waisman Center, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Anita Bhattacharyya
- Waisman Center, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Elisa Barbarese
- Department of Neuroscience, UConn Health, Farmington, Connecticut, United States of America
| | - John H. Carson
- Center for Cell Analysis and Modeling, UConn Health, Farmington, Connecticut, United States of America
- * E-mail:
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8
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Genetic Networks Required to Coordinate Chromosome Replication by DNA Polymerases α, δ, and ε in Saccharomyces cerevisiae. G3-GENES GENOMES GENETICS 2015; 5:2187-97. [PMID: 26297725 PMCID: PMC4593000 DOI: 10.1534/g3.115.021493] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Three major DNA polymerases replicate the linear eukaryotic chromosomes. DNA polymerase α-primase (Pol α) and DNA polymerase δ (Pol δ) replicate the lagging-strand and Pol α and DNA polymerase ε (Pol ε) the leading-strand. To identify factors affecting coordination of DNA replication, we have performed genome-wide quantitative fitness analyses of budding yeast cells containing defective polymerases. We combined temperature-sensitive mutations affecting the three replicative polymerases, Pol α, Pol δ, and Pol ε with genome-wide collections of null and reduced function mutations. We identify large numbers of genetic interactions that inform about the roles that specific genes play to help Pol α, Pol δ, and Pol ε function. Surprisingly, the overlap between the genetic networks affecting the three DNA polymerases does not represent the majority of the genetic interactions identified. Instead our data support a model for division of labor between the different DNA polymerases during DNA replication. For example, our genetic interaction data are consistent with biochemical data showing that Pol ε is more important to the Pre-Loading complex than either Pol α or Pol δ. We also observed distinct patterns of genetic interactions between leading- and lagging-strand DNA polymerases, with particular genes being important for coupling proliferating cell nuclear antigen loading/unloading (Ctf18, Elg1) with nucleosome assembly (chromatin assembly factor 1, histone regulatory HIR complex). Overall our data reveal specialized genetic networks that affect different aspects of leading- and lagging-strand DNA replication. To help others to engage with these data we have generated two novel, interactive visualization tools, DIXY and Profilyzer.
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9
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Zhang Y, Liu ZL, Song M. ChiNet uncovers rewired transcription subnetworks in tolerant yeast for advanced biofuels conversion. Nucleic Acids Res 2015; 43:4393-407. [PMID: 25897127 PMCID: PMC4482087 DOI: 10.1093/nar/gkv358] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 04/06/2015] [Indexed: 12/14/2022] Open
Abstract
Analysis of rewired upstream subnetworks impacting downstream differential gene expression aids the delineation of evolving molecular mechanisms. Cumulative statistics based on conventional differential correlation are limited for subnetwork rewiring analysis since rewiring is not necessarily equivalent to change in correlation coefficients. Here we present a computational method ChiNet to quantify subnetwork rewiring by statistical heterogeneity that enables detection of potential genotype changes causing altered transcription regulation in evolving organisms. Given a differentially expressed downstream gene set, ChiNet backtracks a rewired upstream subnetwork from a super-network including gene interactions known to occur under various molecular contexts. We benchmarked ChiNet for its high accuracy in distinguishing rewired artificial subnetworks, in silico yeast transcription-metabolic subnetworks, and rewired transcription subnetworks for Candida albicans versus Saccharomyces cerevisiae, against two differential-correlation based subnetwork rewiring approaches. Then, using transcriptome data from tolerant S. cerevisiae strain NRRL Y-50049 and a wild-type intolerant strain, ChiNet identified 44 metabolic pathways affected by rewired transcription subnetworks anchored to major adaptively activated transcription factor genes YAP1, RPN4, SFP1 and ROX1, in response to toxic chemical challenges involved in lignocellulose-to-biofuels conversion. These findings support the use of ChiNet in rewiring analysis of subnetworks where differential interaction patterns resulting from divergent nonlinear dynamics abound.
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Affiliation(s)
- Yang Zhang
- Department of Computer Science, New Mexico State University, Las Cruces, NM 88003, USA
| | - Z Lewis Liu
- National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, Peoria, IL 61604, USA
| | - Mingzhou Song
- Department of Computer Science, New Mexico State University, Las Cruces, NM 88003, USA
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10
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Chen BJ, Wu YL, Tanaka Y, Zhang W. Small molecules targeting c-Myc oncogene: promising anti-cancer therapeutics. Int J Biol Sci 2014; 10:1084-96. [PMID: 25332683 PMCID: PMC4202025 DOI: 10.7150/ijbs.10190] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 08/25/2014] [Indexed: 02/07/2023] Open
Abstract
The nuclear transcription factor c-Myc is a member of the Myc gene family with multiple functions and located on band q24.1 of chromosome 8. The c-Myc gene is activated by chromosomal translocation, rearrangement, and amplification. Its encoded protein transduces intracellular signals to the nucleus, resulting in the regulation of cell proliferation, differentiation, and apoptosis, and has the ability to transform cells and bind chromosomal DNA. c-Myc also plays a critical role in malignant transformation. The abnormal over-expression of c-Myc is frequently observed in some tumors, including carcinomas of the breast, colon, and cervix, as well as small-cell lung cancer, osteosarcomas, glioblastomas, and myeloid leukemias, therefore making it a possible target for anticancer therapy. In this minireview, we summarize unique characteristics of c-Myc and therapeutic strategies against cancer using small molecules targeting the oncogene, and discuss the prospects in the development of agents targeting c-Myc, in particular G-quadruplexes formed in c-Myc promoter and c-Myc/Max dimerization. Such information will be of importance for the research and development of c-Myc-targeted drugs.
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Affiliation(s)
- Bing-Jia Chen
- 1. Lab of Chemical Biology and Molecular Drug Design, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
| | - Yan-Ling Wu
- 2. Lab of Molecular Immunology, Virus Inspection Department, Zhejiang Provincial Center for Disease Control and Prevention, 630 Xincheng Road, Hangzhou, 310051, China. ; 1. Lab of Chemical Biology and Molecular Drug Design, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
| | - Yoshimasa Tanaka
- 3. Center for Innovation in Immunoregulative Technology and Therapeutics, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Wen Zhang
- 1. Lab of Chemical Biology and Molecular Drug Design, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
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11
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He Q, Zeng P, Tan JH, Ou TM, Gu LQ, Huang ZS, Li D. G-quadruplex-mediated regulation of telomere binding protein POT1 gene expression. Biochim Biophys Acta Gen Subj 2014; 1840:2222-33. [DOI: 10.1016/j.bbagen.2014.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Revised: 02/10/2014] [Accepted: 03/03/2014] [Indexed: 02/03/2023]
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Gaytán BD, Vulpe CD. Functional toxicology: tools to advance the future of toxicity testing. Front Genet 2014; 5:110. [PMID: 24847352 PMCID: PMC4017141 DOI: 10.3389/fgene.2014.00110] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 04/12/2014] [Indexed: 11/16/2022] Open
Abstract
The increased presence of chemical contaminants in the environment is an undeniable concern to human health and ecosystems. Historically, by relying heavily upon costly and laborious animal-based toxicity assays, the field of toxicology has often neglected examinations of the cellular and molecular mechanisms of toxicity for the majority of compounds—information that, if available, would strengthen risk assessment analyses. Functional toxicology, where cells or organisms with gene deletions or depleted proteins are used to assess genetic requirements for chemical tolerance, can advance the field of toxicity testing by contributing data regarding chemical mechanisms of toxicity. Functional toxicology can be accomplished using available genetic tools in yeasts, other fungi and bacteria, and eukaryotes of increased complexity, including zebrafish, fruit flies, rodents, and human cell lines. Underscored is the value of using less complex systems such as yeasts to direct further studies in more complex systems such as human cell lines. Functional techniques can yield (1) novel insights into chemical toxicity; (2) pathways and mechanisms deserving of further study; and (3) candidate human toxicant susceptibility or resistance genes.
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Affiliation(s)
- Brandon D Gaytán
- Department of Nutritional Science and Toxicology, University of California Berkeley Berkeley, CA, USA
| | - Chris D Vulpe
- Department of Nutritional Science and Toxicology, University of California Berkeley Berkeley, CA, USA
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Kwasiborski A, Bajji M, Renaut J, Delaplace P, Jijakli MH. Identification of metabolic pathways expressed by Pichia anomala Kh6 in the presence of the pathogen Botrytis cinerea on apple: new possible targets for biocontrol improvement. PLoS One 2014; 9:e91434. [PMID: 24614090 PMCID: PMC3948861 DOI: 10.1371/journal.pone.0091434] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 02/12/2014] [Indexed: 11/19/2022] Open
Abstract
Yeast Pichia anomala strain Kh6 Kurtzman (Saccharomycetales: Endomycetaceae) exhibits biological control properties that provide an alternative to the chemical fungicides currently used by fruit or vegetable producers against main post-harvest pathogens, such as Botrytis cinerea (Helotiales: Sclerotiniaceae). Using an in situ model that takes into account interactions between organisms and a proteomic approach, we aimed to identify P. anomala metabolic pathways influenced by the presence of B. cinerea. A total of 105 and 60 P. anomala proteins were differentially represented in the exponential and stationary growth phases, respectively. In the exponential phase and in the presence of B. cinerea, the pentose phosphate pathway seems to be enhanced and would provide P. anomala with the needed nucleic acids and energy for the wound colonisation. In the stationary phase, P. anomala would use alcoholic fermentation both in the absence and presence of the pathogen. These results would suggest that the competitive colonisation of apple wounds could be implicated in the mode of action of P. anomala against B. cinerea.
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Affiliation(s)
- Anthony Kwasiborski
- Plant Pathology Unit, Gembloux Agro-Bio Tech/University of Liège, Gembloux, Belgium
| | - Mohammed Bajji
- Plant Pathology Unit, Gembloux Agro-Bio Tech/University of Liège, Gembloux, Belgium
| | - Jenny Renaut
- Proteomics Platform, Department of Environment and Agrobiotechnologies/Centre de Recherche Public Gabriel Lippmann, Belvaux, Luxemburg
| | - Pierre Delaplace
- Plant Biology Unit, Gembloux Agro-Bio Tech/University of Liège, Gembloux, Belgium
| | - M. Haissam Jijakli
- Plant Pathology Unit, Gembloux Agro-Bio Tech/University of Liège, Gembloux, Belgium
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Lagah S, Tan IL, Radhakrishnan P, Hirst RA, Ward JH, O’Callaghan C, Smith SJ, Stevens MFG, Grundy RG, Rahman R. RHPS4 G-quadruplex ligand induces anti-proliferative effects in brain tumor cells. PLoS One 2014; 9:e86187. [PMID: 24454961 PMCID: PMC3893285 DOI: 10.1371/journal.pone.0086187] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 12/07/2013] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Telomeric 3' overhangs can fold into a four-stranded DNA structure termed G-quadruplex (G4), a formation which inhibits telomerase. As telomerase activation is crucial for telomere maintenance in most cancer cells, several classes of G4 ligands have been designed to directly disrupt telomeric structure. METHODS We exposed brain tumor cells to the G4 ligand 3,11-difluoro-6,8,13-trimethyl-8H-quino[4,3,2-kl]acridinium methosulfate (RHPS4) and investigated proliferation, cell cycle dynamics, telomere length, telomerase activity and activated c-Myc levels. RESULTS Although all cell lines tested were sensitive to RHPS4, PFSK-1 central nervous system primitive neuroectodermal cells, DAOY medulloblastoma cells and U87 glioblastoma cells exhibited up to 30-fold increased sensitivity compared to KNS42 glioblastoma, C6 glioma and Res196 ependymoma cells. An increased proportion of S-phase cells were observed in medulloblastoma and high grade glioma cells whilst CNS PNET cells showed an increased proportion of G1-phase cells. RHPS4-induced phenotypes were concomitant with telomerase inhibition, manifested in a telomere length-independent manner and not associated with activated c-Myc levels. However, anti-proliferative effects were also observed in normal neural/endothelial cells in vitro and ex vivo. CONCLUSION This study warrants in vivo validation of RHPS4 and alternative G4 ligands as potential anti-cancer agents for brain tumors but highlights the consideration of dose-limiting tissue toxicities.
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Affiliation(s)
- Sunil Lagah
- Children’s Brain Tumour Research Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - I-Li Tan
- Children’s Brain Tumour Research Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Priya Radhakrishnan
- Department of Infection, Immunity and Inflammation, Leicester Royal Infirmary, University of Leicester, Leicester, United Kingdom
| | - Robert A. Hirst
- Department of Infection, Immunity and Inflammation, Leicester Royal Infirmary, University of Leicester, Leicester, United Kingdom
| | - Jennifer H. Ward
- Children’s Brain Tumour Research Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Chris O’Callaghan
- Department of Respiratory Medicine, Portex Unit, Institute of Child Health, University College London and Great Ormond Street Hospital, London, United Kingdom
| | - Stuart J. Smith
- Children’s Brain Tumour Research Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Malcolm F. G. Stevens
- School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Richard G. Grundy
- Children’s Brain Tumour Research Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Ruman Rahman
- Children’s Brain Tumour Research Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
- * E-mail:
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