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Zeng W, Dou Y, Pan L, Xu L, Peng S. Improving prediction performance of general protein language model by domain-adaptive pretraining on DNA-binding protein. Nat Commun 2024; 15:7838. [PMID: 39244557 PMCID: PMC11380688 DOI: 10.1038/s41467-024-52293-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 08/29/2024] [Indexed: 09/09/2024] Open
Abstract
DNA-protein interactions exert the fundamental structure of many pivotal biological processes, such as DNA replication, transcription, and gene regulation. However, accurate and efficient computational methods for identifying these interactions are still lacking. In this study, we propose a method ESM-DBP through refining the DNA-binding protein sequence repertory and domain-adaptive pretraining based the general protein language model. Our method considers the lacking exploration of general language model for DNA-binding protein domain-specific knowledge, so we screen out 170,264 DNA-binding protein sequences to construct the domain-adaptive language model. Experimental results on four downstream tasks show that ESM-DBP provides a better feature representation of DNA-binding protein compared to the original language model, resulting in improved prediction performance and outperforming the state-of-the-art methods. Moreover, ESM-DBP can still perform well even for those sequences with only a few homologous sequences. ChIP-seq on two predicted cases further support the validity of the proposed method.
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Affiliation(s)
- Wenwu Zeng
- College of Computer Science and Electronic Engineering, Hunan University, Changsha, 410082, China
| | - Yutao Dou
- College of Computer Science and Electronic Engineering, Hunan University, Changsha, 410082, China
| | - Liangrui Pan
- College of Computer Science and Electronic Engineering, Hunan University, Changsha, 410082, China
| | - Liwen Xu
- College of Computer Science and Electronic Engineering, Hunan University, Changsha, 410082, China.
| | - Shaoliang Peng
- College of Computer Science and Electronic Engineering, Hunan University, Changsha, 410082, China.
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2
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Bonchuk AN, Georgiev PG. C2H2 proteins: Evolutionary aspects of domain architecture and diversification. Bioessays 2024; 46:e2400052. [PMID: 38873893 DOI: 10.1002/bies.202400052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 06/15/2024]
Abstract
The largest group of transcription factors in higher eukaryotes are C2H2 proteins, which contain C2H2-type zinc finger domains that specifically bind to DNA. Few well-studied C2H2 proteins, however, demonstrate their key role in the control of gene expression and chromosome architecture. Here we review the features of the domain architecture of C2H2 proteins and the likely origin of C2H2 zinc fingers. A comprehensive investigation of proteomes for the presence of proteins with multiple clustered C2H2 domains has revealed a key difference between groups of organisms. Unlike plants, transcription factors in metazoans contain clusters of C2H2 domains typically separated by a linker with the TGEKP consensus sequence. The average size of C2H2 clusters varies substantially, even between genomes of higher metazoans, and with a tendency to increase in combination with SCAN, and especially KRAB domains, reflecting the increasing complexity of gene regulatory networks.
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Affiliation(s)
- Artem N Bonchuk
- Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Pavel G Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
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3
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Rodriguez J, Battistini F, Learte-Aymamí S, Orozco M, Mascareñas JL. Molecular dynamics modelling of the interaction of a synthetic zinc-finger miniprotein with DNA. RSC Chem Biol 2023; 4:486-493. [PMID: 37415868 PMCID: PMC10320839 DOI: 10.1039/d3cb00053b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 05/09/2023] [Indexed: 07/08/2023] Open
Abstract
We report the modelling of the DNA complex of an artificial miniprotein composed of two zinc finger modules and an AT-hook linking peptide. The computational study provides for the first time a structural view of these types of complexes, dissecting interactions that are key to modulate their stability. The relevance of these interactions was validated experimentally. These results confirm the potential of this type of computational approach for studying peptide-DNA complexes and suggest that they could be very useful for the rational design of non-natural, DNA binding miniproteins.
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Affiliation(s)
- Jessica Rodriguez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), and Departamento de Química Orgánica, Universidade de Santiago de Compostela Rúa Jenaro de la Fuente s/n 15782 Santiago de Compostela Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST) Baldiri Reixac 10-12 08028 Barcelona Spain
| | - Federica Battistini
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST) Baldiri Reixac 10-12 08028 Barcelona Spain
- Department of Biochemistry and Molecular Biology, University of Barcelona 08028 Barcelona Spain
| | - Soraya Learte-Aymamí
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), and Departamento de Química Orgánica, Universidade de Santiago de Compostela Rúa Jenaro de la Fuente s/n 15782 Santiago de Compostela Spain
| | - Modesto Orozco
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST) Baldiri Reixac 10-12 08028 Barcelona Spain
- Department of Biochemistry and Molecular Biology, University of Barcelona 08028 Barcelona Spain
| | - José L Mascareñas
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), and Departamento de Química Orgánica, Universidade de Santiago de Compostela Rúa Jenaro de la Fuente s/n 15782 Santiago de Compostela Spain
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4
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The nanoCUT&RUN technique visualizes telomeric chromatin in Drosophila. PLoS Genet 2022; 18:e1010351. [PMID: 36048878 PMCID: PMC9473618 DOI: 10.1371/journal.pgen.1010351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 09/14/2022] [Accepted: 07/21/2022] [Indexed: 11/19/2022] Open
Abstract
Advances in genomic technology led to a more focused pattern for the distribution of chromosomal proteins and a better understanding of their functions. The recent development of the CUT&RUN technique marks one of the important such advances. Here we develop a modified CUT&RUN technique that we termed nanoCUT&RUN, in which a high affinity nanobody to GFP is used to bring micrococcal nuclease to the binding sites of GFP-tagged chromatin proteins. Subsequent activation of the nuclease cleaves the chromatin, and sequencing of released DNA identifies binding sites. We show that nanoCUT&RUN efficiently produces high quality data for the TRL transcription factor in Drosophila embryos, and distinguishes binding sites specific between two TRL isoforms. We further show that nanoCUT&RUN dissects the distributions of the HipHop and HOAP telomere capping proteins, and uncovers unexpected binding of telomeric proteins at centromeres. nanoCUT&RUN can be readily applied to any system in which a chromatin protein of interest, or its isoforms, carries the GFP tag. The method of chromatin immunoprecipitation followed by genomic sequencing (ChIP-seq) has been employed to study the distribution of chromatin binding proteins genome-wide. Such studies have greatly enhanced our understanding of the function of the target proteins. However, the uses of chemical crosslinking combined with the procedure of antibody-medicated precipitation of the protein-DNA complex have limited the efficiency of ChIP-seq. The recently developed CUT&RUN method has greatly improved that efficiency. We here developed the “nanoCUT&RUN” extension of CUT&RUN, which can be readily applied to any target protein with a GFP tag. Using nanoCUT&RUN, we profiled the HipHop and HOAP proteins that protect telomeric chromatin in Drosophila. We uncovered sequence-independent binding of both proteins predominantly to telomeres. Interestingly, HipHop binding can also be detected at centromeric chromatin suggestive of a novel function of a telomere capping protein.
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Shi WT, Zhang B, Li ML, Liu KH, Jiao J, Tian CF. The convergent xenogeneic silencer MucR predisposes α-proteobacteria to integrate AT-rich symbiosis genes. Nucleic Acids Res 2022; 50:8580-8598. [PMID: 36007892 PMCID: PMC9410896 DOI: 10.1093/nar/gkac664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 07/11/2022] [Accepted: 07/21/2022] [Indexed: 11/16/2022] Open
Abstract
Bacterial adaptation is largely shaped by horizontal gene transfer, xenogeneic silencing mediated by lineage-specific DNA bridgers (H-NS, Lsr2, MvaT and Rok), and various anti-silencing mechanisms. No xenogeneic silencing DNA bridger is known for α-proteobacteria, from which mitochondria evolved. By investigating α-proteobacterium Sinorhizobium fredii, a facultative legume microsymbiont, here we report the conserved zinc-finger bearing MucR as a novel xenogeneic silencing DNA bridger. Self-association mediated by its N-terminal domain (NTD) is required for DNA–MucR–DNA bridging complex formation, maximizing MucR stability, transcriptional silencing, and efficient symbiosis in legume nodules. Essential roles of NTD, CTD (C-terminal DNA-binding domain), or full-length MucR in symbiosis can be replaced by non-homologous NTD, CTD, or full-length protein of H-NS from γ-proteobacterium Escherichia coli, while NTD rather than CTD of Lsr2 from Gram-positive Mycobacterium tuberculosis can replace the corresponding domain of MucR in symbiosis. Chromatin immunoprecipitation sequencing reveals similar recruitment profiles of H-NS, MucR and various functional chimeric xenogeneic silencers across the multipartite genome of S. fredii, i.e. preferring AT-rich genomic islands and symbiosis plasmid with key symbiosis genes as shared targets. Collectively, the convergently evolved DNA bridger MucR predisposed α-proteobacteria to integrate AT-rich foreign DNA including symbiosis genes, horizontal transfer of which is strongly selected in nature.
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Affiliation(s)
- Wen-Tao Shi
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University , Beijing , China
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research Center, China Agricultural University , Beijing , China
| | - Biliang Zhang
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University , Beijing , China
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research Center, China Agricultural University , Beijing , China
| | - Meng-Lin Li
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University , Beijing , China
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research Center, China Agricultural University , Beijing , China
| | - Ke-Han Liu
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University , Beijing , China
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research Center, China Agricultural University , Beijing , China
| | - Jian Jiao
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University , Beijing , China
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research Center, China Agricultural University , Beijing , China
| | - Chang-Fu Tian
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University , Beijing , China
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research Center, China Agricultural University , Beijing , China
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Zhang X, Guo Q, Qin L, Li L. A Cys2His2 Zinc Finger Transcription Factor BpSZA1 Positively Modulates Salt Stress in Betula platyphylla. FRONTIERS IN PLANT SCIENCE 2022; 13:823547. [PMID: 35693173 PMCID: PMC9174930 DOI: 10.3389/fpls.2022.823547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 03/29/2022] [Indexed: 05/07/2023]
Abstract
Zinc finger proteins (ZFPs) are widely involved in plant growth and abiotic stress responses, however, few of these proteins have been functionally characterized in tree species. In this study, we cloned and characterized the BpSZA1 gene encoding a C2H2-type ZFP from Betula platyphylla. BpSZA1 is a transcription factor localized in the nucleus, with a transcription activation domain located at the N-terminus. BpSZA1 was predominantly expressed in stems and was induced by salt. We generated transgenic birch lines displaying overexpression (OE) or RNAi silencing (Ri) of BpSZA1 and exposed these along with wild-type birch seedlings to salinity. Phenotypic and physiological parameters such as superoxide dismutase, peroxisome, H2O2 content, proline content, water loss rate, and malondialdehyde content were examined. Overexpression of BpSZA1 in birch conferred increased salt tolerance. Chromatin immunoprecipitation-qPCR and RNA-seq showed that BpSZA1 binds to the GAGA-motif in the promoter of downstream target genes including BpAPX1, BpAPX2, BpCAT, and Bp6PGDH to activate their transcription. BpSZA1 also participates in abscisic acid (ABA) biosynthesis, proline biosynthesis, and the ABA/jasmonic acid pathway to enhance the salt stress of B. platyphylla.
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7
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Chetverina D, Erokhin M, Schedl P. GAGA factor: a multifunctional pioneering chromatin protein. Cell Mol Life Sci 2021; 78:4125-4141. [PMID: 33528710 DOI: 10.1007/s00018-021-03776-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 12/08/2020] [Accepted: 01/19/2021] [Indexed: 12/27/2022]
Abstract
The Drosophila GAGA factor (GAF) is a multifunctional protein implicated in nucleosome organization and remodeling, activation and repression of gene expression, long distance enhancer-promoter communication, higher order chromosome structure, and mitosis. This broad range of activities poses questions about how a single protein can perform so many seemingly different and unrelated functions. Current studies argue that GAF acts as a "pioneer" factor, generating nucleosome-free regions of chromatin for different classes of regulatory elements. The removal of nucleosomes from regulatory elements in turn enables other factors to bind to these elements and carry out their specialized functions. Consistent with this view, GAF associates with a collection of chromatin remodelers and also interacts with proteins implicated in different regulatory functions. In this review, we summarize the known activities of GAF and the functions of its protein partners.
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Affiliation(s)
- Darya Chetverina
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia.
| | - Maksim Erokhin
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia
| | - Paul Schedl
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
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8
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Rodríguez J, Learte-Aymamí S, Mosquera J, Celaya G, Rodríguez-Larrea D, Vázquez ME, Mascareñas JL. DNA-binding miniproteins based on zinc fingers. Assessment of the interaction using nanopores. Chem Sci 2018; 9:4118-4123. [PMID: 29780541 PMCID: PMC5941273 DOI: 10.1039/c7sc05441f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 03/23/2018] [Indexed: 12/18/2022] Open
Abstract
We report a synthetic miniprotein that combines zinc finger modules of the transcription factor GAGA with the AT-hook peptide. This designed chimera binds to extended DNA sites with high affinity and selectivity, as shown by nanopore force spectroscopy.
Obtaining artificial proteins that mimic the DNA binding properties of natural transcription factors could open new ways of manipulating gene expression at will. In this context it is particularly interesting to develop simple synthetic systems. Inspired by the modularity of natural transcription factors, we have designed synthetic miniproteins that combine the zinc finger module of the transcription factor GAGA and AT-hook peptide domains. These constructs are capable of binding to composite DNA sequences of up to 14 base pairs with high affinity and good selectivity. In particular, we have synthesized three different chimeras and characterized their DNA binding properties by electrophoresis and fluorescence anisotropy. We have also used, for the first time in the study of peptide-based DNA binders, nanopore force spectroscopy to obtain further data on the DNA interaction.
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Affiliation(s)
- Jéssica Rodríguez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) , Departamento de Química Orgánica , Universidade de Santiago de Compostela , 15782 Santiago de Compostela , Spain .
| | - Soraya Learte-Aymamí
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) , Departamento de Química Orgánica , Universidade de Santiago de Compostela , 15782 Santiago de Compostela , Spain .
| | - Jesús Mosquera
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) , Departamento de Química Orgánica , Universidade de Santiago de Compostela , 15782 Santiago de Compostela , Spain .
| | - Garbiñe Celaya
- Biofisika Institute (CSIC, UPV/EHU) , Department of Biochemistry and Molecular Biology (UPV/EHU) , Leioa 48940 , Spain
| | - David Rodríguez-Larrea
- Biofisika Institute (CSIC, UPV/EHU) , Department of Biochemistry and Molecular Biology (UPV/EHU) , Leioa 48940 , Spain
| | - M Eugenio Vázquez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) , Departamento de Química Orgánica , Universidade de Santiago de Compostela , 15782 Santiago de Compostela , Spain .
| | - José L Mascareñas
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) , Departamento de Química Orgánica , Universidade de Santiago de Compostela , 15782 Santiago de Compostela , Spain .
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9
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Liu N, Hargreaves VV, Zhu Q, Kurland JV, Hong J, Kim W, Sher F, Macias-Trevino C, Rogers JM, Kurita R, Nakamura Y, Yuan GC, Bauer DE, Xu J, Bulyk ML, Orkin SH. Direct Promoter Repression by BCL11A Controls the Fetal to Adult Hemoglobin Switch. Cell 2018; 173:430-442.e17. [PMID: 29606353 DOI: 10.1016/j.cell.2018.03.016] [Citation(s) in RCA: 297] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 01/16/2018] [Accepted: 03/06/2018] [Indexed: 01/06/2023]
Abstract
Fetal hemoglobin (HbF, α2γ2) level is genetically controlled and modifies severity of adult hemoglobin (HbA, α2β2) disorders, sickle cell disease, and β-thalassemia. Common genetic variation affects expression of BCL11A, a regulator of HbF silencing. To uncover how BCL11A supports the developmental switch from γ- to β- globin, we use a functional assay and protein binding microarray to establish a requirement for a zinc-finger cluster in BCL11A in repression and identify a preferred DNA recognition sequence. This motif appears in embryonic and fetal-expressed globin promoters and is duplicated in γ-globin promoters. The more distal of the duplicated motifs is mutated in individuals with hereditary persistence of HbF. Using the CUT&RUN approach to map protein binding sites in erythroid cells, we demonstrate BCL11A occupancy preferentially at the distal motif, which can be disrupted by editing the promoter. Our findings reveal that direct γ-globin gene promoter repression by BCL11A underlies hemoglobin switching.
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Affiliation(s)
- Nan Liu
- Cancer and Blood Disorders Center, Dana Farber Cancer Institute and Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Victoria V Hargreaves
- Cancer and Blood Disorders Center, Dana Farber Cancer Institute and Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Qian Zhu
- Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute and Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Jesse V Kurland
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jiyoung Hong
- Cancer and Blood Disorders Center, Dana Farber Cancer Institute and Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Woojin Kim
- Cancer and Blood Disorders Center, Dana Farber Cancer Institute and Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Falak Sher
- Cancer and Blood Disorders Center, Dana Farber Cancer Institute and Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Claudio Macias-Trevino
- Cancer and Blood Disorders Center, Dana Farber Cancer Institute and Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Julia M Rogers
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Committee on Higher Degrees in Biophysics, Harvard University, Cambridge, MA, USA
| | - Ryo Kurita
- Cell Engineering Division, RIKEN Bioresource Center, Tsukuba, Japan
| | - Yukio Nakamura
- Cell Engineering Division, RIKEN Bioresource Center, Tsukuba, Japan
| | - Guo-Cheng Yuan
- Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute and Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Daniel E Bauer
- Cancer and Blood Disorders Center, Dana Farber Cancer Institute and Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jian Xu
- Children's Medical Center Research Institute, Department of Pediatrics, University of Texas at Southwestern Medical Center, Dallas, TX, USA
| | - Martha L Bulyk
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Committee on Higher Degrees in Biophysics, Harvard University, Cambridge, MA, USA; Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Stuart H Orkin
- Cancer and Blood Disorders Center, Dana Farber Cancer Institute and Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Howard Hughes Medical Institute, Boston, MA, USA.
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Moghaddas Sani H, Hamzeh-Mivehroud M, Silva AP, Walshe JL, Mohammadi SA, Rahbar-Shahrouziasl M, Abbasi M, Jamshidi O, Low JKK, Dastmalchi S, Mackay JP. Expression, purification and DNA-binding properties of zinc finger domains of DOF proteins from Arabidopsis thaliana. BIOIMPACTS : BI 2018; 8:167-176. [PMID: 30211076 PMCID: PMC6128974 DOI: 10.15171/bi.2018.19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 01/22/2018] [Indexed: 01/14/2023]
Abstract
Introduction: DOF proteins are a family of plant-specific transcription factors with a conserved zinc finger (ZF) DNA-binding domain. Although several studies have demonstrated their specific DNA binding, quantitative affinity data is not available for the binding of DOF domains to their binding sites. Methods: ZF domains of DOF2.1, DOF3.4, and DOF5.8 from Arabidopsis thaliana were expressed and purified. Their DNA binding affinities were assessed using gel retardation assays and microscale thermophoresis with two different oligonucleotide probes containing one and two copies of recognition sequence AAAG. Results: DOF zinc finger domains (DOF-ZFs) were shown to form independently folded structures. Assessments using microscale thermophoresis demonstrated that DOF-ZFs interact more tightly (~ 100 fold) with double-motif probe than the single-motif probe. The overall Kd values for the DOF3.4-ZF and DOF5.8-ZF to the double-motif probe were ~2.3±1 and 2.5±1 µM, respectively. Conclusion: Studied DOF-ZF domains formed stable complexes with the double-motif probe. Although DOF3.4-ZF and DOF5.8-ZF do not dimerize with an appreciable affinity in the absence of DNA (judging from size-exclusion and multiangle laser light scattering data), it is possible that these ZFs form protein-protein contacts when bound to this oligonucleotide, consistent with previous reports that DOF proteins can homo- and hetero-dimerize.
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Affiliation(s)
- Hakimeh Moghaddas Sani
- Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Maryam Hamzeh-Mivehroud
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- School of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ana P. Silva
- School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | - James L. Walshe
- School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | | | | | - Milad Abbasi
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Omid Jamshidi
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Jason KK Low
- School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | - Siavoush Dastmalchi
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- School of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
- Faculty of Pharmacy, Near East University, POBOX:99138, Nicosia, North Cyprus, Mersin 10, Turkey
| | - Joel P. Mackay
- School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
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11
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Blixt MKE, Konjusha D, Ring H, Hallböök F. Zinc finger gene nolz1 regulates the formation of retinal progenitor cells and suppresses the Lim3/Lhx3 phenotype of retinal bipolar cells in chicken retina. Dev Dyn 2017; 247:630-641. [PMID: 29139167 DOI: 10.1002/dvdy.24607] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 09/29/2017] [Accepted: 10/17/2017] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The zinc-finger transcription factor Nolz1 regulates spinal cord neuron development by interacting with the transcription factors Isl1, Lim1, and Lim3, which are also important for photoreceptors, horizontal and bipolar cells during retinal development. We, therefore, studied Nolz1 during retinal development. RESULTS Nolz1 expression was seen in two waves during development: one early (peak at embryonic day 3-4.5) in retinal progenitors and one late (embryonic day 8) in newly differentiated cells in the inner nuclear layer. Overexpression and knockdown showed that Nolz1 decreases proliferation and stimulates cell cycle withdrawal in retinal progenitors with effects on the generation of retinal ganglion cells, photoreceptors, and horizontal cells without triggering apoptosis. Overexpression of Nolz1 gave more p27 positive cells. Sustained overexpression of Nolz1 in the retina gave fewer Lim3/Lhx3 bipolar cells. CONCLUSIONS We conclude that Nolz1 has multiple functions during development and suggest a mechanism in which Nolz1 initially regulates the proliferation state of the retinal progenitor cells and then acts as a repressor that suppresses the Lim3/Lhx3 bipolar cell phenotype at the time of bipolar cell differentiation. Developmental Dynamics 247:630-641, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Maria K E Blixt
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Dardan Konjusha
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Henrik Ring
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Finn Hallböök
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
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12
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Ghosh S, Chatterji D. Two zinc finger proteins from Mycobacterium smegmatis: DNA binding and activation of transcription. Genes Cells 2017. [PMID: 28639742 DOI: 10.1111/gtc.12507] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Single zinc finger domain containing proteins are very few in number. Of numerous zinc finger proteins in eukaryotes, only three of them like GAGA, Superman and DNA binding by one finger (Dof) have single zinc finger domain. Although few zinc finger proteins have been described in eubacteria, no protein with single C4 zinc finger has been described in details in anyone of them. In this article, we are describing two novel C-terminal C4 zinc finger proteins-Msmeg_0118 and Msmeg_3613 from Mycobacterium smegmatis. We have named these proteins as Mszfp1 (Mycobacterial Single Zinc Finger Protein 1) and Mszfp2 (Mycobacterial Single Zinc Finger Protein 2). Both the proteins are expressed constitutively, can bind to DNA and regulate transcription. It appears that Mszfp1 and Mszfp2 may activate transcription by interacting with RNA polymerase.
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Affiliation(s)
- Subho Ghosh
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Dipankar Chatterji
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
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13
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In-depth study of DNA binding of Cys2His2 finger domains in testis zinc-finger protein. PLoS One 2017; 12:e0175051. [PMID: 28384299 PMCID: PMC5383199 DOI: 10.1371/journal.pone.0175051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/20/2017] [Indexed: 11/26/2022] Open
Abstract
Previously, we identified that both fingers 1 and 2 in the three Cys2His2 zinc-finger domains (TZD) of testis zinc-finger protein specifically bind to its cognate DNA; however, finger 3 is non-sequence–specific. To gain insights into the interaction mechanism, here we further investigated the DNA-binding characteristics of TZD bound to non-specific DNAs and its finger segments bound to cognate DNA. TZD in non-specific DNA binding showed smaller chemical shift perturbations, as expected. However, the direction of shift perturbation, change of DNA imino-proton NMR signal, and dynamics on the 15N backbone atom significantly differed between specific and non-specific binding. Using these unique characteristics, we confirmed that the three single-finger segments (TZD1, TZD2 and TZD3) and the two-finger segment (TZD23) non-specifically bind to the cognate DNA. In comparison, the other two-finger segment (TZD12) binding to the cognate DNA features simultaneous non-specific and semi-specific binding, both slowly exchanged in terms of NMR timescale. The process of TZD binding to the cognate DNA is likely stepwise: initially TZD non-specifically binds to DNA, then fingers 1 and 2 insert cooperatively into the major groove of DNA by semi-specific binding, and finally finger 3 non-specifically binds to DNA, which promotes the specific binding on fingers 1 and 2 and stabilizes the formation of a specific TZD–DNA complex.
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14
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Lomaev D, Mikhailova A, Erokhin M, Shaposhnikov AV, Moresco JJ, Blokhina T, Wolle D, Aoki T, Ryabykh V, Yates JR, Shidlovskii YV, Georgiev P, Schedl P, Chetverina D. The GAGA factor regulatory network: Identification of GAGA factor associated proteins. PLoS One 2017; 12:e0173602. [PMID: 28296955 PMCID: PMC5351981 DOI: 10.1371/journal.pone.0173602] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 02/23/2017] [Indexed: 11/24/2022] Open
Abstract
The Drosophila GAGA factor (GAF) has an extraordinarily diverse set of functions that include the activation and silencing of gene expression, nucleosome organization and remodeling, higher order chromosome architecture and mitosis. One hypothesis that could account for these diverse activities is that GAF is able to interact with partners that have specific and dedicated functions. To test this possibility we used affinity purification coupled with high throughput mass spectrometry to identify GAF associated partners. Consistent with this hypothesis the GAF interacting network includes a large collection of factors and complexes that have been implicated in many different aspects of gene activity, chromosome structure and function. Moreover, we show that GAF interactions with a small subset of partners is direct; however for many others the interactions could be indirect, and depend upon intermediates that serve to diversify the functional capabilities of the GAF protein.
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Affiliation(s)
- Dmitry Lomaev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Anna Mikhailova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Maksim Erokhin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | | | - James J. Moresco
- Department of Chemical Physiology, SR302B, The Scripps Research Institute, La Jolla, California, United States of America
| | - Tatiana Blokhina
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Daniel Wolle
- Department of Molecular Biology Princeton University, Princeton, NJ, United States of America
| | - Tsutomu Aoki
- Department of Molecular Biology Princeton University, Princeton, NJ, United States of America
| | - Vladimir Ryabykh
- Institute of Animal Physiology, Biochemistry and Nutrition, Borovsk, Russia
| | - John R. Yates
- Department of Chemical Physiology, SR302B, The Scripps Research Institute, La Jolla, California, United States of America
| | | | - Pavel Georgiev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- * E-mail: (DC); (PS); (PG)
| | - Paul Schedl
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- Department of Molecular Biology Princeton University, Princeton, NJ, United States of America
- * E-mail: (DC); (PS); (PG)
| | - Darya Chetverina
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- * E-mail: (DC); (PS); (PG)
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15
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The quest for mammalian Polycomb response elements: are we there yet? Chromosoma 2015; 125:471-96. [PMID: 26453572 PMCID: PMC4901126 DOI: 10.1007/s00412-015-0539-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 08/31/2015] [Accepted: 09/02/2015] [Indexed: 12/12/2022]
Abstract
A long-standing mystery in the field of Polycomb and Trithorax regulation is how these proteins, which are highly conserved between flies and mammals, can regulate several hundred equally highly conserved target genes, but recognise these targets via cis-regulatory elements that appear to show no conservation in their DNA sequence. These elements, termed Polycomb/Trithorax response elements (PRE/TREs or PREs), are relatively well characterised in flies, but their mammalian counterparts have proved to be extremely difficult to identify. Recent progress in this endeavour has generated a wealth of data and raised several intriguing questions. Here, we ask why and to what extent mammalian PREs are so different to those of the fly. We review recent advances, evaluate current models and identify open questions in the quest for mammalian PREs.
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16
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Malgieri G, Palmieri M, Russo L, Fattorusso R, Pedone PV, Isernia C. The prokaryotic zinc-finger: structure, function and comparison with the eukaryotic counterpart. FEBS J 2015; 282:4480-96. [PMID: 26365095 DOI: 10.1111/febs.13503] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 07/23/2015] [Accepted: 08/24/2015] [Indexed: 01/18/2023]
Abstract
Classical zinc finger (ZF) domains were thought to be confined to the eukaryotic kingdom until the transcriptional regulator Ros protein was identified in Agrobacterium tumefaciens. The Ros Cys2 His2 ZF binds DNA in a peculiar mode and folds in a domain significantly larger than its eukaryotic counterpart consisting of 58 amino acids (the 9-66 region) arranged in a βββαα topology, and stabilized by a conserved, extensive, 15-residue hydrophobic core. The prokaryotic ZF domain, then, shows some intriguing new features that make it interestingly different from its eukaryotic counterpart. This review will focus on the prokaryotic ZFs, summarizing and discussing differences and analogies with the eukaryotic domains and providing important insights into their structure/function relationships.
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Affiliation(s)
- Gaetano Malgieri
- Department of Environmental, Biological and Pharmaceutical Science and Technology, II University of Naples, Caserta, Italy
| | - Maddalena Palmieri
- Department of Environmental, Biological and Pharmaceutical Science and Technology, II University of Naples, Caserta, Italy
| | - Luigi Russo
- Department of Environmental, Biological and Pharmaceutical Science and Technology, II University of Naples, Caserta, Italy
| | - Roberto Fattorusso
- Department of Environmental, Biological and Pharmaceutical Science and Technology, II University of Naples, Caserta, Italy.,Interuniversity Research Centre on Bioactive Peptides, University of Naples 'Federico II', Naples, Italy
| | - Paolo V Pedone
- Department of Environmental, Biological and Pharmaceutical Science and Technology, II University of Naples, Caserta, Italy.,Interuniversity Research Centre on Bioactive Peptides, University of Naples 'Federico II', Naples, Italy
| | - Carla Isernia
- Department of Environmental, Biological and Pharmaceutical Science and Technology, II University of Naples, Caserta, Italy.,Interuniversity Research Centre on Bioactive Peptides, University of Naples 'Federico II', Naples, Italy
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17
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Negi S, Terada Y, Suzuyama M, Matsumoto H, Honbo A, Amagase Y, Mizukawa Y, Kiriyama A, Iga K, Urushidaini T, Sugiura Y. Intrinsic cell permeability of the GAGA zinc finger protein into HeLa cells. Biochem Biophys Res Commun 2015; 464:1034-1039. [PMID: 26187668 DOI: 10.1016/j.bbrc.2015.07.060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 07/11/2015] [Indexed: 11/30/2022]
Abstract
We examined the intrinsic cell permeability of a GAGA zinc finger obtained from the Drosophila melanogaster transcription factor and analyzed its mechanism of cellular uptake using confocal microscopy and flow cytometry. HeLa cells were treated with the Cy5-labeld GAGA peptides (containing a fluorescent chromophore) to detect fluorescence signals from the fluorescent labeling peptides by confocal microscopy. The results clearly indicated that GAGA peptides possess intrinsic cell permeability for HeLa cells. Based on the results of the flow cytometry analysis and the theoretical net positive charge of the GAGA peptides, the efficiency of cellular uptake of the GAGA peptides was predicted to depend on the net positive charge of the GAGA peptide as well as the cationic component ratio of Arg residues to Lys residues.
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Affiliation(s)
- Shigeru Negi
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto, 610-0395, Japan.
| | - Yuka Terada
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto, 610-0395, Japan
| | - Misato Suzuyama
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto, 610-0395, Japan
| | - Haruka Matsumoto
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto, 610-0395, Japan
| | - Akino Honbo
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto, 610-0395, Japan
| | - Yoko Amagase
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto, 610-0395, Japan
| | - Yumiko Mizukawa
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto, 610-0395, Japan
| | - Akiko Kiriyama
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto, 610-0395, Japan
| | - Katsumi Iga
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto, 610-0395, Japan
| | - Tetsuro Urushidaini
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto, 610-0395, Japan
| | - Yukio Sugiura
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto, 610-0395, Japan
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18
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Rodríguez J, Mosquera J, Couceiro JR, Vázquez ME, Mascareñas JL. The AT-Hook motif as a versatile minor groove anchor for promoting DNA binding of transcription factor fragments. Chem Sci 2015; 6:4767-4771. [PMID: 26290687 PMCID: PMC4538796 DOI: 10.1039/c5sc01415h] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 05/22/2015] [Indexed: 12/19/2022] Open
Abstract
We report the development of chimeric DNA binding peptides comprising a DNA binding fragment of natural transcription factors (the basic region of a bZIP protein or a monomeric zinc finger module) and an AT-Hook peptide motif. The resulting peptide conjugates display high DNA affinity and excellent sequence selectivity. Furthermore, the AT-Hook motif also favors the cell internalization of the conjugates.
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Affiliation(s)
- Jéssica Rodríguez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) , Departamento de Química Orgánica , Universidade de Santiago de Compostela , 15782 Santiago de Compostela , Spain . ; Fax: +34 981 595 012 ; Tel: +34 981 576541 ext. 14405
| | - Jesús Mosquera
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) , Departamento de Química Orgánica , Universidade de Santiago de Compostela , 15782 Santiago de Compostela , Spain . ; Fax: +34 981 595 012 ; Tel: +34 981 576541 ext. 14405
| | - Jose R. Couceiro
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) , Departamento de Química Orgánica , Universidade de Santiago de Compostela , 15782 Santiago de Compostela , Spain . ; Fax: +34 981 595 012 ; Tel: +34 981 576541 ext. 14405
| | - M. Eugenio Vázquez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) , Departamento de Química Orgánica , Universidade de Santiago de Compostela , 15782 Santiago de Compostela , Spain . ; Fax: +34 981 595 012 ; Tel: +34 981 576541 ext. 14405
| | - José L. Mascareñas
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) , Departamento de Química Orgánica , Universidade de Santiago de Compostela , 15782 Santiago de Compostela , Spain . ; Fax: +34 981 595 012 ; Tel: +34 981 576541 ext. 14405
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19
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Fuda NJ, Guertin MJ, Sharma S, Danko CG, Martins AL, Siepel A, Lis JT. GAGA factor maintains nucleosome-free regions and has a role in RNA polymerase II recruitment to promoters. PLoS Genet 2015; 11:e1005108. [PMID: 25815464 PMCID: PMC4376892 DOI: 10.1371/journal.pgen.1005108] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 02/26/2015] [Indexed: 11/28/2022] Open
Abstract
Previous studies have shown that GAGA Factor (GAF) is enriched on promoters with paused RNA Polymerase II (Pol II), but its genome-wide function and mechanism of action remain largely uncharacterized. We assayed the levels of transcriptionally-engaged polymerase using global run-on sequencing (GRO-seq) in control and GAF-RNAi Drosophila S2 cells and found promoter-proximal polymerase was significantly reduced on a large subset of paused promoters where GAF occupancy was reduced by knock down. These promoters show a dramatic increase in nucleosome occupancy upon GAF depletion. These results, in conjunction with previous studies showing that GAF directly interacts with nucleosome remodelers, strongly support a model where GAF directs nucleosome displacement at the promoter and thereby allows the entry Pol II to the promoter and pause sites. This action of GAF on nucleosomes is at least partially independent of paused Pol II because intergenic GAF binding sites with little or no Pol II also show GAF-dependent nucleosome displacement. In addition, the insulator factor BEAF, the BEAF-interacting protein Chriz, and the transcription factor M1BP are strikingly enriched on those GAF-associated genes where pausing is unaffected by knock down, suggesting insulators or the alternative promoter-associated factor M1BP protect a subset of GAF-bound paused genes from GAF knock-down effects. Thus, GAF binding at promoters can lead to the local displacement of nucleosomes, but this activity can be restricted or compensated for when insulator protein or M1BP complexes also reside at GAF bound promoters. Transcriptional regulation is critical for proper gene expression in response to environmental changes and developmental programs. Eukaryotes have evolved multiple mechanisms by which transcription factors regulate transcription. One mechanism is the reorganization of chromatin to allow Pol II recruitment. Another is the release of promoter-proximal paused Pol II, where Pol II transcription that is halted 20–60 bases downstream of the transcription start site (TSS) is allowed to enter into productive elongation through the gene body. The Drosophila transcription factor GAF binds to genes that undergo pausing and interacts with nucleosome remodelers and the pausing factor NELF. Thus, GAF can regulate multiple points necessary for transcription, but its mechanistic role is not fully understood genome-wide. We depleted GAF from cells and examined the genome-wide changes in Pol II and nucleosome distributions across genes. We found that GAF depletion reduces polymerase density at genes where GAF binds just upstream of the TSS, and results in nucleosomes moving into the promoter region. Our results show that GAF is important for maintaining the promoter accessibility, allowing Pol II to be recruited to promoters and enter the pause sites downstream of the TSS. Thus, GAF is critical for providing the chromatin environment necessary for the proper control of gene expression.
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Affiliation(s)
- Nicholas J. Fuda
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Michael J. Guertin
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Sumeet Sharma
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Charles G. Danko
- Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, New York, United States of America
| | - André L. Martins
- Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, New York, United States of America
| | - Adam Siepel
- Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, New York, United States of America
| | - John T. Lis
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
- * E-mail:
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20
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Blanch M, Piñeyro D, Bernués J. New insights for Drosophila GAGA factor in larvae. ROYAL SOCIETY OPEN SCIENCE 2015; 2:150011. [PMID: 26064623 PMCID: PMC4448821 DOI: 10.1098/rsos.150011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 02/17/2015] [Indexed: 06/04/2023]
Abstract
GAGA factor plays important roles during Drosophila embryogenesis and its maternal contribution is essential for early development. Here, the role of GAGA factor was studied in 3rd instar larvae using depletion and overexpression conditions in wing disc and transcriptome analysis. We found that genes changing expression were different to those previously described using GAGA mutants in embryos. No apparent phenotypes on GAGA depletion could usually be observed at larval stages in imaginal discs but a strong effect on salivary gland polytene chromosomes was observed. In the adult, GAGA depletion produced many defects like abnormal cell proliferation in the wing, impaired dorsal closure and resulted in homeotic transformation of abdominal segment A5. Unexpectedly, no effects on Ultrabithorax expression were observed. Short overexpression of GAGA factor in 3rd instar larvae also resulted in activation of a set of genes not previously described to be under GAGA regulation, and in lethality at pupa. Our results suggest a little contribution of GAGA factor on gene transcription in wing discs and a change of the genes regulated in comparison with embryo. GAGA factor activity thus correlates with the global changes in gene expression that take place at the embryo-to-larva and, later, at the larva-to-pupa transitions.
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Affiliation(s)
- Marta Blanch
- Departament de Genòmica Molecular, Institut de Biologia Molecular de Barcelona-CSIC, Parc Científic de Barcelona, Barcelona 08028, Spain
- Cell and Developmental Biology Programme, Institute for Research in Biomedicine, Barcelona, Spain
| | - David Piñeyro
- Departament de Genòmica Molecular, Institut de Biologia Molecular de Barcelona-CSIC, Parc Científic de Barcelona, Barcelona 08028, Spain
- Cell and Developmental Biology Programme, Institute for Research in Biomedicine, Barcelona, Spain
| | - Jordi Bernués
- Departament de Genòmica Molecular, Institut de Biologia Molecular de Barcelona-CSIC, Parc Científic de Barcelona, Barcelona 08028, Spain
- Cell and Developmental Biology Programme, Institute for Research in Biomedicine, Barcelona, Spain
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21
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Phylogenic analysis revealed an expanded C₂H₂-homeobox subfamily and expression profiles of C₂H₂ zinc finger gene family in Verticillium dahliae. Gene 2015; 562:169-79. [PMID: 25725127 DOI: 10.1016/j.gene.2015.02.063] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 02/23/2015] [Indexed: 01/26/2023]
Abstract
C2H2 zinc finger (CZF) proteins are a major class of transcription factors that play crucial roles in fungal growth, development, various stress responses, and virulence. Little genome-wide data is available regarding the roles of CZF proteins in Verticillium dahliae, a destructive pathogen that causes vascular wilt disease in more than 200 plant species. We identified a total of 79 typical CZF genes in V. dahliae. Comparative analysis revealed that four plant pathogenic fungi, V. dahliae, Fusarium oxysporum, Magnaporthe oryzae, and Botrytis cinerea, have comparable numbers of predicted CZF genes with similar characteristics. Phylogenetic analysis identified a C2H2-homeobox subfamily in V. dahliae containing seven genes with similar gene structures. V. dahliae and F. oxysporum (Hypocreomycetidae) have more genes of this subfamily than M. oryzae (Sordariomycetidae) and B. cinerea (Leotiomycetes). Furthermore, gene-expression analysis of the smoke tree wilt fungus V. dahliae strain XS11 using digital gene-expression profiling and RT-qPCR revealed that a number of CZF genes were differentially expressed during microsclerotia formation, nutritional starvation, and simulated in planta conditions. Furthermore, the expression profiles revealed that some CZF genes were overrepresented during multiple stages, indicating that they might play diverse roles. Our results provide useful information concerning the functions of CZF genes in microsclerotia formation, nutritional stress responses, and pathogenicity in V. dahliae, and form a basis for future functional studies of these genes.
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22
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Kochańczyk T, Drozd A, Krężel A. Relationship between the architecture of zinc coordination and zinc binding affinity in proteins – insights into zinc regulation. Metallomics 2015; 7:244-57. [DOI: 10.1039/c4mt00094c] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Relationship between the architecture and stability of zinc proteins.
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Affiliation(s)
- Tomasz Kochańczyk
- Laboratory of Chemical Biology
- Faculty of Biotechnology
- University of Wrocław
- 50-383 Wrocław, Poland
| | - Agnieszka Drozd
- Laboratory of Chemical Biology
- Faculty of Biotechnology
- University of Wrocław
- 50-383 Wrocław, Poland
| | - Artur Krężel
- Laboratory of Chemical Biology
- Faculty of Biotechnology
- University of Wrocław
- 50-383 Wrocław, Poland
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23
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Hess JL, Quinn TP, Akbarian S, Glatt SJ. Bioinformatic analyses and conceptual synthesis of evidence linking ZNF804A to risk for schizophrenia and bipolar disorder. Am J Med Genet B Neuropsychiatr Genet 2015; 168B:14-35. [PMID: 25522715 DOI: 10.1002/ajmg.b.32284] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 11/14/2014] [Indexed: 12/20/2022]
Abstract
Advances in molecular genetics, fueled by the results of large-scale genome-wide association studies, meta-analyses, and mega-analyses, have provided the means of identifying genetic risk factors for human disease, thereby enriching our understanding of the functionality of the genome in the post-genomic era. In the past half-decade, research on neuropsychiatric disorders has reached an important milestone: the identification of susceptibility genes reliably associated with complex psychiatric disorders at genome-wide levels of significance. This age of discovery provides the groundwork for follow-up studies designed to elucidate the mechanism(s) by which genetic variants confer susceptibility to these disorders. The gene encoding zinc-finger protein 804 A (ZNF804A) is among these candidate genes, recently being found to be strongly associated with schizophrenia and bipolar disorder via one of its non-coding mutations, rs1344706. Neurobiological, molecular, and bioinformatic analyses have improved our understanding of ZNF804A in general and this variant in particular; however, more work is needed to establish the mechanism(s) by which ZNF804A variants impinge on the biological substrates of the two disorders. Here, we review literature recently published on ZNF804A, and analyze critical concepts related to the biology of ZNF804A and the role of rs1344706 in schizophrenia and bipolar disorder. We synthesize the results of new bioinformatic analyses of ZNF804A with key elements of the existing literature and knowledge base. Furthermore, we suggest some potentially fruitful short- and long-term research goals in the assessment of ZNF804A.
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Affiliation(s)
- Jonathan L Hess
- Psychiatric Genetic Epidemiology & Neurobiology Laboratory (PsychGENe Lab), Departments of Psychiatry and Behavioral Sciences and Neuroscience and Physiology, SUNY Upstate Medical University, New York City, New York
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24
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Russo L, Palmieri M, Caso JV, D'Abrosca G, Diana D, Malgieri G, Baglivo I, Isernia C, Pedone PV, Fattorusso R. Towards understanding the molecular recognition process in prokaryotic zinc-finger domain. Eur J Med Chem 2014; 91:100-8. [PMID: 25240418 DOI: 10.1016/j.ejmech.2014.09.040] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 09/05/2014] [Accepted: 09/11/2014] [Indexed: 10/24/2022]
Abstract
Eukaryotic Cys2His2 zinc finger domain is one of the most common and important structural motifs involved in protein-DNA interaction. The recognition motif is characterized by the tetrahedral coordination of a zinc ion by conserved cysteine and histidine residues. We have characterized the prokaryotic Cys2His2 zinc finger motif, included in the DNA binding region (Ros87) of Ros protein from Agrobacterium tumefaciens, demonstrating that, although possessing a similar zinc coordination sphere, this domain presents significant differences from its eukaryotic counterpart. Furthermore, basic residues flanking the zinc binding region on either side have been demonstrated, by Electrophoretic Mobility Shift Assay (EMSA) experiments, to be essential for Ros DNA binding. In spite of this wealth of knowledge, the structural details of the mechanism through which the prokaryotic zinc fingers recognize their target genes are still unclear. Here, to gain insights into the molecular DNA recognition process of prokaryotic zinc finger domains we applied a strategy in which we performed molecular docking studies using a combination of Nuclear Magnetic Resonance (NMR) and Molecular Dynamics (MD) simulations data. The results demonstrate that the MD ensemble provides a reasonable picture of Ros87 backbone dynamics in solution. The Ros87-DNA model indicates that the interaction involves the first two residue of the first α-helix, and several residues located in the basic regions flanking the zinc finger domain. Interestingly, the prokaryotic zinc finger domain, mainly with the C-terminal tail that is wrapped around the DNA, binds a more extended recognition site than the eukaryotic counterpart. Our analysis demonstrates that the introduction of the protein flexibility in docking studies can improve, in terms of accuracy, the quality of the obtained models and could be particularly useful for protein showing high conformational heterogeneity as well as for computational drug design applications.
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Affiliation(s)
- Luigi Russo
- Department of Environmental, Biological and Pharmaceutical Sciences and Technology, Via Vivaldi 43, 81100 Caserta, Italy
| | - Maddalena Palmieri
- Department of Environmental, Biological and Pharmaceutical Sciences and Technology, Via Vivaldi 43, 81100 Caserta, Italy
| | - Jolanda Valentina Caso
- Department of Environmental, Biological and Pharmaceutical Sciences and Technology, Via Vivaldi 43, 81100 Caserta, Italy
| | - Gianluca D'Abrosca
- Department of Environmental, Biological and Pharmaceutical Sciences and Technology, Via Vivaldi 43, 81100 Caserta, Italy
| | - Donatella Diana
- Institute of Biostructures and Bioimaging -CNR, Via Mezzocannone 16, 80134 Naples, Italy
| | - Gaetano Malgieri
- Department of Environmental, Biological and Pharmaceutical Sciences and Technology, Via Vivaldi 43, 81100 Caserta, Italy
| | - Ilaria Baglivo
- Department of Environmental, Biological and Pharmaceutical Sciences and Technology, Via Vivaldi 43, 81100 Caserta, Italy
| | - Carla Isernia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technology, Via Vivaldi 43, 81100 Caserta, Italy; Interuniversity Centre for Research on Bioactive Peptides (CIRPEB), University of Naples Federico II, Via Mezzocannone 16, 80134 Naples, Italy
| | - Paolo V Pedone
- Department of Environmental, Biological and Pharmaceutical Sciences and Technology, Via Vivaldi 43, 81100 Caserta, Italy
| | - Roberto Fattorusso
- Department of Environmental, Biological and Pharmaceutical Sciences and Technology, Via Vivaldi 43, 81100 Caserta, Italy; Interuniversity Centre for Research on Bioactive Peptides (CIRPEB), University of Naples Federico II, Via Mezzocannone 16, 80134 Naples, Italy.
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Tetrameric ZBRK1 DNA binding domain has affinity towards cognate DNA in absence of zinc ions. Biochem Biophys Res Commun 2014; 450:283-8. [PMID: 24924633 DOI: 10.1016/j.bbrc.2014.05.104] [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: 05/12/2014] [Accepted: 05/23/2014] [Indexed: 11/22/2022]
Abstract
Zinc finger transcription regulatory proteins play crucial roles in cell-cycle regulation, DNA damage response and tumor genesis. Human ZBRK1 is a zinc-finger transcription repressor protein, which recognizes double helical DNA containing consensus sequences of 5'GGGXXXCAGXXXTTT3'. In the present study, we have purified recombinant DNA binding domain of ZBRK1, and studied binding with zinc ions and DNA, using biophysical techniques. The elution profile of the purified protein suggests that this ZBRK1 forms a homotetramer in solution. Dissociation and pull down assays also suggest that this domain forms a higher order oligomer. The ZBRK1-DNA binding domain acquires higher stability in the presence of zinc ions and DNA. The secondary structure of the ZBRK1-DNA complex is found to be significantly altered from the standard B-DNA conformation.
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26
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Liu D, Geng P, Jiang X, An L, Li W. Structural and functional characterization of the actin-1 gene promoter from the Antheraea pernyi (Lepidoptera: Saturniidae). JOURNAL OF INSECT SCIENCE (ONLINE) 2014; 14:173. [PMID: 25368086 PMCID: PMC5443593 DOI: 10.1093/jisesa/ieu035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 05/06/2013] [Indexed: 06/04/2023]
Abstract
The Chinese oak silkworm, Antheraea pernyi, is an economically important insect of the Saturniidae family. In this study, genome walking was performed to obtain an A. pernyi actin promoter, which can be employed in transgenic or stable cell line expression systems. The putative promoter was analyzed by the online promoter analysis programs at the Berkeley Drosophila Genome Project and the Web Promoter Scan Service, which led to the recognition of several functional elements. With respect to these elements, a series of actin A1 promoter fragments with 5'-deletions were generated that were then used to construct different vectors expressing Green Fluorescent Protein (GFP). The plasmids were transfected into Sf9 cells and GFP expression was determined by observing GFP fluorescence in cells and by measuring GFP mRNA levels with real-time polymerase chain reaction. Sequence comparisons indicated that the sequence cloned from A. pernyi was the actin A1 promoter. The basic function of the promoter was verified by constructing expression vectors and observing GFP expression. In addition, real-time polymerase chain reaction revealed a strong inhibitory element may exist upstream of the TATA box, which downregulated gene expression. The actin A1 promoter is an ideal candidate for use in A. pernyi transgenic systems.
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Affiliation(s)
- Danmei Liu
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, Liaoning 116023, People's Republic of China School of Agriculture, Eastern Liaoning University, Dandong, Liaoning 118000, People's Republic of China
| | - Peng Geng
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, Liaoning 116023, People's Republic of China
| | - Xiran Jiang
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, Liaoning 116023, People's Republic of China
| | - Lijia An
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, Liaoning 116023, People's Republic of China
| | - Wenli Li
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, Liaoning 116023, People's Republic of China
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27
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Steffen PA, Fonseca JP, Ringrose L. Epigenetics meets mathematics: towards a quantitative understanding of chromatin biology. Bioessays 2012; 34:901-13. [PMID: 22911103 DOI: 10.1002/bies.201200076] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
How fast? How strong? How many? So what? Why do numbers matter in biology? Chromatin binding proteins are forever in motion, exchanging rapidly between bound and free pools. How do regulatory systems whose components are in constant flux ensure stability and flexibility? This review explores the application of quantitative and mathematical approaches to mechanisms of epigenetic regulation. We discuss methods for measuring kinetic parameters and protein quantities in living cells, and explore the insights that have been gained by quantifying and modelling dynamics of chromatin binding proteins.
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28
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Berger N, Dubreucq B. Evolution goes GAGA: GAGA binding proteins across kingdoms. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:863-8. [PMID: 22425673 DOI: 10.1016/j.bbagrm.2012.02.022] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 02/17/2012] [Accepted: 02/22/2012] [Indexed: 01/21/2023]
Abstract
Chromatin-associated proteins (CAP) play a crucial role in the regulation of gene expression and development in higher organisms. They are involved in the control of chromatin structure and dynamics. CAP have been extensively studied over the past years and are classified into two major groups: enzymes that modify histone stability and organization by post-translational modification of histone N-Terminal tails; and proteins that use ATP hydrolysis to modify chromatin structure. All of these proteins show a relatively high degree of sequence conservation across the animal and plant kingdoms. The essential Drosophila melanogaster GAGA factor (dGAF) interacts with these two types of CAP to regulate homeobox genes and thus contributes to a wide range of developmental events. Surprisingly, however, it is not conserved in plants. In this review, following an overview of fly GAF functions, we discuss the role of plant BBR/BPC proteins. These appear to functionally converge with dGAF despite a completely divergent amino acid sequence. Some suggestions are given for further investigation into the function of BPC proteins in plants.
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29
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Vogelmann J, Valeri A, Guillou E, Cuvier O, Nollmann M. Roles of chromatin insulator proteins in higher-order chromatin organization and transcription regulation. Nucleus 2011; 2:358-69. [PMID: 21983085 DOI: 10.4161/nucl.2.5.17860] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Eukaryotic chromosomes are condensed into several hierarchical levels of complexity: DNA is wrapped around core histones to form nucleosomes, nucleosomes form a higher-order structure called chromatin, and chromatin is subsequently compartmentalized in part by the combination of multiple specific or unspecific long-range contacts. The conformation of chromatin at these three levels greatly influences DNA metabolism and transcription. One class of chromatin regulatory proteins called insulator factors may organize chromatin both locally, by setting up barriers between heterochromatin and euchromatin, and globally by establishing platforms for long-range interactions. Here, we review recent data revealing a global role of insulator proteins in the regulation of transcription through the formation of clusters of long-range interactions that impact different levels of chromatin organization.
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Affiliation(s)
- Jutta Vogelmann
- Centre de Biochimie Structurale, Centre National de la Recherche Scientifique and Institut National de la Santé et la Recherche Médicale, 29 rue de Navacelles, 34090, Montpellier, France
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30
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Bamps S, Wirtz J, Hope IA. Distinct mechanisms for delimiting expression of four Caenorhabditis elegans transcription factor genes encoding activators or repressors. Mol Genet Genomics 2011; 286:95-107. [PMID: 21655972 DOI: 10.1007/s00438-011-0630-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 05/21/2011] [Indexed: 02/07/2023]
Abstract
Regulatory transcription factors operate in networks, conferring biological robustness that makes dissection of such gene control processes difficult. The nematode Caenorhabditis elegans is a powerful molecular genetic system that allows the close scrutiny needed to understand these processes in an animal, in vivo. Strikingly lower levels of gene expression were observed when a gfp reporter was inserted into C. elegans transcription factor genes, in their broader genomic context, in comparison to when the reporter was fused to just the promoter regions. The lower level of expression is more consistent with endogenous levels of the gene products, based on independent protein and transcript assays. Through successive precise manipulations of the reporter fusion genes, elements essential for the lower level of expression were localised to the protein-coding region. With a closer focus on four transcription factor genes, the expression of both genes encoding transcriptional activators was found to be restricted by a post-transcriptional mechanism while expression of both genes encoding transcriptional repressors was delimited by transcriptional repression. An element through which the transcriptional repression acts for unc-4 was localised to a 30 base-pair region of a protein-encoding exon, with potentially wider implications for how homeobox genes operate. The hypothesis that the distinction in mechanisms delimiting expression of the two types of transcription factor genes, as observed here, may apply more widely is raised. This leads to observations concerning the implications of these different mechanisms on stochastic noise in gene expression and the consequent significance for developmental decisions in general.
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Affiliation(s)
- Sophie Bamps
- Institute of Integrative and Comparative Biology, Faculty of Biological Sciences, The University of Leeds, Leeds LS2 9JT, UK
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31
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Mori H, Ueno-Noto K. A Theoretical Study of the Physicochemical Mechanisms Associated with DNA Recognition Modulation in Artificial Zinc-Finger Proteins. J Phys Chem B 2011; 115:4774-80. [DOI: 10.1021/jp1097348] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Hirotoshi Mori
- Division of Advanced Sciences, Ocha-dai Academic Production, Ochanomizu University, 2-1-1 Ohtsuka, Bunkyo-ku, Tokyo 112-8610, Japan
| | - Kaori Ueno-Noto
- Division of Advanced Sciences, Ocha-dai Academic Production, Ochanomizu University, 2-1-1 Ohtsuka, Bunkyo-ku, Tokyo 112-8610, Japan
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32
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Kenth G, Puzhko S, Goodyer CG. Human growth hormone receptor gene expression is regulated by Gfi-1/1b and GAGA cis-elements. Mol Cell Endocrinol 2011; 335:135-47. [PMID: 21238539 DOI: 10.1016/j.mce.2011.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Revised: 12/20/2010] [Accepted: 01/07/2011] [Indexed: 12/15/2022]
Abstract
Human growth hormone receptor (hGHR) gene regulation is complex: mRNAs are transcribed from multiple variant (V) 5'UTR exons, several ubiquitously while others only in the postnatal hepatocyte. The liver-specific V1 exon promoter contains Gfi-1/1b repressor sites adjacent to a GAGA box, a GH response element (GHRE) in several mammalian genes. GAGA boxes are also present in the ubiquitously expressing V3 exon promoter. Heterologous sites in bovine, ovine and murine GHR genes suggest conserved roles. GAGA factor stimulated V1 and V3 promoters while Gfi-1/1b repressed basal and GAF-stimulated V1 transcription. HGH treatment of HepG2 cells resulted in a new complex forming with V3 GAGA elements, suggesting a functional GHRE. Data suggest liver-specific V1 transcription is regulated by inhibitory Gfi-1/1b and stimulatory GAGA cis-elements and Gfi-1/1b may control the lack of V1 expression in fetal liver, hepatic tumours and non-hepatic tissues. In addition, hGH may regulate hGHR expression through V3 GAGA boxes.
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Affiliation(s)
- Gurvinder Kenth
- Department of Experimental Medicine, McGill University, Montreal, Quebec, Canada
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33
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Aran-Guiu X, Ortiz-Lombardía M, Oliveira E, Bonet Costa C, Odena MA, Bellido D, Bernués J. Acetylation of GAGA Factor Modulates Its Interaction with DNA. Biochemistry 2010; 49:9140-51. [DOI: 10.1021/bi1004427] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Xavier Aran-Guiu
- Institut de Biologia Molecular de Barcelona-CSIC and Institute for Research in Biomedicine Barcelona, Parc Científic de Barcelona, Baldiri Reixac 10-12, 08028 Barcelona, Spain
| | - Miguel Ortiz-Lombardía
- Architecture et Fonction des Macromolécules Biologiques (UMR6098) CNRS, Universités d'Aix-Marseille I & II, Marseille, France
| | - Eliandre Oliveira
- Plataforma de Proteòmica, Parc Científic de Barcelona, Barcelona, Spain
| | - Carles Bonet Costa
- Institut de Biologia Molecular de Barcelona-CSIC and Institute for Research in Biomedicine Barcelona, Parc Científic de Barcelona, Baldiri Reixac 10-12, 08028 Barcelona, Spain
| | | | - David Bellido
- Plataforma de Proteòmica, Parc Científic de Barcelona, Serveis Cientificotècnics, Universitat de Barcelona, Barcelona, Spain
| | - Jordi Bernués
- Institut de Biologia Molecular de Barcelona-CSIC and Institute for Research in Biomedicine Barcelona, Parc Científic de Barcelona, Baldiri Reixac 10-12, 08028 Barcelona, Spain
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34
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Bhatia S, Pawar H, Dasari V, Mishra RK, Chandrashekaran S, Brahmachari V. Chromatin remodeling protein INO80 has a role in regulation of homeotic gene expression in Drosophila. Genes Cells 2010; 15:725-35. [PMID: 20545766 DOI: 10.1111/j.1365-2443.2010.01416.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The homologues of yeast INO80 are identified across phyla from Caenorhabditis elegans to human. In Drosophila it has been shown that dINO80 forms a complex with Pleiohomeotic but does not interact with Hox PRE (polycomb responsive element). As some proteins of the INO80 complex are implicated in homeotic gene regulation, we examined if dINO80 is involved in regulation of homeotic genes. We find that dINO80 null mutants generated by imprecise excision of P-element are late embryonic lethals and show homeotic transformation. We detect misexpression of homeotic genes like Sex-comb reduced, Antennapedia, Ultrabithorax and Abdominal-B in dIno80 mutant embryos by immunostaining which is further substantiated by quantitative PCR. Polycomb phenotype in dIno80-Pc is enhanced in double mutants. Concurrently, the localization of dINO80 to sequences upstream of misexpressed genes in vivo shows that dINO80 is involved in homeotic gene regulation and probably through its interactions with PcG-trxG complexes.
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Affiliation(s)
- Shipra Bhatia
- Dr.B.R.Ambedkar Center for Biomedical Research, University of Delhi, India
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35
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Tkačik G, Walczak AM, Bialek W. Optimizing information flow in small genetic networks. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 80:031920. [PMID: 19905159 PMCID: PMC2928077 DOI: 10.1103/physreve.80.031920] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 07/12/2009] [Indexed: 05/09/2023]
Abstract
In order to survive, reproduce, and (in multicellular organisms) differentiate, cells must control the concentrations of the myriad different proteins that are encoded in the genome. The precision of this control is limited by the inevitable randomness of individual molecular events. Here we explore how cells can maximize their control power in the presence of these physical limits; formally, we solve the theoretical problem of maximizing the information transferred from inputs to outputs when the number of available molecules is held fixed. We start with the simplest version of the problem, in which a single transcription factor protein controls the readout of one or more genes by binding to DNA. We further simplify by assuming that this regulatory network operates in steady state, that the noise is small relative to the available dynamic range, and that the target genes do not interact. Even in this simple limit, we find a surprisingly rich set of optimal solutions. Importantly, for each locally optimal regulatory network, all parameters are determined once the physical constraints on the number of available molecules are specified. Although we are solving an oversimplified version of the problem facing real cells, we see parallels between the structure of these optimal solutions and the behavior of actual genetic regulatory networks. Subsequent papers will discuss more complete versions of the problem.
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Affiliation(s)
- Gašper Tkačik
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6396, USA
| | - Aleksandra M. Walczak
- Joseph Henry Laboratories of Physics, Lewis-Sigler Institute for Integrative Genomics, and Princeton Center for Theoretical Science, Princeton University, Princeton, New Jersey 08544, USA
| | - William Bialek
- Joseph Henry Laboratories of Physics, Lewis-Sigler Institute for Integrative Genomics, and Princeton Center for Theoretical Science, Princeton University, Princeton, New Jersey 08544, USA
- Center for Studies in Physics and Biology, The Rockefeller University, New York, New York 10065, USA
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36
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Onn I, Guacci V, Koshland DE. The zinc finger of Eco1 enhances its acetyltransferase activity during sister chromatid cohesion. Nucleic Acids Res 2009; 37:6126-34. [PMID: 19692582 PMCID: PMC2764436 DOI: 10.1093/nar/gkp656] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
| | | | - Douglas E. Koshland
- *To whom correspondence should be addressed. Tel: +1 (410) 246 3016; Fax: +1 (410) 243 6311;
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37
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Baglivo I, Russo L, Esposito S, Malgieri G, Renda M, Salluzzo A, Di Blasio B, Isernia C, Fattorusso R, Pedone PV. The structural role of the zinc ion can be dispensable in prokaryotic zinc-finger domains. Proc Natl Acad Sci U S A 2009; 106:6933-8. [PMID: 19369210 PMCID: PMC2678482 DOI: 10.1073/pnas.0810003106] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Indexed: 11/18/2022] Open
Abstract
The recent characterization of the prokaryotic Cys(2)His(2) zinc-finger domain, identified in Ros protein from Agrobacterium tumefaciens, has demonstrated that, although possessing a similar zinc coordination sphere, this domain is structurally very different from its eukaryotic counterpart. A search in the databases has identified approximately 300 homologues with a high sequence identity to the Ros protein, including the amino acids that form the extensive hydrophobic core in Ros. Surprisingly, the Cys(2)His(2) zinc coordination sphere is generally poorly conserved in the Ros homologues, raising the question of whether the zinc ion is always preserved in these proteins. Here, we present a functional and structural study of a point mutant of Ros protein, Ros(56-142)C82D, in which the second coordinating cysteine is replaced by an aspartate, 5 previously-uncharacterized representative Ros homologues from Mesorhizobium loti, and 2 mutants of the homologues. Our results indicate that the prokaryotic zinc-finger domain, which in Ros protein tetrahedrally coordinates Zn(II) through the typical Cys(2)His(2) coordination, in Ros homologues can either exploit a CysAspHis(2) coordination sphere, previously never described in DNA binding zinc finger domains to our knowledge, or lose the metal, while still preserving the DNA-binding activity. We demonstrate that this class of prokaryotic zinc-finger domains is structurally very adaptable, and surprisingly single mutations can transform a zinc-binding domain into a nonzinc-binding domain and vice versa, without affecting the DNA-binding ability. In light of our findings an evolutionary link between the prokaryotic and eukaryotic zinc-finger domains, based on bacteria-to-eukaryota horizontal gene transfer, is discussed.
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Affiliation(s)
- Ilaria Baglivo
- Dipartimento di Scienze Ambientali, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100 Caserta, Italy; and
| | - Luigi Russo
- Dipartimento di Scienze Ambientali, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100 Caserta, Italy; and
| | - Sabrina Esposito
- Dipartimento di Scienze Ambientali, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100 Caserta, Italy; and
| | - Gaetano Malgieri
- Dipartimento di Scienze Ambientali, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100 Caserta, Italy; and
| | - Mario Renda
- Dipartimento di Scienze Ambientali, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100 Caserta, Italy; and
| | - Antonio Salluzzo
- Department of Environment, Global Change, and Sustainable Development, Portici Research Center, Italian National Agency for New Technologies, Energy, and the Environment, Via Vecchio Macello, 80055 Portici, Italy
| | - Benedetto Di Blasio
- Dipartimento di Scienze Ambientali, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100 Caserta, Italy; and
| | - Carla Isernia
- Dipartimento di Scienze Ambientali, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100 Caserta, Italy; and
| | - Roberto Fattorusso
- Dipartimento di Scienze Ambientali, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100 Caserta, Italy; and
| | - Paolo V. Pedone
- Dipartimento di Scienze Ambientali, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100 Caserta, Italy; and
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38
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Expression profiling during ocular development identifies 2 Nlz genes with a critical role in optic fissure closure. Proc Natl Acad Sci U S A 2009; 106:1462-7. [PMID: 19171890 DOI: 10.1073/pnas.0812017106] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The gene networks underlying closure of the optic fissure during vertebrate eye development are poorly understood. Here, we profile global gene expression during optic fissure closure using laser capture microdissected (LCM) tissue from the margins of the fissure. From these data, we identify a unique role for the C(2)H(2) zinc finger proteins Nlz1 and Nlz2 in normal fissure closure. Gene knockdown of nlz1 and/or nlz2 in zebrafish leads to a failure of the optic fissure to close, a phenotype which closely resembles that seen in human uveal coloboma. We also identify misregulation of pax2 in the developing eye of morphant fish, suggesting that Nlz1 and Nlz2 act upstream of the Pax2 pathway in directing proper closure of the optic fissure.
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39
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Chen YC, Lin SI, Chen YK, Chiang CS, Liaw GJ. The Torso signaling pathway modulates a dual transcriptional switch to regulate tailless expression. Nucleic Acids Res 2009; 37:1061-72. [PMID: 19129218 PMCID: PMC2651784 DOI: 10.1093/nar/gkn1036] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The Torso (Tor) signaling pathway activates tailless (tll) expression by relieving tll repression. None of the repressors identified so far, such as Capicuo, Groucho and Tramtrack69 (Ttk69), bind to the tor response element (tor-RE) or fully elucidate tll repression. In this study, an expanded tll expression pattern was shown in embryos with reduced heat shock factor (hsf) and Trithorax-like (Trl) activities. The GAGA factor, GAF encoded by Trl, bound weakly to the tor-RE, and this binding was enhanced by both Hsf and Ttk69. A similar extent of expansion of tll expression was observed in embryos with simultaneous knockdown of hsf, Trl and ttk69 activities, and in embryos with constitutively active Tor. Hsf is a substrate of mitogen-activated protein kinase and S378 is the major phosphorylation site. Phosphorylation converts Hsf from a repressor to an activator that works with GAF to activate tll expression. In conclusion, the GAF/Hsf/Ttk69 complex binding to the tor-RE remodels local chromatin structure to repress tll expression and the Tor signaling pathway activate tll expression by modulating a dual transcriptional switch.
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Affiliation(s)
- Yu-Chien Chen
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, 112 Taiwan, ROC
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40
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Dhanasekaran M, Negi S, Imanishi M, Suzuki M, Sugiura Y. Effects of Bulkiness and Hydrophobicity of an Aliphatic Amino Acid in the Recognition Helix of the GAGA Zinc Finger on the Stability of the Hydrophobic Core and DNA Binding Affinity. Biochemistry 2008; 47:11717-24. [DOI: 10.1021/bi801306d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Muthu Dhanasekaran
- Faculty of Pharmaceutical Sciences, Doshisha Women’s University, Koudo, Kyotanabe-Shi 610-0395, Japan, and Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan
| | - Shigeru Negi
- Faculty of Pharmaceutical Sciences, Doshisha Women’s University, Koudo, Kyotanabe-Shi 610-0395, Japan, and Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan
| | - Miki Imanishi
- Faculty of Pharmaceutical Sciences, Doshisha Women’s University, Koudo, Kyotanabe-Shi 610-0395, Japan, and Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan
| | - Michiko Suzuki
- Faculty of Pharmaceutical Sciences, Doshisha Women’s University, Koudo, Kyotanabe-Shi 610-0395, Japan, and Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan
| | - Yukio Sugiura
- Faculty of Pharmaceutical Sciences, Doshisha Women’s University, Koudo, Kyotanabe-Shi 610-0395, Japan, and Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan
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41
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Abstract
Gene expression levels fluctuate even under constant external conditions. Much emphasis has usually been placed on the components of this noise that are due to randomness in transcription and translation. Here we focus on the role of noise associated with the inputs to transcriptional regulation; in particular, we analyze the effects of random arrival times and binding of transcription factors to their target sites along the genome. This contribution to the total noise sets a fundamental physical limit to the reliability of genetic control, and has clear signatures, but we show that these are easily obscured by experimental limitations and even by conventional methods for plotting the variance vs. mean expression level. We argue that simple, universal models of noise dominated by transcription and translation are inconsistent with the embedding of gene expression in a network of regulatory interactions. Analysis of recent experiments on transcriptional control in the early Drosophila embryo shows that these results are quantitatively consistent with the predicted signatures of input noise, and we discuss the experiments needed to test the importance of input noise more generally.
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42
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Bialek W, Setayeshgar S. Cooperativity, sensitivity, and noise in biochemical signaling. PHYSICAL REVIEW LETTERS 2008; 100:258101. [PMID: 18643705 DOI: 10.1103/physrevlett.100.258101] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2007] [Indexed: 05/26/2023]
Abstract
Cooperative interactions in the binding of multiple signaling molecules is a common mechanism for enhancing the sensitivity of biological signaling systems. It is widely assumed this increase in sensitivity of the mean response implies the ability to detect smaller signals. Extending the classic work of Berg and Purcell [Biophys. J. 20, 193 (1977)] on the physical limits of chemoreception, we show that the random arrival of diffusing signaling molecules at receptor sites constitutes a noise source that is not reduced by cooperativity. Cooperativity makes reaching this limit easier, but cannot reduce the limit itself.
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Affiliation(s)
- William Bialek
- Joseph Henry Laboratories of Physics, Lewis-Sigler Institute for Integrative Genomics, and Princeton Center for Theoretical Physics, Princeton University, Princeton, New Jersey 08544, USA
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43
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Negi S, Imanishi M, Matsumoto M, Sugiura Y. New redesigned zinc-finger proteins: design strategy and its application. Chemistry 2008; 14:3236-49. [PMID: 18236477 DOI: 10.1002/chem.200701320] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The design of DNA-binding proteins for the specific control of the gene expression is one of the big challenges for several research laboratories in the post-genomic era. An artificial transcription factor with the desired DNA binding specificity could work as a powerful tool and drug to regulate the target gene. The zinc-finger proteins, which typically contain many fingers linked in a tandem fashion, are some of the most intensively studied DNA-binding proteins. In particular, the Cys(2)His(2)-type zinc finger is one of the most common DNA-binding motifs in eukaryotes. A simple mode of DNA recognition by the Cys(2)His(2)-type zinc-finger domain provides an ideal framework for designing proteins with new functions. Our laboratory has utilized several design strategies to create new zinc-finger peptides/proteins by redesigning the Cys(2)His(2)-type zinc-finger motif. This review focuses on the aspects of design strategies, mainly from our recent results, for the creation of artificial zinc-finger proteins, and discusses the possible application of zinc-finger technology for gene regulation and gene therapy.
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Affiliation(s)
- Shigeru Negi
- Faculty of Pharmaceutical Sciences, Doshisha Women's University, Koudo, Kyotanabe-Shi, Japan.
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44
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Vázquez O, Vázquez ME, Blanco JB, Castedo L, Mascareñas JL. Specific DNA recognition by a synthetic, monomeric Cys2His2 zinc-finger peptide conjugated to a minor-groove binder. Angew Chem Int Ed Engl 2007; 46:6886-90. [PMID: 17674388 DOI: 10.1002/anie.200702345] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Olalla Vázquez
- Department de Química Orgánica y Unidad Asociada al CSIC, Universidade de Santiago de Compostela, Facultade de Química, 15782 Santiago de Compostela, Spain
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45
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The prokaryotic Cys2His2 zinc-finger adopts a novel fold as revealed by the NMR structure of Agrobacterium tumefaciens Ros DNA-binding domain. Proc Natl Acad Sci U S A 2007; 104:17341-6. [PMID: 17956987 DOI: 10.1073/pnas.0706659104] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The first putative prokaryotic Cys(2)His(2) zinc-finger domain has been identified in the transcriptional regulator Ros from Agrobacterium tumefaciens, indicating that the Cys(2)His(2) zinc-finger domain, originally thought to be confined to the eukaryotic kingdom, could be widespread throughout the living kingdom from eukaryotic, both animal and plant, to prokaryotic. In this article we report the NMR solution structure of Ros DNA-binding domain (Ros87), providing 79 structural characterization of a prokaryotic Cys(2)His(2) zinc-finger domain. The NMR structure of Ros87 shows that the putative prokaryotic Cys(2)His(2) zinc-finger sequence is indeed part of a significantly larger zinc-binding globular domain that possesses a novel protein fold very different from the classical fold reported for the eukaryotic classical zinc-finger. The Ros87 globular domain consists of 58 aa (residues 9-66), is arranged in a betabetabetaalphaalpha topology, and is stabilized by an extensive 15-residue hydrophobic core. A backbone dynamics study of Ros87, based on (15)N R(1), (15)N R(2), and heteronuclear (15)N-{(1)H}-NOE measurements, has further confirmed that the globular domain is uniformly rigid and flanked by two flexible tails. Mapping of the amino acids necessary for the DNA binding onto Ros87 structure reveals the protein surface involved in the DNA recognition mechanism of this new zinc-binding protein domain.
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46
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Bernués J, Piñeyro D, Kosoy A. General, negative feedback mechanism for regulation of Trithorax-like gene expression in vivo: new roles for GAGA factor in flies. Nucleic Acids Res 2007; 35:7150-9. [PMID: 17947335 PMCID: PMC2175371 DOI: 10.1093/nar/gkm590] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Expression of every gene is first regulated at the transcriptional level. While some genes show acute and discrete periods of expression others show a rather steady expression level throughout development. An example of the latter is Trithorax-like (Trl) a member of the Trithorax group that encodes GAGA factor in Drosophila. Among other functions, GAGA factor has been described to stimulate transcription of several genes, including some homeotic genes. Here we show that GAGA factor is continuously down-regulating the expression of its own promoter using a negative feedback mechanism in vivo. Like its expression, repression by GAGA factor is ubiquitous, prevents its accumulation, and takes place throughout development. Experimental alteration of GAGA factor dosage results in several unexpected phenotypes, not related to alteration of homeotic gene expression, but rather to functions that take place later during development and affect different morphogenetic processes. The results suggest that GAGA factor is essential during development, even after homeotic gene expression is established, and indicate the existence of an upper limit for GAGA factor dosage that should not be exceeded.
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Affiliation(s)
- Jordi Bernués
- Institut de Biologia Molecular de Barcelona-CSIC, Parc Científic de Barcelona, Josep Samitier, 1-5, 08028 Barcelona, Spain.
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47
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Vázquez O, Vázquez M, Blanco J, Castedo L, Mascareñas J. Specific DNA Recognition by a Synthetic, Monomeric Cys2His2 Zinc-Finger Peptide Conjugated to a Minor-Groove Binder. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200702345] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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48
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Gregor T, Tank DW, Wieschaus EF, Bialek W. Probing the limits to positional information. Cell 2007; 130:153-64. [PMID: 17632062 PMCID: PMC2253670 DOI: 10.1016/j.cell.2007.05.025] [Citation(s) in RCA: 488] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2006] [Revised: 02/15/2007] [Accepted: 05/03/2007] [Indexed: 11/22/2022]
Abstract
The reproducibility and precision of biological patterning is limited by the accuracy with which concentration profiles of morphogen molecules can be established and read out by their targets. We consider four measures of precision for the Bicoid morphogen in the Drosophila embryo: the concentration differences that distinguish neighboring cells, the limits set by the random arrival of Bicoid molecules at their targets (which depends on absolute concentration), the noise in readout of Bicoid by the activation of Hunchback, and the reproducibility of Bicoid concentration at corresponding positions in multiple embryos. We show, through a combination of different experiments, that all of these quantities are approximately 10%. This agreement among different measures of accuracy indicates that the embryo is not faced with noisy input signals and readout mechanisms; rather, the system exerts precise control over absolute concentrations and responds reliably to small concentration differences, approaching the limits set by basic physical principles.
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Affiliation(s)
- Thomas Gregor
- Joseph Henry Laboratories of Physics, Princeton University, Princeton, NJ 08544, USA.
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49
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Adkins NL, Hagerman TA, Georgel P. GAGA protein: a multi-faceted transcription factor. Biochem Cell Biol 2007; 84:559-67. [PMID: 16936828 DOI: 10.1139/o06-062] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The transition from transcription activation to repression is regulated at multiple levels by the DNA sequence and DNA modification to its compaction through chromatin packaging. The GAGA factor (GAF) is one of a few transcription factors that can regulate gene expression at multiple levels. It displays both activator/antirepressor and repressor activity, depending on its target genomic location. The GAF-mediated modulation of expression appears to be intimately linked with modifications of the chromatin structure. The GAF can associate with highly compacted heterochromatin, contributing to gene repression, or participate in nucleosome remodeling to activate specific genes. In this review, we are attempting to elucidate the contribution(s) of the various domains of the GAF to the recruitment of its functional partners, leading to seemingly opposite functions. We surveyed the current scientific literature for evidence of GAF involvement in regulatory events associated with changes of chromatin composition or conformation.
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Affiliation(s)
- Nicholas L Adkins
- Department of Biological Sciences, Marshall University, 1 John Marshall Drive, Huntington, WV, 25755, USA
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50
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Kim S, Choi K, Park C, Hwang HJ, Lee I. SUPPRESSOR OF FRIGIDA4, encoding a C2H2-Type zinc finger protein, represses flowering by transcriptional activation of Arabidopsis FLOWERING LOCUS C. THE PLANT CELL 2006; 18:2985-98. [PMID: 17138694 PMCID: PMC1693938 DOI: 10.1105/tpc.106.045179] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
FLOWERING LOCUS C (FLC), a strong floral repressor, is one of the central regulators of flowering in Arabidopsis thaliana. The expression of FLC is increased by FRIGIDA (FRI) but decreased by vernalization, a long period of cold exposure that accelerates flowering. Although many aspects of FLC regulation have been reported, it is not known how FLC is transcriptionally activated by FRI at the molecular level. We isolated suppressor of FRIGIDA4 (suf4), a mutant that flowers early as a result of low FLC expression. SUF4 encodes a nuclear-localized protein with two C2H2-type zinc finger motifs and a Pro-rich domain. SUF4 protein interacts with FRI and FRIGIDA-LIKE1 (FRL1), two genes for which single mutations have the same phenotype as suf4. SUF4 also bound to the promoter of FLC in a chromatin immunoprecipitation assay, suggesting that SUF4 acts as a transcriptional activator of FLC after forming a complex with FRI and FRL1. In addition, suf4 suppresses luminidependens (ld), a late-flowering mutation that causes an increase of FLC, and SUF4 protein directly interacts with LD. Thus, we propose that LD binds to SUF4 to suppress its activity in the absence of FRI.
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Affiliation(s)
- Sanghee Kim
- National Research Laboratory of Plant Developmental Genetics, Department of Biological Sciences, Seoul National University, Seoul 151-742, Korea
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