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Yu X, Buck MJ. Pioneer factors and their in vitro identification methods. Mol Genet Genomics 2020; 295:825-835. [PMID: 32296927 DOI: 10.1007/s00438-020-01675-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 04/02/2020] [Indexed: 11/27/2022]
Abstract
Pioneer transcription factors are a special group of transcription factors that can interact with nucleosomal DNA and initiate regulatory events. Their binding to regulatory regions is the first event in gene activation and can occur in silent or heterochromatin regions. Several research groups have endeavored to define pioneer factors and study their binding characteristics using various techniques. In this review, we describe the in vitro methods used to define and characterize pioneer factors, paying particular attention to differences in methodologies and how these differences can affect results.
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Affiliation(s)
- Xinyang Yu
- Zhuhai Precision Medical Center, Zhuhai People's Hospital (Zhuhai Hospital Affiliated With Jinan University), Zhuhai, 519000, Guangdong, P.R. China.
| | - Michael J Buck
- Department of Biochemistry, New York State Center of Excellence in Bioinformatics and Life Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA.
- Department of Biomedical Informatics, State University of New York at Buffalo, Buffalo, NY, 14203, USA.
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2
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Lorzadeh A, Lopez Gutierrez R, Jackson L, Moksa M, Hirst M. Generation of Native Chromatin Immunoprecipitation Sequencing Libraries for Nucleosome Density Analysis. J Vis Exp 2017. [PMID: 29286469 PMCID: PMC5755553 DOI: 10.3791/56085] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
We present a modified native chromatin immunoprecipitation sequencing (ChIP-seq) experimental protocol compatible with a Gaussian mixture distribution based analysis methodology (nucleosome density ChIP-seq; ndChIP-seq) that enables the generation of combined measurements of micrococcal nuclease (MNase) accessibility with histone modification genome-wide. Nucleosome position and local density, and the posttranslational modification of their histone subunits, act in concert to regulate local transcription states. Combinatorial measurements of nucleosome accessibility with histone modification generated by ndChIP-seq allows for the simultaneous interrogation of these features. The ndChIP-seq methodology is applicable to small numbers of primary cells inaccessible to cross-linking based ChIP-seq protocols. Taken together, ndChIP-seq enables the measurement of histone modification in combination with local nucleosome density to obtain new insights into shared mechanisms that regulate RNA transcription within rare primary cell populations.
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Affiliation(s)
- Alireza Lorzadeh
- Department of Microbiology and Immunology, Michael Smith Laboratories Centre for High-Throughput Biology, University of British Columbia
| | - Rodrigo Lopez Gutierrez
- Department of Microbiology and Immunology, Michael Smith Laboratories Centre for High-Throughput Biology, University of British Columbia
| | - Linda Jackson
- Department of Microbiology and Immunology, Michael Smith Laboratories Centre for High-Throughput Biology, University of British Columbia
| | - Michelle Moksa
- Department of Microbiology and Immunology, Michael Smith Laboratories Centre for High-Throughput Biology, University of British Columbia
| | - Martin Hirst
- Department of Microbiology and Immunology, Michael Smith Laboratories Centre for High-Throughput Biology, University of British Columbia; Canada's Michael Smith Genome Science Center, BC Cancer Agency;
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3
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Lorzadeh A, Bilenky M, Hammond C, Knapp DJHF, Li L, Miller PH, Carles A, Heravi-Moussavi A, Gakkhar S, Moksa M, Eaves CJ, Hirst M. Nucleosome Density ChIP-Seq Identifies Distinct Chromatin Modification Signatures Associated with MNase Accessibility. Cell Rep 2017; 17:2112-2124. [PMID: 27851972 DOI: 10.1016/j.celrep.2016.10.055] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 07/05/2016] [Accepted: 09/12/2016] [Indexed: 12/22/2022] Open
Abstract
Nucleosome position, density, and post-translational modification are widely accepted components of mechanisms regulating DNA transcription but still incompletely understood. We present a modified native ChIP-seq method combined with an analytical framework that allows MNase accessibility to be integrated with histone modification profiles. Application of this methodology to the primitive (CD34+) subset of normal human cord blood cells enabled genomic regions enriched in one versus two nucleosomes marked by histone 3 lysine 4 trimethylation (H3K4me3) and/or histone 3 lysine 27 trimethylation (H3K27me3) to be associated with their transcriptional and DNA methylation states. From this analysis, we defined four classes of promoter-specific profiles and demonstrated that a majority of bivalent marked promoters are heterogeneously marked at a single-cell level in this primitive cell type. Interestingly, extension of this approach to human embryonic stem cells revealed an altered relationship between chromatin modification state and nucleosome content at promoters, suggesting developmental stage-specific organization of histone methylation states.
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Affiliation(s)
- Alireza Lorzadeh
- Department of Microbiology and Immunology, Michael Smith Laboratories Centre for High-Throughput Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Misha Bilenky
- Canada's Michael Smith Genome Science Center, BC Cancer Agency Vancouver, BC V5Z 4S6, Canada
| | - Colin Hammond
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - David J H F Knapp
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - Luolan Li
- Department of Microbiology and Immunology, Michael Smith Laboratories Centre for High-Throughput Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Paul H Miller
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - Annaick Carles
- Department of Microbiology and Immunology, Michael Smith Laboratories Centre for High-Throughput Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Alireza Heravi-Moussavi
- Canada's Michael Smith Genome Science Center, BC Cancer Agency Vancouver, BC V5Z 4S6, Canada
| | - Sitanshu Gakkhar
- Canada's Michael Smith Genome Science Center, BC Cancer Agency Vancouver, BC V5Z 4S6, Canada
| | - Michelle Moksa
- Department of Microbiology and Immunology, Michael Smith Laboratories Centre for High-Throughput Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Connie J Eaves
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, BC V6H 3N1, Canada
| | - Martin Hirst
- Department of Microbiology and Immunology, Michael Smith Laboratories Centre for High-Throughput Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Canada's Michael Smith Genome Science Center, BC Cancer Agency Vancouver, BC V5Z 4S6, Canada.
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4
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W-enriched satellite sequence in the Indian meal moth, Plodia interpunctella (Lepidoptera, Pyralidae). Chromosome Res 2017; 25:241-252. [PMID: 28500471 DOI: 10.1007/s10577-017-9558-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 04/24/2017] [Accepted: 04/27/2017] [Indexed: 10/19/2022]
Abstract
The W chromosome of most lepidopteran species represents the largest heterochromatin entity in the female genome. Although satellite DNA is a typical component of constitutive heterochromatin, there are only a few known satellite DNAs (satDNAs) located on the W chromosome in moths and butterflies. In this study, we isolated and characterized new satDNA (PiSAT1) from microdissected W chromosomes of the Indian meal moth, Plodia interpunctella. Even though the PiSAT1 is mainly localized near the female-specific segment of the W chromosome, short arrays of this satDNA also occur on autosomes and/or the Z chromosome. Probably due to the predominant location in the non-recombining part of the genome, PiSAT1 exhibits a relatively large nucleotide variability in its monomers. However, at least a part of all predicted functional motifs is located in conserved regions. Moreover, we detected polyadenylated transcripts of PiSAT1 in all developmental stages and in both sexes (female and male larvae, pupae and adults). Our results suggest a potential structural and functional role of PiSAT1 in the P. interpunctella genome, which is consistent with accumulating evidence for the important role of satDNAs in eukaryotic genomes.
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5
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Krinner S, Heitzer AP, Diermeier SD, Obermeier I, Längst G, Wagner R. CpG domains downstream of TSSs promote high levels of gene expression. Nucleic Acids Res 2014; 42:3551-64. [PMID: 24413563 PMCID: PMC3973331 DOI: 10.1093/nar/gkt1358] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
CpG dinucleotides are known to play a crucial role in regulatory domains, affecting gene expression in their natural context. Here, we demonstrate that intragenic CpG frequency and distribution impacts transgene and genomic gene expression levels in mammalian cells. As shown for the Macrophage Inflammatory Protein 1α, de novo RNA synthesis correlates with the number of CpG dinucleotides, whereas RNA splicing, stability, nuclear export and translation are not affected by the sequence modification. Differences in chromatin accessibility in vivo and altered nucleosome positioning in vitro suggest that increased CpG levels destabilize the chromatin structure. Moreover, enriched CpG levels correlate with increased RNA polymerase II elongation rates in vivo. Interestingly, elevated CpG levels particularly at the 5′ end of the gene promote efficient transcription. We show that this is a genome-wide feature of highly expressed genes, by identifying a domain of ∼700 bp with high CpG content downstream of the transcription start site, correlating with high levels of transcription. We suggest that these 5′ CpG domains are required to distort the chromatin structure and to increase gene activity.
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Affiliation(s)
- Simone Krinner
- Department of Molecular Microbiology & Gene Therapy, Institute of Medical Microbiology and Hygiene, University Hospital of Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany and Department of Biochemistry III, Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
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Abstract
Precise positioning of nucleosomes along DNA is important for a variety of gene regulatory processes. Among the factors directing nucleosome positioning, the DNA sequence is highly important. Two main classes of nucleosome positioning sequence (NPS) patterns have previously been described. In the first class, AA, TT, and other WW dinucleotides (where W is A or T) tend to occur together (in-phase) in the major groove of DNA closest to the histone octamer surface, while SS dinucleotides (where S is G or C) are predominantly positioned in the major groove facing outward. In the second class, AA and TT are structurally separated (AA backbone near the histone octamer, and TT backbone further away), but grouped with other RR (where R is purine A or G) and YY (where Y is pyrimidine C or T) dinucleotides. As a result, the RR/YY pattern includes counter-phase AA/TT distributions. We describe here anti-NPS patterns, which are inverse to the conventional NPS patterns: WW runs inverse to SS, and RR inverse to YY. Evidence for the biological relevance of anti-NPS patterns is presented.
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Ganapathi M, Palumbo MJ, Ansari SA, He Q, Tsui K, Nislow C, Morse RH. Extensive role of the general regulatory factors, Abf1 and Rap1, in determining genome-wide chromatin structure in budding yeast. Nucleic Acids Res 2010; 39:2032-44. [PMID: 21081559 PMCID: PMC3064788 DOI: 10.1093/nar/gkq1161] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The packaging of eukaryotic DNA into chromatin has profound consequences for gene regulation, as well as for other DNA transactions such as recombination, replication and repair. Understanding how this packaging is determined is consequently a pressing problem in molecular genetics. DNA sequence, chromatin remodelers and transcription factors affect chromatin structure, but the scope of these influences on genome-wide nucleosome occupancy patterns remains uncertain. Here, we use high resolution tiling arrays to examine the contributions of two general regulatory factors, Abf1 and Rap1, to nucleosome occupancy in Saccharomyces cerevisiae. These factors have each been shown to bind to a few hundred promoters, but we find here that thousands of loci show localized regions of altered nucleosome occupancy within 1 h of loss of Abf1 or Rap1 binding, and that altered chromatin structure can occur via binding sites having a wide range of affinities. These results indicate that DNA-binding transcription factors affect chromatin structure, and probably dynamics, throughout the genome to a much greater extent than previously appreciated.
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Affiliation(s)
- Mythily Ganapathi
- Laboratory of Molecular Genetics, New York State Department of Health, Wadsworth Center, Albany, NY 12201-0509, USA
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8
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Abstract
Embryonic stem (ES) cells are pluripotent cells that can self renew or be induced to differentiate into multiple cell lineages, and thus have the potential to be utilized in regenerative medicine. Key pluripotency specific factors (Oct 4/Sox2/Nanog/Klf4) maintain the pluripotent state by activating expression of pluripotency specific genes and by inhibiting the expression of developmental regulators. Pluripotent ES cells are distinguished from differentiated cells by a specialized chromatin state that is required to epigenetically regulate the ES cell phenotype. Recent studies show that in addition to pluripotency specific factors, chromatin remodeling enzymes play an important role in regulating ES cell chromatin and the capacity to self-renew and to differentiate. Here we review recent studies that delineate the role of ATP dependent chromatin remodeling enzymes in regulating ES cell chromatin structure.
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Abstract
The primary role of the nucleus as an information storage, retrieval, and replication site requires the physical organization and compaction of meters of DNA. Although it has been clear for many years that nucleosomes constitute the first level of chromatin compaction, this contributes a relatively small fraction of the condensation needed to fit the typical genome into an interphase nucleus or set of metaphase chromosomes, indicating that there are additional "higher order" levels of chromatin condensation. Identifying these levels, their interrelationships, and the principles that govern their occurrence has been a challenging and much discussed problem. In this article, we focus on recent experimental advances and the emerging evidence indicating that structural plasticity and chromatin dynamics play dominant roles in genome organization. We also discuss novel approaches likely to yield important insights in the near future, and suggest research areas that merit further study.
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10
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Bauer AP, Leikam D, Krinner S, Notka F, Ludwig C, Längst G, Wagner R. The impact of intragenic CpG content on gene expression. Nucleic Acids Res 2010; 38:3891-908. [PMID: 20203083 PMCID: PMC2896515 DOI: 10.1093/nar/gkq115] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The development of vaccine components or recombinant therapeutics critically depends on sustained expression of the corresponding transgene. This study aimed to determine the contribution of intragenic CpG content to expression efficiency in transiently and stably transfected mammalian cells. Based upon a humanized version of green fluorescent protein (GFP) containing 60 CpGs within its coding sequence, a CpG-depleted variant of the GFP reporter was established by carefully modulating the codon usage. Interestingly, GFP reporter activity and detectable protein amounts in stably transfected CHO and 293 cells were significantly decreased upon CpG depletion and independent from promoter usage (CMV, EF1α). The reduction in protein expression associated with CpG depletion was likewise observed for other unrelated reporter genes and was clearly reflected by a decline in mRNA copy numbers rather than translational efficiency. Moreover, decreased mRNA levels were neither due to nuclear export restrictions nor alternative splicing or mRNA instability. Rather, the intragenic CpG content influenced de novo transcriptional activity thus implying a common transcription-based mechanism of gene regulation via CpGs. Increased high CpG transcription correlated with changed nucleosomal positions in vitro albeit histone density at the two genes did not change in vivo as monitored by ChIP.
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Affiliation(s)
- Asli Petra Bauer
- Institute of Medical Microbiology and Hygiene, Molecular Microbiology & Gene Therapy Unit, University of Regensburg, Regensburg, Germany
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11
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Vinayachandran V, Pusarla RH, Bhargava P. Multiple sequence-directed possibilities provide a pool of nucleosome position choices in different states of activity of a gene. Epigenetics Chromatin 2009; 2:4. [PMID: 19291282 PMCID: PMC2667510 DOI: 10.1186/1756-8935-2-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Accepted: 03/16/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Genome-wide mappings of nucleosome occupancy in different species have shown presence of well-positioned nucleosomes. While the DNA sequences may help decide their locations, the observed positions in vivo are end-results of chromatin remodeling, the state of gene activity and binding of the sequence-specific factors to the DNA, all of which influence nucleosome positions. Thus, the observed nucleosome locations in vivo do not reflect the true contribution of DNA sequence to the mapped position. Moreover, the naturally occurring nucleosome-positioning sequences are known to guide multiple translational positionings. RESULTS We show that yeast SNR6, a gene transcribed by RNA polymerase III, constitutes nucleosome-positioning sequence. In the absence of a chromatin remodeler or any factor binding, the gene sequence confers a unique rotational phase to nucleosomes in the gene region, and directs assembly of several translationally positioned nucleosomes on approximately 1.2 kb DNA from the gene locus, including the short approximately 250 bp gene region. Mapping of all these gene sequence-directed nucleosome positions revealed that the array of nucleosomes in the gene upstream region occupy the same positions as those observed in vivo but the nucleosomes on the gene region can be arranged in three distinct registers. Two of these arrangements differ from each other in the position of only one nucleosome, and match with the nucleosome positions on the gene in repressed and active states in vivo, where the gene-specific factor is known to occupy the gene in both the states. The two positions are interchanged by an ATP-dependent chromatin remodeler in vivo. The third register represents the positions which block the access of the factor to the gene promoter elements. CONCLUSION On a gene locus, multiple nucleosome positions are directed by a gene sequence to provide a pool of possibilities, out of which the preferred ones are selected by the chromatin remodeler and transcription factor of the gene under different states of activity of the gene.
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Affiliation(s)
- Vinesh Vinayachandran
- Centre for Cellular and Molecular Biology, (Council of Scientific and Industrial Research), Uppal Road, Hyderabad-500007, India.
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12
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Yu S, Smirnova JB, Friedberg EC, Stillman B, Akiyama M, Owen-Hughes T, Waters R, Reed SH. ABF1-binding sites promote efficient global genome nucleotide excision repair. J Biol Chem 2008; 284:966-73. [PMID: 18996839 DOI: 10.1074/jbc.m806830200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Global genome nucleotide excision repair (GG-NER) removes DNA damage from nontranscribing DNA. In Saccharomyces cerevisiae, the RAD7 and RAD16 genes are specifically required for GG-NER. We have reported that autonomously replicating sequence-binding factor 1 (ABF1) protein forms a stable complex with Rad7 and Rad16 proteins. ABF1 functions in transcription, replication, gene silencing, and NER in yeast. Here we show that binding of ABF1 to its DNA recognition sequence found at multiple genomic locations promotes efficient GG-NER in yeast. Mutation of the I silencer ABF1-binding site at the HMLalpha locus caused loss of ABF1 binding, which resulted in a domain of reduced GG-NER efficiency on one side of the ABF1-binding site. During GG-NER, nucleosome positioning at this site was not altered, and this correlated with an inability of the GG-NER complex to reposition nucleosomes in vitro.We discuss how the GG-NER complex might facilitate GG-NER while preventing unregulated gene transcription during this process.
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Affiliation(s)
- Shirong Yu
- Department of Pathology, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom
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13
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Affiliation(s)
- Brian McStay
- Biomedical Research Center, Ninewells Hospital, University of Dundee, Dundee DD1 9SY, United Kingdom;
| | - Ingrid Grummt
- Molecular Biology of the Cell II, German Cancer Research Center, DKFZ-ZMBH Alliance, D-69120 Heidelberg, Germany;
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14
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Mavrich TN, Ioshikhes IP, Venters BJ, Jiang C, Tomsho LP, Qi J, Schuster SC, Albert I, Pugh BF. A barrier nucleosome model for statistical positioning of nucleosomes throughout the yeast genome. Genome Res 2008; 18:1073-83. [PMID: 18550805 DOI: 10.1101/gr.078261.108] [Citation(s) in RCA: 503] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Most nucleosomes are well-organized at the 5' ends of S. cerevisiae genes where "-1" and "+1" nucleosomes bracket a nucleosome-free promoter region (NFR). How nucleosomal organization is specified by the genome is less clear. Here we establish and inter-relate rules governing genomic nucleosome organization by sequencing DNA from more than one million immunopurified S. cerevisiae nucleosomes (displayed at http://atlas.bx.psu.edu/). Evidence is presented that the organization of nucleosomes throughout genes is largely a consequence of statistical packing principles. The genomic sequence specifies the location of the -1 and +1 nucleosomes. The +1 nucleosome forms a barrier against which nucleosomes are packed, resulting in uniform positioning, which decays at farther distances from the barrier. We present evidence for a novel 3' NFR that is present at >95% of all genes. 3' NFRs may be important for transcription termination and anti-sense initiation. We present a high-resolution genome-wide map of TFIIB locations that implicates 3' NFRs in gene looping.
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Affiliation(s)
- Travis N Mavrich
- Center for Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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15
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Abstract
The study of insect satellite DNAs (satDNAs) indicates the evolutionary conservation of certain features despite their sequence heterogeneity. Such features can include total length, monomer length, motifs, particular regions and/or secondary and tertiary structures. satDNAs may act as protein-binding sites, structural domains or sites for epigenetic modifications. The selective constraints in the evolution of satDNAs may be due to the satDNA sequence interaction with specific proteins important in heterochromatin formation and possible a role in controlling gene expression. The transcription of satDNA has been described in vertebrates, invertebrates and plants. In insects, differential satDNA expression has been observed in different cells, developmental stages, sex and caste of the individuals. These transcription differences may suggest their involvement in gene-regulation processes. In addition, the satDNA or its transcripts appear to be involved in heterochromatin formation and in chromatin-elimination processes. The importance of transposable elements to insect satDNA is shown by their presence as a constituent of satDNA in several species of insects (including possible active elements). In addition, they may be involved in the formation of centromeres and telomeres and in the homogenization and expansion of satDNA.
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Affiliation(s)
- T Palomeque
- Departamento de Biología Experimental, Area de Genética, Universidad de Jaén, Jaén, Spain.
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16
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Montecino M, Stein JL, Stein GS, Lian JB, van Wijnen AJ, Cruzat F, Gutiérrez S, Olate J, Marcellini S, Gutiérrez JL. Nucleosome organization and targeting of SWI/SNF chromatin-remodeling complexes: contributions of the DNA sequence. Biochem Cell Biol 2008; 85:419-25. [PMID: 17713577 DOI: 10.1139/o07-070] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chromatin organization within the nuclear compartment is a fundamental mechanism to regulate the expression of eukaryotic genes. During the last decade, a number of nuclear protein complexes with the ability to remodel chromatin and regulate gene transcription have been reported. Among these complexes is the SWI/SNF family, which alters chromatin structure in an ATP-dependent manner. A considerable effort has been made to understand the molecular mechanisms by which SWI/SNF catalyzes nucleosome remodeling. However, limited attention has been dedicated to studying the role of the DNA sequence in this remodeling process. Therefore, in this minireview, we discuss the contribution of nucleosome positioning and nucleosome excluding sequences to the targeting and activity of SWI/SNF complexes. This discussion includes results from our group using the rat osteocalcin gene promoter as a model. Based on these results, we postulate a model for chromatin remodeling and transcriptional activation of this gene in osteoblastic cells.
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Affiliation(s)
- Martin Montecino
- Departamento de Bioquimica y Biologia Molecular, Facultad de Ciencias Biologicas, Universidad de Concepcion, Casilla 160-C, Concepcion, Chile.
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17
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Rippe K, Schrader A, Riede P, Strohner R, Lehmann E, Längst G. DNA sequence- and conformation-directed positioning of nucleosomes by chromatin-remodeling complexes. Proc Natl Acad Sci U S A 2007; 104:15635-40. [PMID: 17893337 PMCID: PMC2000439 DOI: 10.1073/pnas.0702430104] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Chromatin-remodeling complexes can translocate nucleosomes along the DNA in an ATP-coupled reaction. This process is an important regulator of all DNA-dependent processes because it determines whether certain DNA sequences are found in regions between nucleosomes with increased accessibility for other factors or wrapped around the histone octamer complex. In a comparison of seven different chromatin-remodeling machines (ACF, ISWI, Snf2H, Chd1, Mi-2, Brg1, and NURF), it is demonstrated that these complexes can read out DNA sequence features to establish specific nucleosome-positioning patterns. For one of the remodelers, ACF, we identified a 40-bp DNA sequence element that directs nucleosome positioning. Furthermore, we show that nucleosome positioning by the remodelers ACF and Chd1 is determined by a reduced affinity to the end product of the translocation reaction. The results suggest that the linkage of differential remodeling activities with the intrinsic binding preferences of nucleosomes can result in establishing distinct chromatin structures that depend on the DNA sequence and define the DNA accessibility for other protein factors.
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Affiliation(s)
- Karsten Rippe
- *Division of Genome Organization and Function, Deutsches Krebsforschungszentrum and Bioquant, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Anna Schrader
- Biochemie III, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Philipp Riede
- Biochemie III, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Ralf Strohner
- Biochemie III, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Elisabeth Lehmann
- Gene Center Munich, Department of Chemistry and Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany; and
| | - Gernot Längst
- Biochemie III, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
- To whom correspondence should be addressed. E-mail:
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Ford J, Odeyale O, Eskandar A, Kouba N, Shen CH. A SWI/SNF- and INO80-dependent nucleosome movement at the INO1 promoter. Biochem Biophys Res Commun 2007; 361:974-9. [PMID: 17681272 PMCID: PMC2034749 DOI: 10.1016/j.bbrc.2007.07.109] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Accepted: 07/20/2007] [Indexed: 01/27/2023]
Abstract
Transcriptional activation in yeast INO1 chromatin was studied using the indirect end-labeling technique. INO1 chromatin is organized into an ordered, overlapping nucleosomal array under repressing conditions. Nucleosome positions were only disrupted at the promoter region under inducing conditions in the presence of SWI/SNF and INO80. Mutants lacking either remodeler demonstrated identical positioning patterns as the wild type under repressing conditions. This indicates that these two remodelers are responsible and essential for local nucleosomal mobilization at the INO1 promoter. The area of local nucleosome movement is consistent with the previously identified region of histone deacetylation activity. In light of these findings, we suggest that nucleosomes subject to local mobilization are also targets for local histone modifications.
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Affiliation(s)
- Jason Ford
- Department of Biology, College of Staten Island, City University of New York, Staten Island, New York 10314, USA
| | - Oluwafemi Odeyale
- Department of Biology, College of Staten Island, City University of New York, Staten Island, New York 10314, USA
| | - Antonious Eskandar
- Department of Biology, College of Staten Island, City University of New York, Staten Island, New York 10314, USA
| | - Nafila Kouba
- Department of Biology, College of Staten Island, City University of New York, Staten Island, New York 10314, USA
| | - Chang-Hui Shen
- Department of Biology, College of Staten Island, City University of New York, Staten Island, New York 10314, USA
- Institute for Macromolecular Assemblies, City University of New York, Staten Island, New York 10314, USA
- To whom correspondence should be addressed. Phone: 718-982-3998. Fax: (718) 982-3852. E-mail:
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19
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Peckham HE, Thurman RE, Fu Y, Stamatoyannopoulos JA, Noble WS, Struhl K, Weng Z. Nucleosome positioning signals in genomic DNA. Genome Res 2007; 17:1170-7. [PMID: 17620451 PMCID: PMC1933512 DOI: 10.1101/gr.6101007] [Citation(s) in RCA: 245] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Although histones can form nucleosomes on virtually any genomic sequence, DNA sequences show considerable variability in their binding affinity. We have used DNA sequences of Saccharomyces cerevisiae whose nucleosome binding affinities have been experimentally determined (Yuan et al. 2005) to train a support vector machine to identify the nucleosome formation potential of any given sequence of DNA. The DNA sequences whose nucleosome formation potential are most accurately predicted are those that contain strong nucleosome forming or inhibiting signals and are found within nucleosome length stretches of genomic DNA with continuous nucleosome formation or inhibition signals. We have accurately predicted the experimentally determined nucleosome positions across a well-characterized promoter region of S. cerevisiae and identified strong periodicity within 199 center-aligned mononucleosomes studied recently (Segal et al. 2006) despite there being no periodicity information used to train the support vector machine. Our analysis suggests that only a subset of nucleosomes are likely to be positioned by intrinsic sequence signals. This observation is consistent with the available experimental data and is inconsistent with the proposal of a nucleosome positioning code. Finally, we show that intrinsic nucleosome positioning signals are both more inhibitory and more variable in promoter regions than in open reading frames in S. cerevisiae.
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Affiliation(s)
- Heather E. Peckham
- Bioinformatics Program, Boston University, Boston, Massachusetts 02215, USA
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, USA
| | - Robert E. Thurman
- Division of Medical Genetics, University of Washington, Seattle, Washington 98195, USA
| | - Yutao Fu
- Bioinformatics Program, Boston University, Boston, Massachusetts 02215, USA
| | | | - William Stafford Noble
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA
- Department of Computer Science and Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Kevin Struhl
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Zhiping Weng
- Bioinformatics Program, Boston University, Boston, Massachusetts 02215, USA
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, USA
- Corresponding author.E-mail ; fax (617) 353-6766
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20
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Pusarla RH, Vinayachandran V, Bhargava P. Nucleosome positioning in relation to nucleosome spacing and DNA sequence-specific binding of a protein. FEBS J 2007; 274:2396-410. [PMID: 17419736 DOI: 10.1111/j.1742-4658.2007.05775.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Nucleosome positioning is an important mechanism for the regulation of eukaryotic gene expression. Folding of the chromatin fiber can influence nucleosome positioning, whereas similar electrostatic mechanisms govern the nucleosome repeat length and chromatin fiber folding in vitro. The position of the nucleosomes is directed either by the DNA sequence or by the boundaries created due to the binding of certain trans-acting factors to their target sites in the DNA. Increasing ionic strength results in an increase in nucleosome spacing on the chromatin assembled by the S-190 extract of Drosophila embryos. In this study, a mutant lac repressor protein R3 was used to find the mechanisms of nucleosome positioning on a plasmid with three R3-binding sites. With increasing ionic strength in the presence of R3, the number of positioned nucleosomes in the chromatin decreased, whereas the internucleosomal spacings of the positioned nucleosomes in a single register did not change. The number of the positioned nucleosomes in the chromatin assembled in vitro over different plasmid DNAs with 1-3 lac operators changed with the relative position and number of the R3-binding sites. We found that in the presence of R3, nucleosomes were positioned in the salt gradient method of the chromatin assembly, even in the absence of a nucleosome-positioning sequence. Our results show that nucleosome-positioning mechanisms are dominant, as the nucleosomes can be positioned even in the absence of regular spacing mechanisms. The protein-generated boundaries are more effective when more than one binding site is present with a minimum distance of approximately 165 bp, greater than the nucleosome core DNA length, between them.
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21
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Ong MS, Richmond TJ, Davey CA. DNA stretching and extreme kinking in the nucleosome core. J Mol Biol 2007; 368:1067-74. [PMID: 17379244 DOI: 10.1016/j.jmb.2007.02.062] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Revised: 02/06/2007] [Accepted: 02/16/2007] [Indexed: 11/25/2022]
Abstract
DNA stretching in chromatin may facilitate its compaction and influence site recognition by nuclear factors. In vivo, stretching has been estimated to occur at the equivalent of one to two base-pairs (bp) per nucleosome. We have determined the crystal structure of a nucleosome core particle containing 145 bp of DNA (NCP145). Compared to the structure with 147 bp, the NCP145 displays two incidences of stretching one to two double-helical turns from the particle dyad axis. The stretching illustrates clearly a mechanism for shifting DNA position by displacement of a single base-pair while maintaining nearly identical histone-DNA interactions. Increased DNA twist localized to a short section between adjacent histone-DNA binding sites advances the rotational setting, while a translational component involves DNA kinking at a flanking region that initiates elongation by unstacking bases. Furthermore, one stretched region of the NCP145 displays an extraordinary 55 degrees kink into the minor groove situated 1.5 double-helical turns from the particle dyad axis, a hot spot for gene insertion by HIV-integrase, which prefers highly distorted substrate. This suggests that nucleosome position and context within chromatin could promote extreme DNA kinking that may influence genomic processes.
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Affiliation(s)
- Michelle S Ong
- Division of Structural and Computational Biology, School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
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22
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Li J, Längst G, Grummt I. NoRC-dependent nucleosome positioning silences rRNA genes. EMBO J 2006; 25:5735-41. [PMID: 17139253 PMCID: PMC1698900 DOI: 10.1038/sj.emboj.7601454] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Accepted: 10/25/2006] [Indexed: 12/29/2022] Open
Abstract
Previous studies have established that the Snf2h-containing chromatin remodeling complex NoRC mediates epigenetic silencing of a subset of rRNA genes (rDNA) by recruiting enzymatic activities that modify histones and methylate DNA. Here we have analyzed nucleosome positions at the murine rDNA promoter and show that active and silent rDNA copies are characterized not only by specific epigenetic marks but also by differently positioned nucleosomes. At active genes the promoter-bound nucleosome covers nucleotides from -157 to -2, whereas at silent genes the nucleosome is positioned 25 nucleotides further downstream. We provide evidence that NoRC is the molecular machine that shifts the promoter-bound nucleosome downstream of the transcription start site into a translational position that is unfavorable for transcription complex formation.
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Affiliation(s)
- Junwei Li
- German Cancer Research Center, Division of Molecular Biology of the Cell II, Heidelberg, Germany
| | - Gernot Längst
- Institut für Biochemie, Genetik und Mikrobiologie, Regensburg, Germany
| | - Ingrid Grummt
- German Cancer Research Center, Division of Molecular Biology of the Cell II, Heidelberg, Germany
- Molecular Biology of the Cell II, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. Tel.: +49 6221 423423; Fax: +49 6221 423404; E-mail:
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23
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Fraser RM, Allan J, Simmen MW. In silico approaches reveal the potential for DNA sequence-dependent histone octamer affinity to influence chromatin structure in vivo. J Mol Biol 2006; 364:582-98. [PMID: 17027853 DOI: 10.1016/j.jmb.2006.08.092] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 08/29/2006] [Accepted: 08/31/2006] [Indexed: 11/30/2022]
Abstract
Nucleosome positioning signals embedded within the DNA sequence have the potential to influence the detailed structure of the higher-order chromatin fibre. In two previous studies of long stretches of DNA, encompassing the chicken beta-globin and ovine beta-lactoglobulin genes, respectively, we mapped the relative affinity of every site for the core histone octamer. In both cases a periodic arrangement of the in vitro positioning sites suggests that they might influence the folding of a nucleosome chain into higher-order structure; this hypothesis was borne out in the case of the beta-lactoglobulin gene, where the distribution of the in vitro positioning sites is related to the positions nucleosomes actually occupy in sheep liver cells. Here, we have exploited the in vitro nucleosome positioning datasets to simulate nucleosomal organisation using in silico approaches. We use the high-resolution, quantitative positioning maps to define a one-dimensional positioning energy lattice, which can be populated with a defined number of nucleosomes. Monte Carlo techniques are employed to simulate the behaviour of the model at equilibrium to produce a set of configurations, which provide a probability-based occupancy map. Employing a variety of techniques we show that the occupancy maps are a sensitive function of the histone octamer density (nucleosome repeat length) and find that a minimal change in this property can produce dramatic localised changes in structure. Although simulations generally give rise to regular periodic nucleosomal arrangements, they often show octamer density-dependent discontinuities, which tend to co-localise with sequences that adopt distinctive chromatin structure in vivo. Furthermore, the overall organisation of simulated chromatin structures are more closely related to the situation in vivo than is the original in vitro positioning data, particularly at a nucleosome density corresponding to the in vivo state. Although our model is simplified, we argue that it provides a unique insight into the influence that DNA sequence can have in determining chromatin structure and could serve as a useful basis for the incorporation of other parameters.
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Affiliation(s)
- Ross M Fraser
- School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
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24
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Gencheva M, Boa S, Fraser R, Simmen MW, A Whitelaw CB, Allan J. In Vitro and in Vivo nucleosome positioning on the ovine beta-lactoglobulin gene are related. J Mol Biol 2006; 361:216-30. [PMID: 16859709 DOI: 10.1016/j.jmb.2006.06.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 06/06/2006] [Accepted: 06/11/2006] [Indexed: 10/24/2022]
Abstract
Although positioned nucleosomes are known to play a direct, localised role in regulating access to DNA sequence, they also have the potential, through their long-range distribution, to affect the detailed structure of the higher-order chromatin fibre. To investigate this possibility, we firstly mapped, in vitro, the sequence-dependent positions that the core histone octamer adopts when reconstituted onto DNA containing the ovine beta-lactoglobulin gene. These positioning sites are discussed in terms of their relative affinity for the histone octamer, their locations with respect to the gene sequence and their periodic distribution throughout the gene region. Secondly, we mapped, in vivo, the sites that nucleosomes occupy on the same sequence in liver nuclei, where the gene is transcriptionally inactive. Although the sequence is largely packaged into regularly spaced nucleosomes, reflecting a fibre of uniform higher-order structure, this organisation is disrupted by a number of unusual chromatin structures in a region stretching from the second to the third introns of the gene. A comparison of the in vitro and in vivo nucleosome positioning data shows that they are qualitatively and quantitatively related, suggesting that the structure of the higher-order chromatin fibre containing the beta-lactoglobulin gene is determined, in part, by the long-range organisation of the non-coding sequences within which the gene is embedded.
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Affiliation(s)
- Marieta Gencheva
- Institute of Structural and Molecular Biology, University of Edinburgh, Darwin Building, King's Buildings, West Mains Road, Edinburgh EH9 3JR, UK
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25
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Dohi Y, Alam J, Yoshizumi M, Sun J, Igarashi K. Heme oxygenase-1 gene enhancer manifests silencing activity in a chromatin environment prior to oxidative stress. Antioxid Redox Signal 2006; 8:60-7. [PMID: 16487038 DOI: 10.1089/ars.2006.8.60] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The expression of heme oxygenase-1 (HO-1) is regulated by E1 and E2 enhancers, both of which contain multiple Maf recognition elements (MAREs). In living cells, MAREs are bound by Bach1/MafK heterodimers, hence maintaining a quiescent state of the HO-1 gene (hmox-1). However, in transient transfection assays, they act as transcriptional enhancers. Therefore MAREs may manifest their function only in a chromatin environment. By using NIH3T3 cell pools stably transfected with EGFP reporter genes driven by the wild-type or mutated E2 enhancer, we demonstrate that the E2 MAREs function as transcriptional silencers depending on the binding of Bach1/MafK heterodimer in vivo only in a chromatin environment. After cadmium treatment, they switched into transcriptional enhancers. Surprisingly, single MARE site did not exhibit such function. Furthermore, by using DNase I hypersensitivity assay, we demonstrate that simple chromatin condensations were not involved in the Bach1-mediated repression. We conclude that, in a chromatin environment, the E2 MAREs function as transcriptional silencers depending on binding of Bach1/MafK heterodimer.
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Affiliation(s)
- Yoshihiro Dohi
- Department of Biomedical Chemistry, Hiroshima University Graduate School of Biomedical Science, Hiroshima, Japan
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26
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West KL, Singha NC, De Ioannes P, Lacomis L, Erdjument-Bromage H, Tempst P, Cortes P. A direct interaction between the RAG2 C terminus and the core histones is required for efficient V(D)J recombination. Immunity 2005; 23:203-12. [PMID: 16111638 DOI: 10.1016/j.immuni.2005.07.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2005] [Revised: 06/01/2005] [Accepted: 07/13/2005] [Indexed: 11/18/2022]
Abstract
V(D)J recombination is a tightly controlled process of somatic recombination whose regulation is mediated in part by chromatin structure. Here, we report that RAG2 binds directly to the core histone proteins. The interaction with histones is observed in developing lymphocytes and within the RAG1/RAG2 recombinase complex in a manner that is dependent on the RAG2 C terminus. Amino acids within the plant homeo domain (PHD)-like domain as well as a conserved acidic stretch of the RAG2 C terminus that is considered to be a linker region are important for this interaction. Point mutations that disrupt the RAG2-histone association inhibit the efficiency of the V(D)J recombination reaction at the endogenous immunoglobulin locus, with the most dramatic effect in the V to DJ(H) rearrangement.
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Affiliation(s)
- Kelly L West
- Immunobiology Center, Mount Sinai School of Medicine, New York, New York 10029, USA
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27
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Cohanim AB, Kashi Y, Trifonov EN. Yeast nucleosome DNA pattern: deconvolution from genome sequences of S. cerevisiae. J Biomol Struct Dyn 2005; 22:687-94. [PMID: 15842173 DOI: 10.1080/07391102.2005.10507035] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Positional correlation analysis for the complete genome of Saccharomyces cerevisiae is performed with the aim to reveal possible chromatin-related sequence features. A strong periodicity with the period 10.4 bases is detected in the distance histograms for the dinucleotides AA and TT, with the characteristic decay distance of approximately 50 base pairs. The oscillations are observed as well in the distributions of other dinucleotides. However, the respective amplitudes are small, consistent with secondary effects, due to dominant periodicity of AA and TT. The observations are in accord with earlier data on the chromatin sequence periodicities and nucleosome DNA sequence patterns. The autocorrelations of AA and TT dinucleotides in yeast include also a counter-phase component. A tentative DNA sequence pattern for the yeast nucleosomes is suggested and verified by comparison of its autocorrelation plots with the respective natural autocorrelations. The nucleosome mapping guided by the pattern is in accord with experimental data on the linker length distribution in yeast.
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Affiliation(s)
- Amir B Cohanim
- Department of Biotechnology and Food Engineering, Technion, Haifa 32000, Israel
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28
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Tsunaka Y, Kajimura N, Tate SI, Morikawa K. Alteration of the nucleosomal DNA path in the crystal structure of a human nucleosome core particle. Nucleic Acids Res 2005; 33:3424-34. [PMID: 15951514 PMCID: PMC1150222 DOI: 10.1093/nar/gki663] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Gene expression in eukaryotes depends upon positioning, mobility and packaging of nucleosomes; thus, we need the detailed information of the human nucleosome core particle (NCP) structure, which could clarify chromatin properties. Here, we report the 2.5 A crystal structure of a human NCP. The overall structure is similar to those of other NCPs reported previously. However, the DNA path of human NCP is remarkably different from that taken within other NCPs with an identical DNA sequence. A comparison of the structural parameters between human and Xenopus laevis DNA reveals that the DNA path of human NCP consecutively shifts by 1 bp in the regions of superhelix axis location -5.0 to -2.0 and 5.0 to 7.0. This alteration of the human DNA path is caused predominantly by tight DNA-DNA contacts within the crystal. It is also likely that the conformational change in the human H2B tail induces the local alteration of the DNA path. In human NCP, the region with the altered DNA path lacks Mn2+ ions and the B-factors of the DNA phosphate groups are substantially high. Therefore, in contrast to the histone octamer, the nucleosomal DNA is sufficiently flexible and mobile and can undergo drastic conformational changes, depending upon the environment.
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Affiliation(s)
| | | | | | - Kosuke Morikawa
- To whom correspondence should be addressed. Tel: +81 6 6872 8211; Fax: +81 6 6872 8210;
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29
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Komura JI, Ono T. Disappearance of nucleosome positioning in mitotic chromatin in vivo. J Biol Chem 2005; 280:14530-5. [PMID: 15705567 DOI: 10.1074/jbc.m500637200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
During mitosis, transcription is silenced and most transcription factors are displaced from their recognition sequences. By in vivo footprinting analysis, we have confirmed and extended previous studies showing loss of transcription factors from an RNA polymerase II promoter (c-FOS) and, for the first time, an RNA polymerase III promoter (U6) in HeLa cells. Because little was known about nucleosomal organization in mitotic chromosomes, we performed footprinting analysis for nucleosomes on these promoters in interphase and mitotic cells. During interphase, each of the promoters had a positioned nucleosome in the region intervening between proximal promoter elements and distal enhancer elements, but the strong nucleosome positioning disappeared during mitosis. Thus, the nucleosomal organization that appears to facilitate transcription in interphase cells may be lost in mitotic cells, and nucleosome positioning during mitosis does not seem to be a major component of the epigenetic mechanisms to mark genes for rapid reactivation after this phase.
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Affiliation(s)
- Jun-ichiro Komura
- Department of Cell Biology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan.
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30
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Yarragudi A, Miyake T, Li R, Morse RH. Comparison of ABF1 and RAP1 in chromatin opening and transactivator potentiation in the budding yeast Saccharomyces cerevisiae. Mol Cell Biol 2004; 24:9152-64. [PMID: 15456886 PMCID: PMC517901 DOI: 10.1128/mcb.24.20.9152-9164.2004] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Autonomously replicating sequence binding factor 1 (ABF1) and repressor/activator protein 1 (RAP1) from budding yeast are multifunctional, site-specific DNA-binding proteins, with roles in gene activation and repression, replication, and telomere structure and function. Previously we have shown that RAP1 can prevent nucleosome positioning in the vicinity of its binding site and have provided evidence that this ability to create a local region of "open" chromatin contributes to RAP1 function at the HIS4 promoter by facilitating binding and activation by GCN4. Here we examine and directly compare to that of RAP1 the ability of ABF1 to create a region of open chromatin near its binding site and to contribute to activated transcription at the HIS4, ADE5,7, and HIS7 promoters. ABF1 behaves similarly to RAP1 in these assays, but it shows some subtle differences from RAP1 in the character of the open chromatin region near its binding site. Furthermore, although the two factors can similarly enhance activated transcription at the promoters tested, RAP1 binding is continuously required for this enhancement, but ABF1 binding is not. These results indicate that ABF1 and RAP1 achieve functional similarity in part via mechanistically distinct pathways.
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31
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Belikov S, Holmqvist PH, Astrand C, Wrange O. Nuclear Factor 1 and Octamer Transcription Factor 1 Binding Preset the Chromatin Structure of the Mouse Mammary Tumor Virus Promoter for Hormone Induction. J Biol Chem 2004; 279:49857-67. [PMID: 15381691 DOI: 10.1074/jbc.m409713200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
When the mouse mammary tumor virus (MMTV) is integrated into the genome of a mammalian cell, its long terminal repeat (LTR) harbors six specifically positioned nucleosomes. Transcription from the MMTV promoter is regulated by the glucocorticoid hormone via the glucocorticoid receptor (GR). The mechanism of the apparently constitutive nucleosome arrangement has remained unclear. Previous in vitro reconstitution of nucleosome(s) on small segments of the MMTV LTR suggested that the DNA sequence was decisive for the nucleosome arrangement. However, microinjection of MMTV LTR DNA in Xenopus oocytes rendered randomly distributed nucleosomes. This indicated that oocytes lack factor(s) that induces nucleosome positioning at the MMTV LTR in other cells. Here we demonstrate that specific and concomitant binding of nuclear factor 1 (NF1) and octamer factor 1 (Oct1) to their cognate sites within the MMTV promoter induce a partial nucleosome positioning that is an intermediary state between the randomly organized inactive promoter and the hormone and GR-activated promoter containing distinctly positioned nucleosomes. Oct1 and NF1 reciprocally facilitate each other's binding to the MMTV LTR in vivo. The NF1 and Oct1 binding also facilitate hormone-dependent GR-DNA interaction and result in a faster and stronger hormone response. Since NF1 and Oct1 generate an intermediary state of nucleosome positioning and enhance the hormone-induced response, we refer to this as a preset chromatin structure. We propose that this state of NF1 and Oct1-induced chromatin presetting mimics the early step(s) of chromatin remodeling involved in tissue-specific gene expression.
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Affiliation(s)
- Sergey Belikov
- Department of Cell and Molecular Biology, The Medical Nobel Institute, P. O. Box 285, Karolinska Institutet, Stockholm SE-17177, Sweden
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32
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Yu L, Yu C, Stafford G, Morse RH. Competition Between Transcription Factors and Histones, and the Role of the Histone H3 Amino Terminus, During Gene Regulation in Budding Yeast. J CHIN CHEM SOC-TAIP 2004. [DOI: 10.1002/jccs.200400173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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33
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Davey CS, Pennings S, Reilly C, Meehan RR, Allan J. A determining influence for CpG dinucleotides on nucleosome positioning in vitro. Nucleic Acids Res 2004; 32:4322-31. [PMID: 15310836 PMCID: PMC514372 DOI: 10.1093/nar/gkh749] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
DNA sequence information that directs the translational positioning of nucleosomes can be attenuated by cytosine methylation when a short run of CpG dinucleotides is located close to the dyad axis of the nucleosome. Here, we show that point mutations introduced to re-pattern methylation at the (CpG)3 element in the chicken betaA-globin promoter sequence themselves strongly influenced nucleosome formation in reconstituted chromatin. The disruptive effect of cytosine methylation on nucleosome formation was found to be determined by the sequence context of CpG dinucleotides, not just their location in the positioning sequence. Additional mutations indicated that methylation can also promote the occupation of certain nucleosome positions. DNase I analysis demonstrated that these genetic and epigenetic modifications altered the structural characteristics of the (CpG)3 element. Our findings support a proposal that the intrinsic structural properties of the DNA at the -1.5 site, as occupied by (CpG)3 in the nucleosome studied, can be decisive for nucleosome formation and stability, and that changes in anisotropic DNA bending or flexibility at this site explain why nucleosome positioning can be exquisitely sensitive to genetic and epigenetic modification of the DNA sequence.
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Affiliation(s)
- Colin S Davey
- Institute of Cell and Molecular Biology, University of Edinburgh, Darwin Building, King's Buildings, West Mains Road, Edinburgh EH9 3JR, UK
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34
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Thåström A, Bingham LM, Widom J. Nucleosomal locations of dominant DNA sequence motifs for histone-DNA interactions and nucleosome positioning. J Mol Biol 2004; 338:695-709. [PMID: 15099738 DOI: 10.1016/j.jmb.2004.03.032] [Citation(s) in RCA: 156] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2004] [Revised: 03/15/2004] [Accepted: 03/15/2004] [Indexed: 10/26/2022]
Abstract
DNA sequence is an important determinant of the positioning, stability, and activity of nucleosomes, yet the molecular basis of these effects remains elusive. A "consensus DNA sequence" for nucleosome positioning has not been reported and, while certain DNA sequence preferences or motifs for nucleosome positioning have been discovered, how they function is not known. Here, we report that an unexpected observation concerning the reassembly of nucleosomes during salt gradient dialysis has allowed a breakthrough in our efforts to identify the nucleosomal locations of the DNA sequence motifs that dominate histone-DNA interactions and nucleosome positioning. We conclude that a previous selection experiment for high-affinity, nucleosome-forming DNA sequences exerted selective pressure chiefly on the central stretch of the nucleosomal DNA. This observation implies that algorithms for aligning the selected DNA sequences should seek to optimize the alignment over much less than the full 147 bp of nucleosomal DNA. A new alignment calculation implemented these ideas and successfully aligned 19 of the 41 sequences in a non-redundant database of selected high-affinity, nucleosome-positioning sequences. The resulting alignment reveals strong conservation of several stretches within a central 71 bp of the nucleosomal DNA. The alignment further reveals an inherent palindromic symmetry in the selected DNAs; it makes testable predictions of nucleosome positioning on the aligned sequences and for the creation of new positioning sequences, both of which are upheld experimentally; and it suggests new signals that may be important in translational nucleosome positioning.
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Affiliation(s)
- A Thåström
- Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, 2153 Sheridan Road, Evanston, IL 60208-3500, USA
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35
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Kim Y, Shen CH, Clark DJ. Purification and nucleosome mapping analysis of native yeast plasmid chromatin. Methods 2004; 33:59-67. [PMID: 15039088 DOI: 10.1016/j.ymeth.2003.10.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2003] [Indexed: 10/26/2022] Open
Abstract
There is much evidence indicating the importance in gene regulation of the positions of nucleosomes with respect to DNA sequence. Low resolution chromatin structures have been described for many genes, but there is a dearth of detailed high resolution chromatin structures. In the cases where they are available, high resolution maps have revealed much more complex chromatin structures, with multiple alternative nucleosome positions. The discovery that ATP-dependent chromatin remodelling machines are recruited to genes, with their ability to mobilise nucleosomes on DNA and to alter nucleosomal conformation, emphasises the necessity for obtaining high resolution nucleosome maps, so that the details of these remodelling reactions can be defined in vivo. Here, we describe protocols for purifying plasmid chromatin from cells of the yeast Saccharomyces cerevisiae and for mapping nucleosome positions on the plasmid using the monomer extension mapping method. This method requires purified chromatin, but is capable of mapping relatively long stretches of chromatin in great detail. Typically, it reveals very complex chromatin structures.
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Affiliation(s)
- Yeonjung Kim
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Building 50 Room 3148, 50 South Drive MSC 8028, Bethesda, MD 20892-8028, USA
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Audit B, Vaillant C, Arnéodo A, d'Aubenton-Carafa Y, Thermes C. Wavelet Analysis of DNA Bending Profiles reveals Structural Constraints on the Evolution of Genomic Sequences. J Biol Phys 2004; 30:33-81. [PMID: 23345861 PMCID: PMC3456503 DOI: 10.1023/b:jobp.0000016438.86794.8e] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Analyses of genomic DNA sequences have shown in previous works that base pairs are correlated at large distances with scale-invariant statistical properties. We show in the present study that these correlations between nucleotides (letters) result in fact from long-range correlations (LRC) between sequence-dependent DNA structural elements (words) involved in the packaging of DNA in chromatin. Using the wavelet transform technique, we perform a comparative analysis of the DNA text and of the corresponding bending profiles generated with curvature tables based on nucleosome positioning data. This exploration through the optics of the so-called `wavelet transform microscope' reveals a characteristic scale of 100-200 bp that separates two regimes of different LRC. We focus here on the existence of LRC in the small-scale regime (≲ 200 bp). Analysis of genomes in the three kingdoms reveals that this regime is specifically associated to the presence of nucleosomes. Indeed, small scale LRC are observed in eukaryotic genomes and to a less extent in archaeal genomes, in contrast with their absence in eubacterial genomes. Similarly, this regime is observed in eukaryotic but not in bacterial viral DNA genomes. There is one exception for genomes of Poxviruses, the only animal DNA viruses that do not replicate in the cell nucleus and do not present small scale LRC. Furthermore, no small scale LRC are detected in the genomes of all examined RNA viruses, with one exception in the case of retroviruses. Altogether, these results strongly suggest that small-scale LRC are a signature of the nucleosomal structure. Finally, we discuss possible interpretations of these small-scale LRC in terms of the mechanisms that govern the positioning, the stability and the dynamics of the nucleosomes along the DNA chain. This paper is maily devoted to a pedagogical presentation of the theoretical concepts and physical methods which are well suited to perform a statistical analysis of genomic sequences. We review the results obtained with the so-called wavelet-based multifractal analysis when investigating the DNA sequences of various organisms in the three kingdoms. Some of these results have been announced in B. Audit et al. [1, 2].
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Affiliation(s)
- Benjamin Audit
- Centre de Recherche Paul Pascal, avenue Schweitzer, 33600 Pessac, France
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37
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Vitolo JM, Yang Z, Basavappa R, Hayes JJ. Structural features of transcription factor IIIA bound to a nucleosome in solution. Mol Cell Biol 2004; 24:697-707. [PMID: 14701742 PMCID: PMC343799 DOI: 10.1128/mcb.24.2.697-707.2004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Assembly of a DNA fragment containing a Xenopus borealis somatic-type 5S RNA gene into a nucleosome greatly restricts binding of the 5S gene-specific transcription factor IIIA (TFIIIA) to the 5S internal promoter. However, TFIIIA binds with high affinity to 5S nucleosomes lacking the N-terminal tail domains of the core histones or to nucleosomes in which these domains are hyperacetylated. The degree to which tail acetylation or removal improves TFIIIA binding cannot be simply explained by a commensurate change in the general accessibility of nucleosomal DNA. In order to investigate the molecular basis of how TFIIIA binds to the nucleosome and to ascertain if binding involves all nine zinc fingers and/or displacement of histone-DNA interactions, we examined the TFIIIA-nucleosome complex by hydroxyl radical footprinting and site-directed protein-DNA cross-linking. Our data reveal that the first six fingers of TFIIIA bind and displace approximately 20 bp of histone-DNA interactions at the periphery of the nucleosome, while binding of fingers 7 to 9 appears to overlap with histone-DNA interactions. Molecular modeling based on these results and the crystal structures of a nucleosome core and a TFIIIA-DNA cocomplex yields a precise picture of the ternary complex and a potentially important intermediate in the transition from naïve chromatin structure to productive polymerase III transcription complex.
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Affiliation(s)
- Joseph M Vitolo
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY 14625, USA
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38
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Gilbert N, Gilchrist S, Bickmore WA. Chromatin organization in the mammalian nucleus. INTERNATIONAL REVIEW OF CYTOLOGY 2004; 242:283-336. [PMID: 15598472 DOI: 10.1016/s0074-7696(04)42007-5] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mammalian cells package their DNA into chromatin and arrange it in the nucleus as chromosomes. In interphase cells chromosomes are organized in a radial distribution with the most gene-dense chromosomes toward the center of the nucleus. Gene transcription, replication, and repair are influenced by the underlying chromatin architecture, which in turn is affected by the formation of chromosome territories. This arrangement in the nucleus presumably facilitates cellular functions to occur in an efficient and ordered fashion and exploring the link between transcription and nuclear organization will be an exciting area of further research.
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Affiliation(s)
- Nick Gilbert
- MRC Human Genetics Unit, Western General Hospital, Edinburgh EH4 2XU, UK
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39
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Richmond TJ, Davey CA. The structure of DNA in the nucleosome core. Nature 2003; 423:145-50. [PMID: 12736678 DOI: 10.1038/nature01595] [Citation(s) in RCA: 880] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2003] [Accepted: 03/12/2003] [Indexed: 01/30/2023]
Abstract
The 1.9-A-resolution crystal structure of the nucleosome core particle containing 147 DNA base pairs reveals the conformation of nucleosomal DNA with unprecedented accuracy. The DNA structure is remarkably different from that in oligonucleotides and non-histone protein-DNA complexes. The DNA base-pair-step geometry has, overall, twice the curvature necessary to accommodate the DNA superhelical path in the nucleosome. DNA segments bent into the minor groove are either kinked or alternately shifted. The unusual DNA conformational parameters induced by the binding of histone protein have implications for sequence-dependent protein recognition and nucleosome positioning and mobility. Comparison of the 147-base-pair structure with two 146-base-pair structures reveals alterations in DNA twist that are evidently common in bulk chromatin, and which are of probable importance for chromatin fibre formation and chromatin remodelling.
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Affiliation(s)
- Timothy J Richmond
- ETH Zürich, Institut für Molekularbiologie und Biophysik, ETH-Hönggerberg, CH-8093 Zürich.
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40
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Hall SE, Kettler G, Preuss D. Centromere satellites from Arabidopsis populations: maintenance of conserved and variable domains. Genome Res 2003; 13:195-205. [PMID: 12566397 PMCID: PMC420371 DOI: 10.1101/gr.593403] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The rapid evolution of centromere sequences between species has led to a debate over whether centromere activity is sequence-dependent. The Arabidopsis thaliana centromere regions contain approximately 20,000 copies of a 178-bp satellite repeat. Here, we analyzed satellites from 41 Arabidopsis ecotypes, providing the first broad population survey of satellite variation within a species. We found highly conserved segments and consistent sequence lengths in the Arabidopsis satellites and in the published collection of human alpha-satellites, supporting models for a functional role. Despite this conservation, polymorphisms are significantly enriched at some sites, yielding variation that could restrict binding proteins to a subset of repeat monomers. Some satellite regions vary considerably; at certain bases, consensus sequences derived from each ecotype diverge significantly from the Arabidopsis consensus, indicating substitutions sweep through a genome in less than 5 million years. Such rapid changes generate more variation within the set of Arabidopsis satellites than in genes from the chromosome arms or from the recombinationally suppressed centromere regions. These studies highlight a balance between the mechanisms that maintain particular satellite domains and the forces that disperse sequence changes throughout the satellite repeats in the genome.
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Affiliation(s)
- Sarah E Hall
- Committee on Genetics, University of Chicago, Chicago, Illinois 60637, USA
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41
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Ye J, Yang Z, Hayes JJ, Eickbush TH. R2 retrotransposition on assembled nucleosomes depends on the translational position of the target site. EMBO J 2002; 21:6853-64. [PMID: 12486006 PMCID: PMC139086 DOI: 10.1093/emboj/cdf665] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
R2 retrotransposons insert into the 28S rRNA genes of insects. Integration occurs by specific cleavage of the target site and utilization of the released DNA end to prime reverse transcription of the RNA transcript. Specificity of the protein to the target site is dependent upon nucleotide sequence recognition extending from 35 bp upstream to 15 bp downstream of the cleavage site. In this report, we show that sequence recognition and cleavage by the R2 protein can occur while the target site is assembled into nucleosomes. Reconstitution of DNA fragments containing the 28S gene sequence into a set of nucleosomes with different translational frames revealed that the R2 site adopted the same rotational orientation with respect to the histone octamer. Binding and cleavage by the R2 protein were most efficient when the upstream binding site for the R2 protein was near a nucleosome end. Interaction of the R2 protein with the nucleosome disrupted the histone:DNA contacts in the 50 bp region directly bound by R2, but did not modify the remainder of the nucleosome structure.
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Affiliation(s)
| | - Zungyoon Yang
- University of Rochester, Department of Biology, Rochester, NY 14627 and
University of Rochester Medical Center, Department of Biochemistry and Biophysics, Rochester, NY 14642, USA Corresponding author e-mail:
| | - Jeffrey J. Hayes
- University of Rochester, Department of Biology, Rochester, NY 14627 and
University of Rochester Medical Center, Department of Biochemistry and Biophysics, Rochester, NY 14642, USA Corresponding author e-mail:
| | - Thomas H. Eickbush
- University of Rochester, Department of Biology, Rochester, NY 14627 and
University of Rochester Medical Center, Department of Biochemistry and Biophysics, Rochester, NY 14642, USA Corresponding author e-mail:
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42
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Paredes R, Gutiérrez J, Gutierrez S, Allison L, Puchi M, Imschenetzky M, van Wijnen A, Lian J, Stein G, Stein J, Montecino M. Interaction of the 1alpha,25-dihydroxyvitamin D3 receptor at the distal promoter region of the bone-specific osteocalcin gene requires nucleosomal remodelling. Biochem J 2002; 363:667-76. [PMID: 11964167 PMCID: PMC1222519 DOI: 10.1042/0264-6021:3630667] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
1alpha,25-Dihydroxyvitamin D3-mediated transcriptional control of the bone-specific osteocalcin (OC) gene requires the integration of regulatory signals at the vitamin D-responsive element (VDRE) and flanking tissue-specific sequences. The 1alpha,25-dihydroxyvitamin D3 receptor (VDR) is a member of the nuclear receptor superfamily and forms a heterodimeric complex with the receptor for 9-cis retinoic acid (RXR) that binds to the VDRE sequence. We have demonstrated previously that changes in chromatin structure at the VDRE region of the rat OC gene promoter accompany transcriptional enhancement in vivo, suggesting a requirement for chromatin remodelling. Here we show that the VDRE in the distal region of the OC gene promoter is refractory to binding of the VDR-RXR complex when organized in a nucleosomal context. Addition of the ligand 1alpha,25-dihydroxyvitamin D3 or the presence of other transcription factors, such as YY1 and Runx/Cbfa (core-binding factor alpha), which also bind to sequences partially overlapping or near the VDRE, is not sufficient to render the VDRE accessible. Thus the VDR-RXR, unlike other steroid receptors, such as glucocorticoid receptor, progesterone receptor and thyroid receptor, is unable to bind its target sequence within a nucleosomal context. Taken together these results demonstrate that nucleosomal remodelling is required for in vivo occupancy of binding sites in the distal region of the OC gene promoter by the regulatory factors responsible for 1alpha,25-dihydroxyvitamin D3-dependent enhancement of transcription.
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Affiliation(s)
- Roberto Paredes
- Departamento de Biologia Molecular, Facultad de Ciencias Biologicas, Universidad de Concepcion, Casilla 160-C, Concepcion, Chile
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43
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Sýkorová E, Fajkus J, Ito M, Fukui K. Transition between two forms of heterochromatin at plant subtelomeres. Chromosome Res 2002; 9:309-23. [PMID: 11419795 DOI: 10.1023/a:1016698713959] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The manner of packing of the terminal DNA loci into nucleosomes and higher order structures may strongly influence their functional interactions. Besides the structural flexibility of telomeric DNA sequences, conserved features of their chromatin including short nucleosome phasing (157 bp) and nucleosome sliding have been described previously. To gain a complementary knowledge of subtelomeres, we have analysed the chromatin structure of two subtelomeric tandem repeats from the plant Silene latifolia: X43.1 and 15Ssp. X43.1 shows two distinct nucleosome periodicities--157 and 188 bp. Preferred positions of its two nucleosomes have been mapped at both low and high resolution and the experimental results correspond to computer-predicted positions. 15Ssp is a newly-discovered sequence showing a telomere-associated position by PCR and a subtelomeric location by pulsed-field gel electrophoresis and fluorescence in situ hybridisation. Its 159 bp sequence unit shows a tandem arrangement and the presence of micrococcal nuclease-hypersensitive sites when either naked DNA or chromatin is digested. Use of a chemical nuclease results in a regular nucleosome ladder of 157 bp periodicity. Moreover, 15Ssp mononucleosomes show instability and absence of specific positioning, features typical for telomeric chromatin.
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Affiliation(s)
- E Sýkorová
- Institute of Biophysics, Czech Academy of Sciences and Department of Analysis of Biologically Important Molecular Complexes, Masaryk University Brno, Czech Republic
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44
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Gilbert N, Allan J. Distinctive higher-order chromatin structure at mammalian centromeres. Proc Natl Acad Sci U S A 2001; 98:11949-54. [PMID: 11593003 PMCID: PMC59820 DOI: 10.1073/pnas.211322798] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The structure of the higher-order chromatin fiber has not been defined in detail. We have used a novel approach based on sucrose gradient centrifugation to compare the conformation of centromeric satellite DNA-containing higher-order chromatin fibers with bulk chromatin fibers obtained from the same mouse fibroblast cells. Our data show that chromatin fibers derived from the centromeric domain of a chromosome exist in a more condensed structure than bulk chromatin whereas pericentromeric chromatin fibers have an intermediate conformation. From the standpoint of current models, our data are interpreted to suggest that satellite chromatin adopts a regular helical conformation compatible with the canonical 30-nm chromatin fiber whereas bulk chromatin fibers appear less regularly folded and are perhaps intermittently interrupted by deformations. This distinctive conformation of the higher-order chromatin fiber in the centromeric domain of the mammalian chromosome could play a role in the formation of heterochromatin and in the determination of centromere identity.
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Affiliation(s)
- N Gilbert
- Institute of Cell and Molecular Biology, University of Edinburgh, Darwin Building, Kings Buildings, West Mains Road, Edinburgh, EH9 3JR, United Kingdom
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45
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Shen CH, Clark DJ. DNA sequence plays a major role in determining nucleosome positions in yeast CUP1 chromatin. J Biol Chem 2001; 276:35209-16. [PMID: 11461917 DOI: 10.1074/jbc.m104733200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The role of DNA sequence in determining nucleosome positions in vivo was investigated by comparing the positions adopted by nucleosomes reconstituted on a yeast plasmid in vitro using purified core histones with those in native chromatin containing the same DNA, described previously. Nucleosomes were reconstituted on a 2.5 kilobase pair DNA sequence containing the yeast TRP1ARS1 plasmid with CUP1 as an insert (TAC-DNA). Multiple, alternative, overlapping nucleosome positions were mapped on TAC-DNA. For the 58 positioned nucleosomes identified, the relative positioning strengths and the stabilities to salt and temperature were determined. These positions were, with a few exceptions, identical to those observed in native, remodeled TAC chromatin containing an activated CUP1 gene. Only some of these positions are utilized in native, unremodeled chromatin. These observations suggest that DNA sequence is likely to play a very important role in positioning nucleosomes in vivo. We suggest that events occurring in yeast CUP1 chromatin determine which positions are occupied in vivo and when they are occupied.
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Affiliation(s)
- C H Shen
- Laboratory of Cellular and Developmental Biology, NIDDK, National Institutes of Health, Bethesda, Maryland 20892, USA
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46
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Ali BM, Amit R, Braslavsky I, Oppenheim AB, Gileadi O, Stavans J. Compaction of single DNA molecules induced by binding of integration host factor (IHF). Proc Natl Acad Sci U S A 2001; 98:10658-63. [PMID: 11535804 PMCID: PMC58522 DOI: 10.1073/pnas.181029198] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2001] [Indexed: 11/18/2022] Open
Abstract
We studied the interaction between the integration host factor (IHF), a major nucleoid-associated protein in bacteria, and single DNA molecules. Force-extension measurements of lambda DNA and an analysis of the Brownian motion of small beads tethered to a surface by single short DNA molecules, in equilibrium with an IHF solution, indicate that: (i) the DNA-IHF complex retains a random, although more compact, coiled configuration for zero or small values of the tension, (ii) IHF induces DNA compaction by binding to multiple DNA sites with low specificity, and (iii) with increasing tension on the DNA, the elastic properties of bare DNA are recovered. This behavior is consistent with the predictions of a statistical mechanical model describing how proteins bending DNA are driven off by an applied tension on the DNA molecule. Estimates of the amount of bound IHF in DNA-IHF complexes obtained from the model agree very well with independent measurements of this quantity obtained from the analysis of DNA-IHF crosslinking. Our findings support the long-held view that IHF and other histone-like proteins play an important role in shaping the long-scale structure of the bacterial nucleoid.
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Affiliation(s)
- B M Ali
- Department of Physics of Complex Systems, the Weizmann Institute of Science, Rehovot 76100, Israel
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47
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Li B, Reese JC. Ssn6-Tup1 regulates RNR3 by positioning nucleosomes and affecting the chromatin structure at the upstream repression sequence. J Biol Chem 2001; 276:33788-97. [PMID: 11448965 DOI: 10.1074/jbc.m104220200] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The DNA damage inducible gene ribonucleotide reductase (RNR3) is regulated by a transcriptional repression mechanism by the recruitment of the Ssn6-Tup1 corepressor complex to its promoter by the sequence-specific DNA-binding protein Crt1. Ssn6-Tup1 is reported to represses transcription by interfering with transcription factors, recruiting histone deacetylases, and positioning nucleosomes at the promoter of its target genes. Two of the three mechanisms involve effects on chromatin structure, and therefore, we have delineated the nucleosomal structure of RNR3 in the repressed and derepressed state using multiple nuclease mapping strategies. A regular array of positioned nucleosomes is detected over the repressed RNR3 promoter that extends into the coding sequence. Treating cells with DNA damaging agents or deleting CRT1, SSN6, or TUP1 derepresses RNR3 transcription, and causes a dramatic disruption of nucleosome positioning over its promoter. Furthermore, derepression of RNR3 correlated with changes in nuclease sensitivity within the upstream repression sequence (URS) region. Specifically, the loss of a MNase-hypersensitive site, and the appearance of strong DNase I hypersensitivity, was observed over the URS. Interestingly, we find that the binding of Crt1 to the promoter in the absence of Ssn6 or Tup1 is insufficient for nucleosome positioning or regulating chromatin structure at the URS; thus, these two functions are strictly dependent upon Ssn6-Tup1. We propose that RNR3 is regulated by changes in nucleosome positioning and chromatin structure that are mediated by Ssn6, Tup1, and Crt1.
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Affiliation(s)
- B Li
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802-4500, USA
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48
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Onishi Y, Kiyama R. Enhancer activity of HS2 of the human beta-LCR is modulated by distance from the key nucleosome. Nucleic Acids Res 2001; 29:3448-57. [PMID: 11504883 PMCID: PMC55842 DOI: 10.1093/nar/29.16.3448] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A class of curved DNA appears universally in eukaryotic genomic DNA at an average distance of approximately 680 bp and shows nucleosome positioning activity by having high affinity for histone core particles in an orientation- and position-dependent manner. Here, we report that the enhancer activity at DNase I hypersensitive site 2 (HS2) of the human beta-globin locus control region (beta-LCR) can be modulated by the curved DNA located at a distance of two nucleosomes from HS2 and that the nucleosome at the curved DNA regulates nearby nucleosome phases as a key nucleosome. Erythroid-specific nucleosome phases which caused deviation of the NF-E2 (p18-p45 dimer) binding site from the nucleosome dyad axis were over-represented when the distance between the key nucleosome and HS2 exceeded 80 bp longer than the original length. At this state, enhancer activity was approximately 50% of that in the original construct, presumably due to reduced binding of transcription factors.
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Affiliation(s)
- Y Onishi
- Institute of Molecular and Cell Biology, AIST Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
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49
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Medina R, Paredes R, Puchi M, Imschenetzky M, Montecino M. Developmentally-regulated interaction of a transcription factor complex containing CDP/cut with the early histone H3 gene promoter of the sea urchin Tetrapygus niger is associated with changes in chromatin structure and gene expression. Gene 2001; 272:237-48. [PMID: 11470530 DOI: 10.1016/s0378-1119(01)00534-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
During sea urchin embryogenesis the early histone genes are temporally expressed to accommodate the high demand for histone proteins during DNA replication at early cleavage stages of development. The early histone genes are transcriptionally active from the 16-cell stage, reaching a peak in expression at the 128-cell stage that gradually decreases until expression is completely inhibited at the late blastula stage. We are studying the gene regulatory mechanisms that control early histone gene expression in sea urchins to understand the interrelationships between chromatin remodeling and transcriptional activation during development. Here, we have investigated chromatin organization and transcription factor interactions by analyzing nuclease hypersensitivity and protein binding in the promoter region of the early histone H3 gene from the sea urchin Tetrapygus niger. We have found a DNase I hypersensitive domain centered at -90 in the early histone H3 gene promoter which is only detected in embryos at the 128-cell stage expressing high levels of early histone H3 mRNA. This hypersensitive site (-110 to -70) encompasses two regulatory elements (TnH3NFH3.1 and TnH3CCAAT). The -94 to -77 region of the histone H3 promoter is recognized by a transcription factor complex in nuclear extracts from 128-cell embryos. Methylation interference analysis and competition studies demonstrated a specific interaction at the CCAAT sequence. Using specific antibodies we find that the homeodomain transcription factor CDP/cut is the DNA-binding component of the complex interacting with the early histone H3 gene promoter in T. niger. Our results provide further evidence for the functional role of CDP/cut in developmental regulation of histone gene expression in phylogenetically diverse eukaryotic species.
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Affiliation(s)
- R Medina
- Departamento de Biologia Molecular, Facultad de Ciencias Biologicas, Universidad de Concepcion, Casilla 160-C, Concepcion, Chile
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50
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Belikov S, Gelius B, Wrange Ö. Hormone-induced nucleosome positioning in the MMTV promoter is reversible. EMBO J 2001; 20:2802-11. [PMID: 11387213 PMCID: PMC125491 DOI: 10.1093/emboj/20.11.2802] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The mouse mammary tumor virus (MMTV) promoter is induced by glucocorticoid hormone via the glucocorticoid receptor (GR). The hormone-triggered effects on MMTV transcription and chromatin structure were studied in Xenopus oocytes. We previously showed that the nucleosomes organizing the MMTV promoter became translationally positioned upon hormone induction. A single GR-binding site was necessary and sufficient for the chromatin events to occur, while transcription and basal promoter elements were dispensable. Here we show that addition of the hormone antagonists RU486 or RU43044 to the previously hormone-induced MMTV promoter results in cessation of transcription and loss of chromatin remodeling and nucleosome positioning. In vivo footprinting demonstrated agonist- and RU486-induced GR binding to its DNA response element (GRE), while the other antagonist, RU43044, did not promote GR-GRE interaction. These results demonstrate that induction and maintenance of nucleosome positioning is an active process that requires constant 'pressure' of agonist-GR-recruited chromatin-modifying factor(s) rather than GR-DNA binding itself.
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Affiliation(s)
- Sergey Belikov
- Department of Cell and Molecular Biology, The Medical Nobel Institute, Box 285, Karolinska Institutet, SE-17177 Stockholm, Sweden and W.A.Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 117984, Russia Corresponding author e-mail:
| | - Birgitta Gelius
- Department of Cell and Molecular Biology, The Medical Nobel Institute, Box 285, Karolinska Institutet, SE-17177 Stockholm, Sweden and W.A.Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 117984, Russia Corresponding author e-mail:
| | - Örjan Wrange
- Department of Cell and Molecular Biology, The Medical Nobel Institute, Box 285, Karolinska Institutet, SE-17177 Stockholm, Sweden and W.A.Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 117984, Russia Corresponding author e-mail:
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