Hitoshi Kurumizaka

Waseda University, Edo, Tōkyō, Japan

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Publications (131)775.97 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Nuclear autoantigenic sperm proteins (NASPs) are members of the acidic histone chaperones, which promote nucleosome assembly. In humans, two splicing variants proposed for the somatic and testicular isoforms, sNASP and tNASP, respectively, have been found, and the shorter form, sNASP, reportedly promotes nucleosome assembly with the histone H3 isoforms, H3.1, H3.2, and H3.3. However, the biochemical properties of the longer form, tNASP, have not been reported. tNASP is considered to exist specifically in the testis. Our present results revealed that the tNASP protein is ubiquitously produced in various human tissues, in addition to testis. Unexpectedly, we found that the nucleosome assembly activity of purified tNASP was extremely low with the canonical histone H3.1 or H3.2, but was substantially detected with the replacement histone H3.3 variant. A mutational analysis revealed that the H3.3 Ile89 residue, corresponding to the H3.1 Val89 residue, is responsible for the tNASP-mediated nucleosome assembly with H3.3. A histone deposition assay showed that the H3.3-H4 complex is more efficiently deposited onto DNA by tNASP than the H3.1-H4 complex. These results provide evidence that tNASP is ubiquitously produced in various types of human tissues, and promotes in vitro nucleosome assembly with H3 variant specificity.
    Biochemistry 01/2015; · 3.38 Impact Factor
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    ABSTRACT: The histone H2A/H2B dimer is a component of nucleosome core particles (NCPs). The structure of the dimer at the atomic level has not yet been revealed. A possible reason for this is that the dimer has three intrinsically disordered tail regions: the N- and C-termini of H2A and the N-terminus of H2B. To investigate the role of the tail regions of the H2A/H2B dimer structure, we characterized behaviors of the H2A/H2B mutant dimers, in which these functionally important disordered regions were depleted, using mass spectrometry (MS). After verifying that the acetylation of Lys residues in the tail regions had little effect on the gas-phase conformations of the wild-type dimer, we prepared two histone H2A/H2B dimer mutants: an H2A/H2B dimer depleted of both N-termini (dN-H2A/dN-H2B) and a dimer with the N- and C-termini of H2A and the N-terminus of H2B depleted (dNC-H2A/dN-H2B). We analyzed these mutants using IM-MS and hydrogen/deuterium exchange mass spectrometry (HDX-MS). With IM-MS, reduced structural diversity was observed for each of the tail-truncated H2A/H2B mutants. In addition, global HDX-MS proved that the dimer mutant dNC-H2A/dN-H2B was susceptible to deuteration, suggesting that its structure in solution was somewhat loosened. A partial relaxation of the mutant's structure was demonstrated also by IM-MS. In this study, we characterized the relationship between the tail lengths and the conformations of the H2A/H2B dimer in solution and gas phases, and demonstrated using mass spectrometry that disordered tail regions play an important role in stabilizing the conformation of the core region of the dimer in both phases.
    Analytical chemistry. 01/2015;
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    ABSTRACT: FANCD2 is a product of one of the genes associated with Fanconi anemia (FA), a rare recessive disease characterized by bone marrow failure, skeletal malformations, developmental defects, and cancer predisposition. FANCD2 forms a complex with FANCI (ID complex) and is monoubiquitinated, which facilitates the downstream interstrand crosslink (ICL) repair steps, such as ICL unhooking and nucleolytic end resection. In the present study, we focused on the chicken FANCD2 (cFANCD2) mutant harboring the Leu234 to Arg (L234R) substitution. cFANCD2 L234R corresponds to the human FANCD2 L231R mutation identified in an FA patient. We found that cFANCD2 L234R did not complement the defective ICL repair in FANCD2-/- DT40 cells. Purified cFANCD2 L234R did not bind to chicken FANCI, and its monoubiquitination was significantly deficient, probably due to the abnormal ID complex formation. In addition, the histone chaperone activity of cFANCD2 L234R was also defective. These findings may explain some aspects of Fanconi anemia pathogenesis by a FANCD2 missense mutation.
    PLoS ONE 12/2014; 9(12):e114752. · 3.53 Impact Factor
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    ABSTRACT: The centromere-specific histone H3 variant, CENP-A, is overexpressed in particular aggressive cancer cells, where it can be mislocalized ectopically in the form of heterotypic nucleosomes containing H3.3. In the present study, we report the crystal structure of the heterotypic CENP-A/H3.3 particle and reveal its "hybrid structure", in which the physical characteristics of CENP-A and H3.3 are conserved independently within the same particle. The CENP-A/H3.3 nucleosome forms an unexpectedly stable structure as compared to the CENP-A nucleosome, and allows the binding of the essential centromeric protein, CENP-C, which is ectopically mislocalized in the chromosomes of CENP-A overexpressing cells.
    Scientific Reports 11/2014; 4:7115. · 5.08 Impact Factor
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    ABSTRACT: The DNA interstrand crosslink (ICL) is an extremely deleterious DNA lesion that covalently crosslinks complementary strands and prevents the strand-separation reaction. In higher eukaryotes, the Fanconi anemia proteins, FANCI and FANCD2, form a heterodimer and play essential roles in ICL repair. Human FANCI and FANCD2 are large proteins with molecular masses of 149 kDa and 164 kDa, respectively, and were reportedly purified using a baculovirus expression system with insect cells. We have established a novel expression and purification procedure for human FANCD2 and FANCI, using Escherichia coli cells. The human FANCD2 and FANCI proteins purified by this bacterial expression method formed a stable heterodimer, and exhibited DNA binding and histone chaperone activities, as previously reported for the proteins purified by the baculovirus system. Therefore, these purification methods for human FANCI and FANCD2 provide novel procedures to facilitate structural and biochemical studies of human FANCI and FANCD2.
    Protein Expression and Purification 11/2014; · 1.43 Impact Factor
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    ABSTRACT: Heterochromatin protein 1 (HP1) is an evolutionar-ily conserved chromosomal protein that binds to lysine 9-methylated histone H3 (H3K9me), a hall-mark of heterochromatin. Although HP1 phospho-rylation has been described in several organisms, the biological implications of this modification re-main largely elusive. Here we show that HP1's phos-phorylation has a critical effect on its nucleosome binding properties. By in vitro phosphorylation as-says and conventional chromatography, we demon-strated that casein kinase II (CK2) is the kinase primarily responsible for phosphorylating the N-terminus of human HP1␣. Pull-down assays using in vitro-reconstituted nucleosomes showed that un-modified HP1␣ bound H3K9-methylated and H3K9-unmethylated nucleosomes with comparable affin-ity, whereas CK2-phosphorylated HP1␣ showed a high specificity for H3K9me3-modified nucleosomes. Electrophoretic mobility shift assays showed that CK2-mediated phosphorylation diminished HP1␣'s intrinsic DNA binding, which contributed to its H3K9me-independent nucleosome binding. CK2-mediated phosphorylation had a similar effect on the nucleosome-binding specificity of fly HP1a and S. pombe Swi6. These results suggested that HP1 phos-phorylation has an evolutionarily conserved role in HP1's recognition of H3K9me-marked nucleosomes.
    Nucleic Acids Research 10/2014; · 8.81 Impact Factor
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    ABSTRACT: To optimize live cell fluorescence imaging, the choice of fluorescent substrate is a critical factor. Although genetically encoded fluorescent proteins have been used widely, chemical fluorescent dyes are still useful when conjugated to proteins or ligands. However, little information is available for the suitability of different fluorescent dyes for live imaging. We here systematically analyzed the property of a number of commercial fluorescent dyes when conjugated with antigen-binding (Fab) fragments directed against specific histone modifications, in particular, phosphorylated H3S28 (H3S28ph) and acetylated H3K9 (H3K9ac). These Fab fragments were conjugated with a fluorescent dye and loaded into living HeLa cells. H3S28ph-specific Fab fragments were expected to be enriched in condensed chromosomes, as H3S28 is phosphorylated during mitosis. However, the degree of Fab fragment enrichment on mitotic chromosomes varied depending on the conjugated dye. In general, green fluorescent dyes showed higher enrichment, compared to red and far-red fluorescent dyes, even when dye∶protein conjugation ratios were similar. These differences are partly explained by an altered affinity of Fab fragment after dye-conjugation; some dyes have less effect on the affinity, while others can affect it more. Moreover, red and far-red fluorescent dyes tended to form aggregates in the cytoplasm. Similar results were observed when H3K9ac-specific Fab fragments were used, suggesting that the properties of each dye affect different Fab fragments similarly. According to our analysis, conjugation with green fluorescent dyes, like Alexa Fluor 488 and Dylight 488, has the least effect on Fab affinity and is the best for live cell imaging, although these dyes are less photostable than red fluorescent dyes. When multicolor imaging is required, we recommend the following dye combinations for optimal results: Alexa Fluor 488 (green), Cy3 (red), and Cy5 or CF640 (far-red).
    PLoS ONE 09/2014; 9(9):e106271. · 3.53 Impact Factor
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    ABSTRACT: Nucleosomes are extremely stable histone-DNA complexes that form the building blocks of chromatin, which accommodates genomic DNA within the nucleus. The dynamic properties of chromatin play essential roles in regulating genomic DNA functions, such as DNA replication, recombination, repair, and transcription. Histones are the protein components of nucleosomes, and their diverse modifications and variants increase the versatility of nucleosome structures and their dynamics in chromatin. Therefore, a technique to evaluate the physical properties of nucleosomes would facilitate functional studies of the various nucleosomes. In this report, we describe a convenient assay for evaluating the thermal stability of nucleosomes in vitro.
    Methods 09/2014; · 3.22 Impact Factor
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    ABSTRACT: Nucleosomes containing a human histone variant, H2A.B, in an aqueous solution were analyzed by small-angle neutron scattering utilizing a contrast variation technique. Comparisons with the canonical H2A nucleosome structure revealed that the DNA termini of the H2A.B nucleosome are detached from the histone core surface, and flexibly expanded toward the solvent. In contrast, the histone tails are compacted in H2A.B nucleosomes compared to those in canonical H2A nucleosomes, suggesting that they bind to the surface of the histone core and/or DNA. Therefore, the histone tail dynamics may function to regulate the flexibility of the DNA termini in the nucleosomes.
    Biophysical journal. 05/2014; 106(10):2206-13.
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    ABSTRACT: Homologous recombination plays essential roles in mitotic DNA double strand break (DSB) repair and meiotic genetic recombination. In eukaryotes, RAD51 promotes the central homologous-pairing step during homologous recombination, but is not sufficient to overcome the reaction barrier imposed by nucleosomes. RAD54, a member of the ATP-dependent nucleosome remodeling factor family, is required to promote the RAD51-mediated homologous pairing in nucleosomal DNA. In higher eukaryotes, most nucleosomes form higher-ordered chromatin containing the linker histone H1. However, the mechanism by which RAD51/RAD54-mediated homologous pairing occurs in higher-ordered chromatin has not been elucidated. In this study, we found that a histone chaperone, Nap1, accumulates on DSB sites in human cells, and DSB repair is substantially decreased in Nap1-knockdown cells. We determined that Nap1 binds to RAD54, enhances the RAD54-mediated nucleosome remodeling by evicting histone H1, and eventually stimulates the RAD51-mediated homologous pairing in higher-ordered chromatin containing histone H1.
    Scientific Reports 05/2014; 4:4863. · 5.08 Impact Factor
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    ABSTRACT: The Fanconi anemia (FA) pathway is critically involved in the maintenance of hematopoietic stem cells and the suppression of carcinogenesis. A key FA protein, FANCD2, is monoubiquitinated and accumulates in chromatin in response to DNA interstrand crosslinks (ICLs), where it coordinates DNA repair through mechanisms that are still poorly understood. Here, we report that CtIP protein directly interacts with FANCD2. A region spanning amino acids 166 to 273 of CtIP and monoubiquitination of FANCD2 are both essential for the FANCD2-CtIP interaction and mitomycin C (MMC)-induced CtIP foci. Remarkably, both FANCD2 and CtIP are critical for MMC-induced RPA2 hyperphosphorylation, an event that accompanies end resection of double-strand breaks. Collectively, our results reveal a role of monoubiquitinated FANCD2 in end resection that depends on its binding to CtIP during ICL repair.
    Cell Reports 04/2014; · 7.21 Impact Factor
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    ABSTRACT: The human histone H2B variant TSH2B is highly expressed in testis and may function in the chromatin transition during spermatogenesis. In the present study, the crystal structure of the human testis-specific nucleosome containing TSH2B was determined at 2.8 Å resolution. A local structural difference between TSH2B and canonical H2B in nucleosomes was detected around the TSH2B-specific amino-acid residue Ser85. The TSH2B Ser85 residue does not interact with H4 in the nucleosome, but in the canonical nucleosome the H2B Asn84 residue (corresponding to the TSH2B Ser85 residue) forms water-mediated hydrogen bonds with the H4 Arg78 residue. In contrast, the other TSH2B-specific amino-acid residues did not induce any significant local structural changes in the TSH2B nucleosome. These findings may provide important information for understanding how testis-specific histone variants form nucleosomes during spermatogenesis.
    Acta Crystallographica Section F. 04/2014; 70(4).
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    ABSTRACT: Centromeres are essential for ensuring proper chromosome segregation in eukaryotes. Their definition relies on the presence of a centromere-specific H3 histone variant CenH3, known as CENP-A in mammals. Its overexpression in aggressive cancers raises questions concerning its effect on chromatin dynamics and contribution to tumorigenesis. We find that CenH3 overexpression in human cells leads to ectopic enrichment at sites of active histone turnover involving a heterotypic tetramer containing CenH3-H4 with H3.3-H4. Ectopic localization of this particle depends on the H3.3 chaperone DAXX rather than the dedicated CenH3 chaperone HJURP. This aberrant nucleosome occludes CTCF binding and has a minor effect on gene expression. Cells overexpressing CenH3 are more tolerant of DNA damage. Both the survival advantage and CTCF occlusion in these cells are dependent on DAXX. Our findings illustrate how changes in histone variant levels can disrupt chromatin dynamics and suggests a possible mechanism for cell resistance to anticancer treatments.
    Molecular cell 02/2014; · 14.46 Impact Factor
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    ABSTRACT: Actin and actin-related proteins (Arps), which are members of the actin family, are essential components of many of these remodeling complexes. Actin, Arp4, Arp5, and Arp8 are found to be evolutionarily conserved components of the INO80 chromatin remodeling complex, which is involved in transcriptional regulation, DNA replication, and DNA repair. A recent report showed that Arp8 forms a module in the INO80 complex and this module can directly capture a nucleosome. In the present study, we showed that recombinant human Arp8 binds to DNAs, and preferentially binds to single-stranded DNA. Analysis of the binding of adenine nucleotides to Arp8 mutants suggested that the ATP-binding pocket, located in the evolutionarily conserved actin fold, plays a regulatory role in the binding of Arp8 to DNA. To determine the cellular function of Arp8, we derived tetracycline-inducible Arp8 knockout cells from a cultured human cell line. Analysis of results obtained after treating these cells with aphidicolin and camptothecin revealed that Arp8 is involved in DNA repair. Together with the previous observation that Arp8, but not γ-H2AX, is indispensable for recruiting INO80 complex to DSB in human, results of our study suggest an individual role for Arp8 in DNA repair.
    PLoS ONE 01/2014; 9(10):e108354. · 3.53 Impact Factor
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    ABSTRACT: During meiosis, homologous recombination (HR) is essential to repair programmed DNA double-strand breaks (DSBs), and a dedicated protein machinery ensures that the homologous chromosome is favored over the nearby sister chromatid as a repair template. The HOMOLOGOUS-PAIRING PROTEIN2/MEIOTIC NUCLEAR DIVISION PROTEIN1 (HOP2/MND1) protein complex has been identified as a crucial factor of meiotic HR in Arabidopsis thaliana, since loss of either MND1 or HOP2 results in failure of DNA repair. We isolated two mutant alleles of HOP2 (hop2-2 and hop2-3) that retained the capacity to repair meiotic DSBs via the sister chromatid but failed to use the homologous chromosome. We show that in these alleles, the recombinases RADIATION SENSITIVE51 (RAD51) and DISRUPTED MEIOTIC cDNA1 (DMC1) are loaded, but only the intersister DNA repair pathway is activated. The hop2-2 phenotype is correlated with a decrease in HOP2/MND1 complex abundance. In hop2-3, a truncated HOP2 protein is produced that retains its ability to bind to DMC1 and DNA but forms less stable complexes with MND1 and fails to efficiently stimulate DMC1-driven D-loop formation. Genetic analyses demonstrated that in the absence of DMC1, HOP2/MND1 is dispensable for RAD51-mediated intersister DNA repair, while in the presence of DMC1, a minimal amount of functional HOP2/MND1 is essential to drive intersister DNA repair.
    The Plant Cell 12/2013; · 9.58 Impact Factor
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    ABSTRACT: Human histone H2A.B (formerly H2A.Bbd), a non-allelic H2A variant, exchanges rapidly as compared to canonical H2A, and preferentially associates with actively transcribed genes. We found that H2A.B transiently accumulated at DNA replication and repair foci in living cells. To explore the biochemical function of H2A.B, we performed nucleosome reconstitution analyses using various lengths of DNA. Two types of H2A.B nucleosomes, octasome and hexasome, were formed with 116, 124, or 130 base pairs (bp) of DNA, and only the octasome was formed with 136 or 146 bp DNA. In contrast, only hexasome formation was observed by canonical H2A with 116 or 124 bp DNA. A small-angle X-ray scattering analysis revealed that the H2A.B octasome is more extended, due to the flexible detachment of the DNA regions at the entry/exit sites from the histone surface. These results suggested that H2A.B rapidly and transiently forms nucleosomes with short DNA segments during chromatin reorganization.
    Scientific Reports 12/2013; 3:3510. · 5.08 Impact Factor
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    ABSTRACT: The histone H2A.Z variant is widely conserved among eukaryotes. Two isoforms, H2A.Z.1 and H2A.Z.2, have been identified in vertebrates and may have distinct functions in cell growth and gene expression. However, no structural differences between H2A.Z.1 and H2A.Z.2 have been reported. In the present study, the crystal structures of nucleosomes containing human H2A.Z.1 and H2A.Z.2 were determined. The structures of the L1 loop regions were found to clearly differ between H2A.Z.1 and H2A.Z.2, although their amino-acid sequences in this region are identical. This structural polymorphism may have been induced by a substitution that evolutionally occurred at the position of amino acid 38 and by the flexible nature of the L1 loops of H2A.Z.1 and H2A.Z.2. It was also found that in living cells nucleosomal H2A.Z.1 exchanges more rapidly than H2A.Z.2. A mutational analysis revealed that the amino-acid difference at position 38 is at least partially responsible for the distinctive dynamics of H2A.Z.1 and H2A.Z.2. These findings provide important new information for understanding the differences in the regulation and functions of H2A.Z.1 and H2A.Z.2 in cells.
    Acta Crystallographica Section D Biological Crystallography 12/2013; 69(Pt 12):2431-9. · 7.23 Impact Factor
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    ABSTRACT: BRCA1, BRCA2 and PALB2 are key players in cellular tolerance to chemotherapeutic agents including camptothecin, cisplatin and poly[ADP ribose]polymerase inhibitor. The N-terminal segment of BRCA2 interacts with PALB2, thus contributing to the formation of the BRCA1-PALB2-BRCA2 complex. To understand the role played by BRCA2 in this complex, we deleted its N-terminal segment and generated BRCA2N mutant cells. Although previous studies have suggested that BRCA1-PALB2 plays a role in the recruitment of BRCA2 to DNA-damage sites, BRCA2N mutant cells displayed a considerably milder phenotype than did BRCA2-/- null-deficient cells. We hypothesized that the DNA-binding domain of BRCA2 might compensate for a defect in BRCA2N that prevented stable interaction with PALB2. To test this hypothesis, we disrupted the DNA-binding domain of BRCA2 in wild-type and BRCA2N cells. Remarkably, although the resulting BRCA2DBD cells displayed a moderate phenotype, the BRCA2N+DBD cells displayed a very severe phenotype, as did the BRCA2-/- cells, suggesting that the N-terminal segment and the DNA-binding domain play a substantially overlapping role in the functionality of BRCA2. We also showed that the formation of both the BRCA1-PALB2-BRCA2 complex and the DNA-binding domain is required for efficient recruitment of BRCA2 to DNA-damage sites. Our study revealed the essential role played by both the BRCA1-PALB2-BRCA2 complex and the DNA-binding domain in the functionality of BRCA2, as each can compensate for the other in the recruitment of BRCA2 to DNA-damage sites. This knowledge adds to our ability to accurately predict the efficacy of anti-malignant therapies for patients carrying mutations in the BRCA2 gene.
    Cancer Research 11/2013; · 9.28 Impact Factor
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    ABSTRACT: The centromere is a specific genomic region upon which the kinetochore is formed to attach to spindle microtubules for faithful chromosome segregation. To distinguish this chromosomal region from other genomic loci, the centromere contains a specific chromatin structure including specialized nucleosomes containing the histone H3 variant CENP-A. In addition to CENP-A nucleosomes, we have found that centromeres contain a nucleosome-like structure comprised of the histone-fold CENP-T-W-S-X complex. However, it is unclear how the CENP-T-W-S-X complex associates with centromere chromatin. Here, we demonstrate that the CENP-T-W-S-X complex binds preferentially to ∼100 bp of linker DNA rather than nucleosome-bound DNA. In addition, we find that the CENP-T-W-S-X complex primarily binds to DNA as a (CENP-T-W-S-X)2 structure. Interestingly, in contrast to canonical nucleosomes that negatively supercoil DNA, the CENP-T-W-S-X complex induces positive DNA supercoils. We found that the DNA-binding regions in CENP-T or CENP-W, but not CENP-S or CENP-X, are required for this positive supercoiling activity and the kinetochore targeting of the CENP-T-W-S-X complex. In summary, our work reveals the structural features and properties of the CENP-T-W-S-X complex for its localization to centromeres.
    Nucleic Acids Research 11/2013; · 8.81 Impact Factor
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    ABSTRACT: Telomeric DNAs consist of tandem repeats of G-clusters such as TTAGGG and TG1-3, which are the human and yeast repeat sequences, respectively. In the yeast Saccharomyces cerevisiae, the telomeric repeats are non-nucleosomal, whereas in humans, they are organized in tightly packaged nucleosomes. However, previous in vitro studies revealed that the binding affinities of human and yeast telomeric repeat sequences to histone octamers in vitro were similar, which is apparently inconsistent with the differences in the human and yeast telomeric chromatin structures. To further investigate the relationship between telomeric sequences and chromatin structure, we examined the effect of telomeric repeats on the formation of positioned nucleosomes in vivo by indirect end-label mapping, primer extension mapping and nucleosome repeat analyses, using a defined minichromosome in yeast cells. We found that the human and yeast telomeric repeat sequences both disfavour nucleosome assembly and alter nucleosome positioning in the yeast minichromosome. We further demonstrated that the G-clusters in the telomeric repeats are required for the nucleosome-disfavouring properties. Thus, our results suggest that this inherent structural feature of the telomeric repeat sequences is involved in the functional dynamics of the telomeric chromatin structure.
    Nucleic Acids Research 10/2013; · 8.81 Impact Factor

Publication Stats

2k Citations
775.97 Total Impact Points

Institutions

  • 2005–2014
    • Waseda University
      • • Graduate School of Advanced Science and Engineering
      • • Consolidated Research Institute for Advanced Science and Medical Care
      • • Department of Electrical Engineering and Bioscience
      Edo, Tōkyō, Japan
  • 2011–2013
    • Osaka University
      • Graduate School of Frontier Biosciences
      Suika, Ōsaka, Japan
    • Nihon University
      • Department of Applied Biological Science
      Edo, Tōkyō, Japan
  • 2002–2012
    • Kyoto University
      • Radiation Biology Center
      Kyoto, Kyoto-fu, Japan
  • 2004–2010
    • Yokohama City University
      • Graduate School of Nanobioscience
      Yokohama-shi, Kanagawa-ken, Japan
  • 2008
    • French National Centre for Scientific Research
      Lutetia Parisorum, Île-de-France, France
  • 2006–2008
    • Kyushu University
      • Faculty of Pharmaceutical Sciences
      Fukuoka-shi, Fukuoka-ken, Japan
  • 1999–2008
    • RIKEN
      • Laboratory for Cell Signaling
      Вако, Saitama, Japan
  • 2003
    • The University of Tokyo
      Tōkyō, Japan
  • 2001
    • Japan Science and Technology Agency (JST)
      Edo, Tōkyō, Japan