Details of the Researcher

PHOTO

Narie Sasaki
Section
Center for Diversity, Equity & Inclusion
Job title
Professor

Research History 16

  • 2026/04 - Present
    Yokohama National University　Center for Intersectional Innovations, Diversity Strategy Promotion Headquarters　Director/Professor/Special Adviser to the President

  • 2025/04 - Present
    Tohoku University　Center for Diversity, Equity, and Inclusion　Professor

  • 2025/07 - 2026/03
    Yokohama National University　Organization for Diversity Strategy

  • 2024/04 - 2025/06
    Yokohama National University　Diversity Strategy Promotion Headquarters　Visiting Professor

  • 2024/04 - 2025/03
    The University of Tokyo　Graduate School of Science Department of Biological Sciences　Project Associate Professor

  • 2022/04 - 2024/03
    Ochanomizu University　Institute for Gendered innovations

  • 2019/06 - 2022/03
    Ochanomizu University

  • 2010/04 - 2022/03
    Nagoya University

  • 2007/10 - 2010/03
    Nagoya University

  • 2007/04 - 2007/08
    Nagoya University

  • 2004/10 - 2007/03
    Ochanomizu University

  • 2004/05 - 2004/09
    ルイパスツール大学　研究員(フランス政府給費留学生)

  • 2002/10 - 2004/03
    Ochanomizu University　Faculty of Science Division of Biology

  • 2000/01 - 2002/09
    Japan Society for the Promotion of Science

  • 1999/04 - 1999/12
    Ochanomizu University　Faculty of Science

  • 1998/04 - 1999/03
    The University of Tokyo　Graduate School of Science

Show all Show first 5

Education 3

  • The University of Tokyo　Graduate School of Science Doctoral Program

    1995/04 - 1998/03

  • The University of Tokyo　Graduate School of Science

    1993/04 - 1995/03

  • Ochanomizu University　Faculty of Science　Division of Biology

    1989/04 - 1993/03

Committee Memberships 15

  • 塩竈市　しおがま男女共同参画推進審議会

    2026/04 - Present

  • 国立研究開発法人日本医療研究開発機構　科学技術調査員

    2024/08 - Present

  • 日本ロレアルWomen’s Empowerment Advisory Board

    2023 - Present

  • 日本性差医学・医療学会　理事

    2023/01 - Present

  • 一般社団法人 デジタル人材共創連盟　理事

    2022/10 - Present

  • 内閣府　男女共同参画専門調査会 計画実行・監視専門調査会

    2021/04 - Present

  • 公益財団法人日本メンデル協会 評議員

    2017/06 - Present

  • 日本学術会議　連携会員

    2014 - Present

  • 内閣府　男女共同参画専門調査会 第６次基本計画策定専門調査会

    2024/12 - 2026/03

  • 経済産業省　産業構造審議会 商務流通情報分科会 バイオ小委員会 バイオものづくり革命推進ワーキンググループ

    2023 - 2024

  • 経済産業省　産業構造審議会産業技術環境分科会 研究開発・イノベーション小委員会委員

    2018/11 - 2022/12

  • 経済産業省　デジタル関連部活支援の在り方に関する検討会

    2021/09 - 2022/03

  • 日本植物形態学会　広報委員長

    2018 - 2019

  • 日本植物生理学会　幹事

    2013 - 2014

  • 日本植物学会 男女共同参画委員

    2010 - 2014

Show all ︎Show first 5

Professional Memberships 4

  • 日本植物形態学会

  • 日本性差医学・医療学会

  • 日本ミトコンドリア学会

  • 日本植物学会

Research Interests 4

  • Gendered Innnovations

  • Maternal inheritance

  • Mitochondrial DNA

  • Mitochondrial nucleoid

Research Areas 3

  • Life sciences / Morphology, anatomy /

  • Life sciences / Molecular biology /

  • Life sciences / Cell biology /

Awards 4

  1. 保井コノ賞

    2016/02　お茶の水女子大学

  2. 平瀬賞

    2004/09　日本植物形態学会

  3. 保井・黒田奨学基金

    2003/10　お茶の水女子大学

  4. 湯浅年子記念基金特別研究員奨励賞

    2002/10　お茶の水女子大学

Papers 54

  1. Gendered Innovations in Health and Medicine Invited

    Narie Sasaki

    Gender Studies　28　61-71　2026/03

  2. The evolving landscape of gender equality in Japanese higher education, research, and innovation Peer-reviewed

    Miyoko O. Watanabe, Narie Sasaki

    Humanities and Social Sciences Communications　13　(1)　2026/01/28

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1057/s41599-026-06516-5 　

    eISSN： 2662-9992

    More details Close

    Abstract Japan has been identified as the nation where women’s participation is least advanced. This article addresses the central problem of women’s persistent underrepresentation in higher education and research in Japan. The research questions are: (1) How have government policies influenced universities’ actions? (2) What impacts can be observed from measures such as female quotas? (3) What lessons can Japan’s case provide in an international context? The underrepresentation of women in universities, particularly in science and engineering, is a significant issue. The analysis is grounded in theories of diversity and innovation. Methodologically, the study relies on document analysis of government plans, statistical data, and case studies of universities. Findings suggest that while policies such as the Basic Plans have shaped institutional practices, their effectiveness remains uneven. The article shows that Japan’s evolving approach highlights both the potential and the limitations of state-driven gender equality policies. Numerous universities have adopted a policy of exclusively recruiting female faculty members, while student admissions examinations are being aggressively opened more to women. These developments are in alignment with the government’s policy plans, suggesting that government-led initiatives are beginning to yield tangible results. Underway initiatives are closely related to the promotion of gendered innovations with the objective of enhancing scientific progress, and are recently promoted in Japan. It is anticipated that the consequences will disseminate throughout society. The cornerstone of gender equality is the eradication of discrimination within society. However, it is insufficient to effect societal change. This article elucidates the reasons why tackling discrimination alone will not achieve the ambitions of the changes actually occurring. The benefits of diversity are not only enjoyed by certain people. Gender equality benefits all the people in the society. With this understanding, there has been notable progress towards gender equality in recent years, especially in the field of higher education institutions.

  3. 生命科学分野におけるジェンダード・イノベーションとその科学技術政策への展開 Invited

    佐々木成江

    科学技術社会論研究　24　2026/01

  4. Human RCC1L is involved in the maintenance of mitochondrial nucleoids and mtDNA Peer-reviewed

    Emi Matsumoto, Taeko Sasaki, Tetsuya Higashiyama, Narie Sasaki

    Scientific Reports　15　(1)　2025/04/21

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41598-025-98397-y 　

    eISSN： 2045-2322

  5. Rapid Selective Proliferation of Mitochondria during Zygote Maturation in the Uniparental Inheritance of <i>Physarum polycephalum</i> Peer-reviewed

    Naoki Urakawa, Kakishi Uno, Yoshikatsu Sato, Tetsuya Higashiyama, Narie Sasaki

    CYTOLOGIA　87　(2)　163-168　2022/06/25

    Publisher: International Society of Cytology

    DOI： 10.1508/cytologia.87.163 　

    ISSN： 0011-4545

    eISSN： 1348-7019

  6. Live imaging-based assay for visualising species-specific interactions in gamete adhesion molecules. International-journal Peer-reviewed

    Kohdai P Nakajima, Clari Valansi, Daisuke Kurihara, Narie Sasaki, Benjamin Podbilewicz, Tetsuya Higashiyama

    Scientific reports　12　(1)　9609-9609　2022/06/10

    DOI： 10.1038/s41598-022-13547-w 　

    More details Close

    Successful gamete fusion requires species-specific membrane adhesion. However, the interaction of adhesion molecules in gametes is difficult to study in real time through low-throughput microscopic observation. Therefore, we developed a live imaging-based adhesion molecule (LIAM) assay to study gamete adhesion molecule interactions in cultured cells. First, we modified a fusion assay previously established for fusogens introduced into cultured cells, and confirmed that our live imaging technique could visualise cell-cell fusion in the modified fusion assay. Next, instead of fusogen, we introduced adhesion molecules including a mammalian gamete adhesion molecule pair, IZUMO1 and JUNO, and detected their temporal accumulation at the contact interfaces of adjacent cells. Accumulated IZUMO1 or JUNO was partly translocated to the opposite cells as discrete spots; the mutation in amino acids required for their interaction impaired accumulation and translocation. By using the LIAM assay, we investigated the species specificity of IZUMO1 and JUNO of mouse, human, hamster, and pig in all combinations. IZUMO1 and JUNO accumulation and translocation were observed in conspecific, and some interspecific, combinations, suggesting potentially interchangeable combinations of IZUMO1 and JUNO from different species.

  7. Semi-in vitro detection of Mg2+-dependent DNase that specifically digest mitochondrial nucleoids in the zygote of Physarum polycephalum. International-journal Peer-reviewed

    Naoki Urakawa, Satoru Nakamura, Mariko Kishimoto, Yohsuke Moriyama, Shigeyuki Kawano, Tetsuya Higashiyama, Narie Sasaki

    Scientific reports　12　(1)　2995-2995　2022/02/22

    DOI： 10.1038/s41598-022-06920-2 　

    More details Close

    The maternal/uniparental inheritance of mitochondria is controlled by the selective elimination of paternal/uniparental mitochondria and digestion of their mitochondrial DNA (mtDNA). In isogamy, the selective digestion of mtDNA in uniparental mitochondria is initiated after mating and is completed prior to the elimination of mitochondria, but the molecular mechanism of the digestion of uniparental mtDNA remains unknown. In this study, we developed a semi-in vitro assay for DNase, wherein the digestion of mitochondrial nucleoids (mt-nucleoids) was microscopically observed using isolated mitochondria from Physarum polycephalum and the DNase involved in uniparental inheritance was characterized. When myxamoebae of AI35 and DP246 are crossed, mtDNA and mt-nucleoid from only the DP246 parent are digested. The digestion of mt-nucleoids was observed in zygotes 3 h after plating for mating. During the digestion of mt-nucleoids, mitochondrial membrane integrity was maintained. In the semi-in vitro assay, the digestion of mt-nucleoids was only observed in the presence of Mg2+ at pH 7.5-9.0. Moreover, such Mg2+-dependent DNase activity was specifically detected in mitochondria isolated from zygotes 3 h after plating for mating. Therefore, Mg2+-dependent DNase is potentially involved in uniparental inheritance. Our findings provide insights into the DNase involved in uniparental inheritance and its regulatory mechanism.

  8. Live imaging reveals the dynamics and regulation of mitochondrial nucleoids during the cell cycle in Fucci2-HeLa cells. International-journal Peer-reviewed

    Taeko Sasaki, Yoshikatsu Sato, Tetsuya Higashiyama, Narie Sasaki

    Scientific reports　7　(1)　11257-11257　2017/09/12

    DOI： 10.1038/s41598-017-10843-8 　

    More details Close

    Mitochondrial DNA (mtDNA) is organized in nucleoprotein complexes called mitochondrial nucleoids (mt-nucleoids), which are critical units of mtDNA replication and transmission. In humans, several hundreds of mt-nucleoids exist in a cell. However, how numerous mt-nucleoids are maintained during the cell cycle remains elusive, because cell cycle synchronization procedures affect mtDNA replication. Here, we analyzed regulation of the maintenance of mt-nucleoids in the cell cycle, using a fluorescent cell cycle indicator, Fucci2. Live imaging of mt-nucleoids with higher temporal resolution showed frequent attachment and detachment of mt-nucleoids throughout the cell cycle. TFAM, an mtDNA packaging protein, was involved in the regulation of this dynamic process, which was important for maintaining proper mt-nucleoid number. Both an increase in mt-nucleoid number and activation of mtDNA replication occurred during S phase. To increase mt-nucleoid number, mtDNA replication, but not nuclear DNA replication, was necessary. We propose that these dynamic and regulatory processes in the cell cycle maintain several hundred mt-nucleoids in proliferating cells.

  9. Crystal structure of human WBSCR16, an RCC1-like protein in mitochondria. International-journal Peer-reviewed

    Masako Koyama, Taeko Sasaki, Narie Sasaki, Yoshiyuki Matsuura

    Protein science : a publication of the Protein Society　26　(9)　1870-1877　2017/09

    DOI： 10.1002/pro.3210 　

    More details Close

    WBSCR16 (Williams-Beuren Syndrome Chromosomal Region 16) gene is located in a large deletion region of Williams-Beuren syndrome (WBS), which is a neurodevelopmental disorder. Although the relationship between WBSCR16 and WBS remains unclear, it has been reported that WBSCR16 is a member of a functional module that regulates mitochondrial 16S rRNA abundance and intra-mitochondrial translation. WBSCR16 has RCC1 (Regulator of Chromosome Condensation 1)-like amino acid sequence repeats but the function of WBSCR16 appears to be different from that of other RCC1 superfamily members. Here, we demonstrate that WBSCR16 localizes to mitochondria in HeLa cells, and report the crystal structure of WBSCR16 determined to 2.0 Å resolution using multi-wavelength anomalous diffraction. WBSCR16 adopts the seven-bladed β-propeller fold characteristic of RCC1-like proteins. A comparison of the WBSCR16 structure with that of RCC1 and other RCC1-like proteins reveals that, although many of the residues buried in the core of the β-propeller are highly conserved, the surface residues are poorly conserved and conformationally divergent.

  10. Key Structural Elements of Unsymmetrical Cyanine Dyes for Highly Sensitive Fluorescence Turn-On DNA Probes. International-journal Peer-reviewed

    Kakishi Uno, Taeko Sasaki, Nagisa Sugimoto, Hideto Ito, Taishi Nishihara, Shinya Hagihara, Tetsuya Higashiyama, Narie Sasaki, Yoshikatsu Sato, Kenichiro Itami

    Chemistry, an Asian journal　12　(2)　233-238　2017/01/17

    DOI： 10.1002/asia.201601430 　

    More details Close

    Unsymmetrical cyanine dyes, such as thiazole orange, are useful for the detection of nucleic acids with fluorescence because they dramatically enhance the fluorescence upon binding to nucleic acids. Herein, we synthesized a series of unsymmetrical cyanine dyes and evaluated their fluorescence properties. A systematic structure-property relationship study has revealed that the dialkylamino group at the 2-position of quinoline in a series of unsymmetrical cyanine dyes plays a critical role in the fluorescence enhancement. Four newly designed unsymmetrical cyanine dyes showed negligible intrinsic fluorescence in the free state and strong fluorescence upon binding to double-stranded DNA (dsDNA) with a quantum yield of 0.53 to 0.90, which is 2 to 3 times higher than previous unsymmetrical cyanine dyes. A detailed analysis of the fluorescence lifetime revealed that the dialkylamino group at the 2-position of quinoline suppressed nonradiative decay in favor of increased fluorescence quantum yield. Moreover, these newly developed dyes were able to stain the nucleus specifically in fixed HeLa cells examined by using a confocal laser-scanning microscope.

  11. The AMOR Arabinogalactan Sugar Chain Induces Pollen-Tube Competency to Respond to Ovular Guidance. International-journal Peer-reviewed

    Akane G Mizukami, Rie Inatsugi, Jiao Jiao, Toshihisa Kotake, Keiko Kuwata, Kento Ootani, Satohiro Okuda, Subramanian Sankaranarayanan, Yoshikatsu Sato, Daisuke Maruyama, Hiroaki Iwai, Estelle Garénaux, Chihiro Sato, Ken Kitajima, Yoichi Tsumuraya, Hitoshi Mori, Junichiro Yamaguchi, Kenichiro Itami, Narie Sasaki, Tetsuya Higashiyama

    Current biology : CB　26　(8)　1091-7　2016/04/25

    DOI： 10.1016/j.cub.2016.02.040 　

    More details Close

    Precise directional control of pollen-tube growth by pistil tissue is critical for successful fertilization of flowering plants [1-3]. Ovular attractant peptides, which are secreted from two synergid cells on the side of the egg cell, have been identified [4-6]. Emerging evidence suggests that the ovular directional cue is not sufficient for successful guidance but that competency control by the pistil is critical for the response of pollen tubes to the attraction signal [1, 3, 7]. However, the female molecule for this competency induction has not been reported. Here we report that ovular methyl-glucuronosyl arabinogalactan (AMOR) induces competency of the pollen tube to respond to ovular attractant LURE peptides in Torenia fournieri. We developed a method for assaying the response capability of a pollen tube by micromanipulating an ovule. Using this method, we showed that pollen tubes growing through a cut style acquired a response capability in the medium by receiving a sufficient amount of a factor derived from mature ovules of Torenia. This factor, named AMOR, was identified as an arabinogalactan polysaccharide, the terminal 4-O-methyl-glucuronosyl residue of which was necessary for its activity. Moreover, a chemically synthesized disaccharide, the β isomer of methyl-glucuronosyl galactose (4-Me-GlcA-β-(1→6)-Gal), showed AMOR activity. No specific sugar-chain structure of plant extracellular matrix has been identified as a bioactive molecule involved in intercellular communication. We suggest that the AMOR sugar chain in the ovary renders the pollen tube competent to the chemotropic response prior to final guidance by LURE peptides.

  12. The Physarum polycephalum Genome Reveals Extensive Use of Prokaryotic Two-Component and Metazoan-Type Tyrosine Kinase Signaling. International-journal Peer-reviewed

    Pauline Schaap, Israel Barrantes, Pat Minx, Narie Sasaki, Roger W Anderson, Marianne Bénard, Kyle K Biggar, Nicolas E Buchler, Ralf Bundschuh, Xiao Chen, Catrina Fronick, Lucinda Fulton, Georg Golderer, Niels Jahn, Volker Knoop, Laura F Landweber, Chrystelle Maric, Dennis Miller, Angelika A Noegel, Rob Peace, Gérard Pierron, Taeko Sasaki, Mareike Schallenberg-Rüdinger, Michael Schleicher, Reema Singh, Thomas Spaller, Kenneth B Storey, Takamasa Suzuki, Chad Tomlinson, John J Tyson, Wesley C Warren, Ernst R Werner, Gabriele Werner-Felmayer, Richard K Wilson, Thomas Winckler, Jonatha M Gott, Gernot Glöckner, Wolfgang Marwan

    Genome biology and evolution　8　(1)　109-25　2015/11/27

    DOI： 10.1093/gbe/evv237 　

    More details Close

    Physarum polycephalum is a well-studied microbial eukaryote with unique experimental attributes relative to other experimental model organisms. It has a sophisticated life cycle with several distinct stages including amoebal, flagellated, and plasmodial cells. It is unusual in switching between open and closed mitosis according to specific life-cycle stages. Here we present the analysis of the genome of this enigmatic and important model organism and compare it with closely related species. The genome is littered with simple and complex repeats and the coding regions are frequently interrupted by introns with a mean size of 100 bases. Complemented with extensive transcriptome data, we define approximately 31,000 gene loci, providing unexpected insights into early eukaryote evolution. We describe extensive use of histidine kinase-based two-component systems and tyrosine kinase signaling, the presence of bacterial and plant type photoreceptors (phytochromes, cryptochrome, and phototropin) and of plant-type pentatricopeptide repeat proteins, as well as metabolic pathways, and a cell cycle control system typically found in more complex eukaryotes. Our analysis characterizes P. polycephalum as a prototypical eukaryote with features attributed to the last common ancestor of Amorphea, that is, the Amoebozoa and Opisthokonts. Specifically, the presence of tyrosine kinases in Acanthamoeba and Physarum as representatives of two distantly related subdivisions of Amoebozoa argues against the later emergence of tyrosine kinase signaling in the opisthokont lineage and also against the acquisition by horizontal gene transfer.

  13. Environment-sensitive fluorescent probe: a benzophosphole oxide with an electron-donating substituent. International-journal Peer-reviewed

    Eriko Yamaguchi, Chenguang Wang, Aiko Fukazawa, Masayasu Taki, Yoshikatsu Sato, Taeko Sasaki, Minako Ueda, Narie Sasaki, Tetsuya Higashiyama, Shigehiro Yamaguchi

    Angewandte Chemie (International ed. in English)　54　(15)　4539-43　2015/04/07

    DOI： 10.1002/anie.201500229 　

    More details Close

    Electron-donating aryl groups were attached to electron-accepting benzophosphole skeletons. Among several derivatives thus prepared, one benzophosphole oxide was particularly interesting, as it retained high fluorescence quantum yields even in polar and protic solvents. This phosphole-based compound exhibited a drastic color change of its fluorescence spectrum as a function of the solvent polarity, while the absorption spectra remained virtually unchanged. Capitalizing on these features, this phosphole-based compound was used to stain adipocytes, in which the polarity of subcellular compartments could then be discriminated on the basis of the color change of the fluorescence emission.

  14. Dynamics of nucleoid structure regulated by mitochondrial fission contributes to cristae reformation and release of cytochrome c. International-journal Peer-reviewed

    Reiko Ban-Ishihara, Takaya Ishihara, Narie Sasaki, Katsuyoshi Mihara, Naotada Ishihara

    Proceedings of the National Academy of Sciences of the United States of America　110　(29)　11863-8　2013/07/16

    DOI： 10.1073/pnas.1301951110 　

    More details Close

    Mammalian cells typically contain thousands of copies of mitochondrial DNA assembled into hundreds of nucleoids. Here we analyzed the dynamic features of nucleoids in terms of mitochondrial membrane dynamics involving balanced fusion and fission. In mitochondrial fission GTPase dynamin-related protein (Drp1)-deficient cells, nucleoids were enlarged by their clustering within hyperfused mitochondria. In normal cells, mitochondrial fission often occurred adjacent to nucleoids, since localization of Mff and Drp1 is dependent on the nucleoids. Thus, mitochondrial fission adjacent to nucleoids should prevent their clustering by maintaining small and fragmented nucleoids. The enhanced clustering of nucleoids resulted in the formation of highly stacked cristae structures in enlarged bulb-like mitochondria (mito-bulbs). Enclosure of proapoptotic factor cytochrome c, but not of Smac/DIABLO, into the highly stacked cristae suppressed its release from mitochondria under apoptotic stimuli. In the absence of nucleoids, Drp1 deficiency failed to form mito-bulbs and to protect against apoptosis. Thus, mitochondrial dynamics by fission and fusion play a critical role in controlling mitochondrial nucleoid structures, contributing to cristae reformation and the proapoptotic status of mitochondria.

  15. Acquisition of LURE-binding activity at the pollen tube tip of Torenia fournieri. International-journal Peer-reviewed

    Satohiro Okuda, Takamasa Suzuki, Masahiro M Kanaoka, Hitoshi Mori, Narie Sasaki, Tetsuya Higashiyama

    Molecular plant　6　(4)　1074-90　2013/07

    DOI： 10.1093/mp/sst050 　

    More details Close

    Pollen tube guidance is controlled by multiple complex interactions with the female tissues. Here, we show that pollen tubes of Torenia fournieri are regulated by a stylar tissue in a length-dependent manner to receive and respond to attractant LURE peptides secreted from synergid cells. We developed an immunostaining method to visualize LURE peptides bound at the plasma membrane of the tip region of the pollen tube. Using this method, we found that LURE peptides bound specifically to pollen tubes growing through a cut style. The peptides also bound to pollen tubes growing through a shorter style, which were not competent to respond to these peptides. These observations suggested a possibility that acquisition of the LURE peptide reception ability and acquisition of full competency are separable processes. RNA-Seq suggested that the transcription profile of pollen tubes was affected by both the length of the style and the cultivation period, consistently with physiological changes in binding activity and LURE response ability. The database generated from de novo RNA-Seq of Torenia pollen tubes was shown to be useful to identify pollen tube proteins by mass spectrometry. Our studies provide insight and an effective platform for protein identification to understand pollen tube guidance.

  16. Identification and characterization of TcCRP1, a pollen tube attractant from Torenia concolor. International-journal Peer-reviewed

    Masahiro M Kanaoka, Nao Kawano, Yoshiyuki Matsubara, Daichi Susaki, Satohiro Okuda, Narie Sasaki, Tetsuya Higashiyama

    Annals of botany　108　(4)　739-47　2011/09

    DOI： 10.1093/aob/mcr111 　

    More details Close

    BACKGROUND AND AIMS: During sexual reproduction in higher angiosperms, the pollen tubes are directed to the ovules in the pistil to deliver sperm cells. This pollen tube attraction is highly species specific, and a group of small secreted proteins, TfCRPs, are necessary for this process in Torenia fournieri. METHODS: A candidate pollen tube attractant protein in Torenia concolor, a related species of T. fournieri, was isolated and the attractant abilities between them were compared. KEY RESULTS: TcCRP1, an orthologous gene of TfCRP1 from T. concolor, is expressed predominantly in the synergid cell. The gene product attracted pollen tubes in a concentration-dependent manner, but attracted fewer pollen tubes from the other species. CONCLUSIONS: The results indicated that this class of CRP proteins is a common pollen tube attractant in Torenia species. The sequence diversity of these proteins is important for species-specific pollen tube attraction.

  17. DNA packaging proteins Glom and Glom2 coordinately organize the mitochondrial nucleoid of Physarum polycephalum. International-journal Peer-reviewed

    Kie Itoh, Akiko Izumi, Toshiyuki Mori, Naoshi Dohmae, Ryoko Yui, Katsura Maeda-Sano, Yuki Shirai, Masahiro M Kanaoka, Tsuneyoshi Kuroiwa, Tetsuya Higashiyama, Mamoru Sugita, Kimiko Murakami-Murofushi, Shigeyuki Kawano, Narie Sasaki

    Mitochondrion　11　(4)　575-86　2011/07

    DOI： 10.1016/j.mito.2011.03.002 　

    More details Close

    Mitochondrial DNA (mtDNA) is generally packaged into the mitochondrial nucleoid (mt-nucleoid) by a high-mobility group (HMG) protein. Glom is an mtDNA-packaging HMG protein in Physarum polycephalum. Here we identified a new mtDNA-packaging protein, Glom2, which had a region homologous with yeast Mgm101. Glom2 could bind to an entire mtDNA and worked synergistically with Glom for condensation of mtDNA in vitro. Down-regulation of Glom2 enhanced the alteration of mt-nucleoid morphology and the loss of mtDNA induced by down-regulation of Glom, and impaired mRNA accumulation of some mtDNA-encoded genes. These data suggest that Glom2 may organize the mt-nucleoid coordinately with Glom.

  18. Novel sterol glucosyltransferase in the animal tissue and cultured cells: evidence that glucosylceramide as glucose donor. International-journal Peer-reviewed

    Hisako Akiyama, Narie Sasaki, Shuwa Hanazawa, Mari Gotoh, Susumu Kobayashi, Yoshio Hirabayashi, Kimiko Murakami-Murofushi

    Biochimica et biophysica acta　1811　(5)　314-22　2011/05

    DOI： 10.1016/j.bbalip.2011.02.005 　

    More details Close

    Cholesteryl glucoside (CG), a membrane glycolipid, regulates heat shock response. CG is rapidly induced by heat shock before the activation of heat shock transcription factor 1 (HSF1) and production of heat shock protein 70 (HSP70), and the addition of CG in turn induces HSF1 activation and HSP70 production in human fibroblasts; thus, a reasonable correlation is that CG functions as a crucial lipid mediator in stress responses in the animal. In this study, we focused on a CG-synthesizing enzyme, animal sterol glucosyltransferase, which has not yet been identified. In this study, we describe a novel type of animal sterol glucosyltransferase in hog stomach and human fibroblasts (TIG-3) detected by a sensitive assay with a fluorescence-labeled substrate. The cationic requirement, inhibitor resistance, and substrate specificity of animal sterol glucosyltransferase were studied. Interestingly, animal sterol glucosyltransferase did not use uridine diphosphate glucose (UDP-glucose) as an immediate glucose donor, as has been shown in plants and fungi. Among the glycolipids tested in vitro, glucosylceramide (GlcCer) was the most effective substrate for CG formation in animal tissues and cultured cells. Using chemically synthesized [U-((13))C]Glc-β-Cer as a glucose donor, we confirmed by mass spectrometry that [U-((13))C]CG was synthesized in hog stomach homogenate. These results suggest that animal sterol glucosyltransferase transfers glucose moiety from GlcCer to cholesterol. Additionally, using GM-95, a mutant B16 melanoma cell line that does not express ceramide glucosyltransferase, we showed that GlcCer is an essential substrate for animal sterol glucosyltransferase in the cell.

  19. Live-cell imaging reveals the dynamics of two sperm cells during double fertilization in Arabidopsis thaliana. International-journal Peer-reviewed

    Yuki Hamamura, Chieko Saito, Chie Awai, Daisuke Kurihara, Atsushi Miyawaki, Tsuyoshi Nakagawa, Masahiro M Kanaoka, Narie Sasaki, Akihiko Nakano, Frédéric Berger, Tetsuya Higashiyama

    Current biology : CB　21　(6)　497-502　2011/03/22

    DOI： 10.1016/j.cub.2011.02.013 　

    More details Close

    Flowering plants have evolved a unique reproductive process called double fertilization, whereby two dimorphic female gametes are fertilized by two immotile sperm cells conveyed by the pollen tube. The two sperm cells are arranged in tandem with a leading pollen tube nucleus to form the male germ unit and are placed under the same genetic controls. Genes controlling double fertilization have been identified, but whether each sperm cell is able to fertilize either female gamete is still unclear. The dynamics of individual sperm cells after their release in the female tissue remain largely unknown. In this study, we photolabeled individual isomorphic sperm cells before their release and analyzed their fate during double fertilization in Arabidopsis thaliana. We found that sperm delivery was composed of three steps. Sperm cells were projected together to the boundary between the two female gametes. After a long period of immobility, each sperm cell fused with either female gamete in no particular order, and no preference was observed for either female gamete. Our results suggest that the two sperm cells at the front and back of the male germ unit are functionally equivalent and suggest unexpected cell-cell communications required for sperm cells to coordinate double fertilization of the two female gametes.

  20. Isolation of Gametophytic Cells and Identification of Their Cell-Specific Markers in Torenia fournieri, T. concolor and Lindernia micrantha Peer-reviewed

    Nao Kawano, Daichi Susaki, Narie Sasaki, Tetsuya Higashiyama, Masahiro M. Kanaoka

    CYTOLOGIA　76　(2)　177-184　2011

    Publisher: International Society of Cytology

    DOI： 10.1508/cytologia.76.177 　

    ISSN： 0011-4545

    eISSN： 1348-7019

  21. Chemical visualization of an attractant peptide, LURE. Peer-reviewed

    Hiroaki Goto, Satohiro Okuda, Akane Mizukami, Hitoshi Mori, Narie Sasaki, Daisuke Kurihara, Tetsuya Higashiyama

    Plant & cell physiology　52　(1)　49-58　2011/01

    DOI： 10.1093/pcp/pcq191 　

    More details Close

    The pollen tube attractant peptide LUREs of Torenia fournieri are diffusible peptides that attract pollen tubes in vitro. Here, we report a method enabling the direct visualization of a LURE peptide without inhibiting its attraction activity by conjugating it with the Alexa Fluor 488 fluorescent dye. After purifying and refolding the recombinant LURE2 with a polyhistidine tag, its amino groups were targeted for conjugation with the Alexa Fluor dye. Labeling of LURE2 was confirmed by its fluorescence and mass spectrometry. In our in vitro assay using gelatin beads, Alexa Fluor 488-labeled LURE2 appeared to have the same activity as unlabeled LURE2. Using the labeled LURE2, the relationship between the spatiotemporal change of distribution and activity of LURE2 was examined. LURE2 attracted pollen tubes when embedded in gelatin beads, but hardly at all when in agarose beads. Direct visualization suggested that the significant difference between these conditions was the retention of LURE2 in the gelatin bead, which might delay diffusion of LURE2 from the bead. Direct visualization of LURE peptide may open the way to studying the spatiotemporal dynamics of LURE in pollen tube attraction.

  22. New protein p34 with an exonuclease motif localizes in the mitochondrial nucleoid periphery of Physarum polycephalum. Peer-reviewed

    Itoh, K, Izumi, A, Mori, T, Dohmae, N, Yui, R, Sano, K, Kanaoka, MM, Kuroiwa, H, Kuroiwa, T, Higashiyama, T, Murakami-Murofushi, K, Kawano, S, Sasaki, N

    Cytologia　74　401-407　2009/11

  23. MOV10 as a novel telomerase-associated protein Peer-reviewed

    Mariko Nakano, Yasutaka Kakiuchi, Yukiko Shimada, Mika Ohyama, Yasuko Ogiwara, Narie Sasaki-Higashiyama, Naoko Yano, Fumi Ikeda, Ei Yamada, Akihiro Iwamatsu, Kazuo Kobayashi, Kiyoto Nishiyama, Sohsuke Ichikawa, Kazuhiko Kaji, Toshinori Ide, Hiromu Murofushi, Kimiko Murakami-Murofushi

    Biochemical and Biophysical Research Communications　388　(2)　328-332　2009/10

    Publisher: Elsevier BV

    DOI： 10.1016/j.bbrc.2009.08.002 　

    ISSN： 0006-291X

  24. The Plasmodium HU homolog, which binds the plastid DNA sequence-independent manner, is essential for the parasite's survival. International-journal Peer-reviewed

    Narie Sasaki, Makoto Hirai, Katsura Maeda, Ryoko Yui, Kie Itoh, Syoko Namiki, Teppei Morita, Masayuki Hata, Kimiko Murakami-Murofushi, Hiroyuki Matsuoka, Kiyoshi Kita, Shigeharu Sato

    FEBS letters　583　(9)　1446-50　2009/05/06

    DOI： 10.1016/j.febslet.2009.03.071 　

    More details Close

    The nuclear genome of the human malaria parasite Plasmodium falciparum encodes a homolog of the bacterial HU protein (PfHU). In this study, we characterised PfHU's physiological function. PfHU, which is targeted exclusively to the parasite's plastid, bound its natural target--the plastid DNA--sequence-independently and complemented lack of HU in Escherichia coli. The HU gene could not be knocked-out from the genome of Plasmodium berghei, implying that HU is important for the parasite's survival. As the human cell lacks the HU homolog, PfHU is a potential target for drugs to control malaria.

  25. Defensin-like polypeptide LUREs are pollen tube attractants secreted from synergid cells. International-journal Peer-reviewed

    Satohiro Okuda, Hiroki Tsutsui, Keiko Shiina, Stefanie Sprunck, Hidenori Takeuchi, Ryoko Yui, Ryushiro D Kasahara, Yuki Hamamura, Akane Mizukami, Daichi Susaki, Nao Kawano, Takashi Sakakibara, Shoko Namiki, Kie Itoh, Kurataka Otsuka, Motomichi Matsuzaki, Hisayoshi Nozaki, Tsuneyoshi Kuroiwa, Akihiko Nakano, Masahiro M Kanaoka, Thomas Dresselhaus, Narie Sasaki, Tetsuya Higashiyama

    Nature　458　(7236)　357-61　2009/03/19

    DOI： 10.1038/nature07882 　

    More details Close

    For more than 140 years, pollen tube guidance in flowering plants has been thought to be mediated by chemoattractants derived from target ovules. However, there has been no convincing evidence of any particular molecule being the true attractant that actually controls the navigation of pollen tubes towards ovules. Emerging data indicate that two synergid cells on the side of the egg cell emit a diffusible, species-specific signal to attract the pollen tube at the last step of pollen tube guidance. Here we report that secreted, cysteine-rich polypeptides (CRPs) in a subgroup of defensin-like proteins are attractants derived from the synergid cells. We isolated synergid cells of Torenia fournieri, a unique plant with a protruding embryo sac, to identify transcripts encoding secreted proteins as candidate molecules for the chemoattractant(s). We found two CRPs, abundantly and predominantly expressed in the synergid cell, which are secreted to the surface of the egg apparatus. Moreover, they showed activity in vitro to attract competent pollen tubes of their own species and were named as LUREs. Injection of morpholino antisense oligomers against the LUREs impaired pollen tube attraction, supporting the finding that LUREs are the attractants derived from the synergid cells of T. fournieri.

  26. Visualiztion of nucleoids in living human cells using SYBR Green I.

    Ozawa, S, Sasaki, N

    Cytologia　74　365-366　2009

  27. Visualization of mitochondrial and apicoplast nucleoids in the human malaria parasite Plasmodium falciparum by SYBR Green I and PicoGreen staining. Peer-reviewed

    Sano-maeda, K, Sato, S, Ueda, T, Yui, R, Itoh, K, Hata, M, Nakano, A, Murakami-Murofushi, K, Sasaki, N

    CYTOLOGIA　74　(4)　449-455　2009

    Publisher: International Society of Cytology

    DOI： 10.1508/cytologia.74.449 　

    ISSN： 0011-4545

    eISSN： 1348-7019

  28. Early weaning induces anxiety and precocious myelination in the anterior part of the basolateral amygdala of male Balb/c mice Peer-reviewed

    M. Ono, T. Kikusui, N. Sasaki, M. Ichikawa, Y. Mori, K. Murakami-Murofushi

    Neuroscience　156　(4)　1103-1110　2008/10

    Publisher: Elsevier BV

    DOI： 10.1016/j.neuroscience.2008.07.078 　

    ISSN： 0306-4522

  29. Phylogeny of primary photosynthetic eukaryotes as deduced from slowly evolving nuclear genes. International-journal Peer-reviewed

    Hisayoshi Nozaki, Mineo Iseki, Masami Hasegawa, Kazuharu Misawa, Takashi Nakada, Narie Sasaki, Masakatsu Watanabe

    Molecular biology and evolution　24　(8)　1592-5　2007/08

    ISSN： 0737-4038

  30. STAT3 and PKC differentially regulate telomerase activity during megakaryocytic differentiation of K562 cells. International-journal Peer-reviewed

    Mayuka Nakatake, Yasutaka Kakiuchi, Narie Sasaki, Kimiko Murakami-Murofushi, Osamu Yamada

    Cell cycle (Georgetown, Tex.)　6　(12)　1496-501　2007/06/15

    eISSN： 1551-4005

    More details Close

    Telomerase is active in immature somatic cells, but not in differentiated cells. However, the regulation during cell differentiation is not well understood. In this study, a human chronic myelogenous leukemia cell line (K562) was induced to differentiate into megakaryocytes by TPA, and erythroid by STI571. A human acute myeloblastic leukemia cell line (HL60) was also induced to differentiate into monocytes by TPA and VD3, and granulocyte by ATRA. TPA induced transient increase of telomerase activity (mainly nuclear fraction) during megakaryocytic differentiation, while the expression of hTERT decreased gradually throughout the same period. Pretreatment with PKC inhibitors inhibited the megakaryocytic differentiation, transient increase of telomerase activity, while recombinant PKC increased telomerase activity. ChIP assay resulted STAT3 and STAT5 dissociated from the hTERT promoter, indicating that STAT3 and STAT5 are one of the transcriptional regulators. These results suggest that telomerase activity is regulated by two mechanisms during megakaryocytic differentiation.

  31. Identification of substrates for transglutaminase in Physarum polycephalum, an acellular slime mold, upon cellular mechanical damage. International-journal Peer-reviewed

    Fumitaka Wada, Hiroki Hasegawa, Akio Nakamura, Yoshiaki Sugimura, Yoshiki Kawai, Narie Sasaki, Hideki Shibata, Masatoshi Maki, Kiyotaka Hitomi

    The FEBS journal　274　(11)　2766-77　2007/06

    ISSN： 1742-464X

    More details Close

    Transglutaminases are Ca(2+)-dependent enzymes that post-translationally modify proteins by crosslinking or polyamination at specific polypeptide-bound glutamine residues. Physarum polycephalum, an acellular slime mold, is the evolutionarily lowest organism expressing a transglutimase whose primary structure is similar to that of mammalian transglutimases. We observed transglutimase reaction products at injured sites in Physarum macroplasmodia upon mechanical damage. With use of a biotin-labeled primary amine, three major proteins constituting possible transglutimase substrates were affinity-purified from the damaged slime mold. The purified proteins were Physarum actin, a 40 kDa Ca(2+)-binding protein with four EF-hand motifs (CBP40), and a novel 33 kDa protein highly homologous to the eukaryotic adenine nucleotide translocator, which is expressed in mitochondria. Immunochemical analysis of extracts from the damaged macroplasmodia indicated that CBP40 is partly dimerized, whereas the other proteins migrated as monomers on SDS/PAGE. Of the three proteins, CBP40 accumulated most significantly around injured areas, as observed by immunofluoresence. These results suggested that transglutimase reactions function in the response to mechanical injury.

  32. Species Preferentiality of the Pollen Tube Attractant Derived from the Synergid Cell of Torenia fournieri Peer-reviewed

    Tetsuya Higashiyama, Rie Inatsugi, Sachio Sakamoto, Narie Sasaki, Toshiyuki Mori, Haruko Kuroiwa, Takashi Nakada, Hisayoshi Nozaki, Tsuneyoshi Kuroiwa, Akihiko Nakano

    Plant Physiology　142　(2)　481-491　2006/10/10

    Publisher: Oxford University Press (OUP)

    DOI： 10.1104/pp.106.083832 　

    eISSN： 1532-2548

    More details Close

    Abstract The synergid cell of Torenia fournieri attracts pollen tubes by a diffusible but yet unknown chemical attractant. Here we investigated the species difference of the attractant using five closely related species in two genera, namely T. fournieri, Torenia baillonii, Torenia concolor, Lindernia (Vandellia) crustacea, and Lindernia micrantha. These five species have an exserted embryo sac, and ablation experiments confirmed that their synergid cells attracted the pollen tube. When ovules of T. fournieri and one of the other species were cultivated together with pollen tubes of each species, pollen tubes were significantly more attracted to synergid cells of the corresponding species. The attraction was not affected by the close proximity of embryo sacs of different species. This suggests that the attractant is a species-preferential molecule that is likely synthesized in the synergid cell. The calcium ion, long considered a potential attractant, could not serve as the sole attractant in these species, because elevation of the calcium ion concentration did not affect the observed attraction. In vivo crossing experiments also showed that the attraction of the pollen tube to the embryo sac was impaired when pollen tubes of different species arrived around the embryo sac, suggesting that the species preferentiality of the attractant may serve as a reproductive barrier in the final step of directional control of the pollen tube.

  33. Regulation of levels of actin threonine phosphorylation during life cycle of Physarum polycephalum Peer-reviewed

    Yuki Shirai, Narie Sasaki, Yoshiro Kishi, Akiko Izumi, Kie Itoh, Masazumi Sameshima, Tetsuyuki Kobayashi, Kimiko Murakami-Murofushi

    Cell Motility and the Cytoskeleton　63　(2)　77-87　2006/02

    Publisher: Wiley

    DOI： 10.1002/cm.20110 　

    ISSN： 0886-1544

    eISSN： 1097-0169

  34. Early zygote-specific nuclease in mitochondria of the true slime mold Physarum polycephalum Peer-reviewed

    Yohsuke Moriyama, Tomokazu Yamazaki, Hideo Nomura, Narie Sasaki, Shigeyuki Kawano

    Current Genetics　48　(5)　334-343　2005/11

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1007/s00294-005-0025-2 　

    ISSN： 0172-8083

    eISSN： 1432-0983

  35. Architectural Role of Mitochondrial Transcription Factor A in Maintenance of Human Mitochondrial DNA Peer-reviewed

    Tomotake Kanki, Kippei Ohgaki, Martina Gaspari, Claes M. Gustafsson, Atsushi Fukuoh, Narie Sasaki, Naotaka Hamasaki, Dongchon Kang

    Molecular and Cellular Biology　24　(22)　9823-9834　2004/11/15

    Publisher: Informa UK Limited

    DOI： 10.1128/mcb.24.22.9823-9834.2004 　

    ISSN： 0270-7306

    eISSN： 1098-5549

    More details Close

    ABSTRACT Mitochondrial transcription factor A (TFAM), a transcription factor for mitochondrial DNA (mtDNA) that also possesses the property of nonspecific DNA binding, is essential for maintenance of mtDNA. To clarify the role of TFAM, we repressed the expression of endogenous TFAM in HeLa cells by RNA interference. The amount of TFAM decreased maximally to about 15% of the normal level at day 3 after RNA interference and then recovered gradually. The amount of mtDNA changed closely in parallel with the daily change in TFAM while in organello transcription of mtDNA at day 3 was maintained at about 50% of the normal level. TFAM lacking its C-terminal 25 amino acids (TFAM-ΔC) marginally activated transcription in vitro. When TFAM-ΔC was expressed at levels comparable to those of endogenous TFAM in HeLa cells, mtDNA increased twofold, suggesting that TFAM-ΔC is as competent in maintaining mtDNA as endogenous TFAM under these conditions. The in organello transcription of TFAM-ΔC-expressing cells was no more than that in the control. Thus, the mtDNA amount is finely correlated with the amount of TFAM but not with the transcription level. We discuss an architectural role for TFAM in the maintenance of mtDNA in addition to its role in transcription activation.

  36. A novel pyrazolone, 4,4-dichloro-1-(2,4-dichlorophenyl)-3-methyl-5-pyrazolone, as a potent catalytic inhibitor of human telomerase Peer-reviewed

    Yasutaka Kakiuchi, Narie Sasaki, Mieko Satoh-Masuoka, Hiromu Murofushi, Kimiko Murakami-Murofushi

    Biochemical and Biophysical Research Communications　320　(4)　1351-1358　2004/08

    Publisher: Elsevier BV

    DOI： 10.1016/j.bbrc.2004.06.094 　

    ISSN： 0006-291X

  37. Transient posttranslational up-regulation of telomerase activity during megakaryocytic differentiation of K562 cells Peer-reviewed

    M Nakatake, N Sasaki, K Murakami-Murofushi, O Yamada

    Biochemical and Biophysical Research Communications　314　(4)　1080-1085　2004/02

    Publisher: Elsevier BV

    DOI： 10.1016/j.bbrc.2003.12.199 　

    ISSN： 0006-291X

  38. Mitochondrial Nucleoid and Transcription Factor A Peer-reviewed

    Tomotake Kanki, Hiroshi Nakayama, Narie Sasaki, Koji Takio, Tanfis Istiaq Alam, Naotaka Hamasaki, Dongchon Kang

    Mitochondrial Pathogenesis　61-68　2004

    Publisher: Springer Berlin Heidelberg

    DOI： 10.1007/978-3-662-41088-2_7 　

  39. Glom Is a Novel Mitochondrial DNA Packaging Protein inPhysarum polycephalumand Causes Intense Chromatin Condensation without Suppressing DNA Functions Peer-reviewed

    Narie Sasaki, Haruko Kuroiwa, Chikako Nishitani, Hiroyoshi Takano, Tetsuya Higashiyama, Tamaki Kobayashi, Yuki Shirai, Atsushi Sakai, Shigeyuki Kawano, Kimiko Murakami-Murofushi, Tsuneyoshi Kuroiwa

    Molecular Biology of the Cell　14　(12)　4758-4769　2003/12

    Publisher: American Society for Cell Biology (ASCB)

    DOI： 10.1091/mbc.e03-02-0099 　

    ISSN： 1059-1524

    eISSN： 1939-4586

    More details Close

    Mitochondrial DNA (mtDNA) is packed into highly organized structures called mitochondrial nucleoids (mt-nucleoids). To understand the organization of mtDNA and the overall regulation of its genetic activity within the mt-nucleoids, we identified and characterized a novel mtDNA packaging protein, termed Glom (a protein inducing agglomeration of mitochondrial chromosome), from highly condensed mt-nucleoids of the true slime mold, Physarum polycephalum. This protein could bind to the entire mtDNA and package mtDNA into a highly condensed state in vitro. Immunostaining analysis showed that Glom specifically localized throughout the mt-nucleoid. Deduced amino acid sequence revealed that Glom has a lysine-rich region with proline-rich domain in the N-terminal half and two HMG boxes in C-terminal half. Deletion analysis of Glom revealed that the lysine-rich region was sufficient for the intense mtDNA condensation in vitro. When the recombinant Glom proteins containing the lysine-rich region were expressed in Escherichia coli, the condensed nucleoid structures were observed in E. coli. Such in vivo condensation did not interfere with transcription or replication of E. coli chromosome and the proline-rich domain was essential to keep those genetic activities. The expression of Glom also complemented the E. coli mutant lacking the bacterial histone-like protein HU and the HMG-boxes region of Glom was important for the complementation. Our results suggest that Glom is a new mitochondrial histone-like protein having a property to cause intense DNA condensation without suppressing DNA functions.

  40. Structural and enzymatic characterization of physarolisin (formerly physaropepsin) proves that it is a unique serine-carboxyl proteinase Peer-reviewed

    Wataru Nishii, Tomoko Ueki, Rie Miyashita, Masaki Kojima, Yong-Tae Kim, Narie Sasaki, Kimiko Murakami-Murofushi, Kenji Takahashi

    Biochemical and Biophysical Research Communications　301　(4)　1023-1029　2003/02

    Publisher: Elsevier BV

    DOI： 10.1016/s0006-291x(03)00083-4 　

    ISSN： 0006-291X

  41. Cholesteryl Glucoside-induced Protection against Gastric Ulcer Peer-reviewed

    Shohko Kunimoto, Wataru Murofushi, Isao Yamatsu, Yukie Hasegawa, Narie Sasaki, Susumu Kobayashi, Tetsuyuki Kobayashi, Hiromu Murofushi, Kimiko Murakami-Murofushi

    Cell Structure and Function　28　(3)　179-186　2003

    Publisher: Japan Society for Cell Biology

    DOI： 10.1247/csf.28.179 　

    ISSN： 0386-7196

    eISSN： 1347-3700

  42. Detection and Localization of a Chloroplast-Encoded HU-Like Protein That Organizes Chloroplast Nucleoids Peer-reviewed

    Tamaki Kobayashi, Manabu Takahara, Shin-ya Miyagishima, Haruko Kuroiwa, Narie Sasaki, Niji Ohta, Motomichi Matsuzaki, Tsuneyoshi Kuroiwa

    The Plant Cell　14　(7)　1579-1589　2002/07

    Publisher: Oxford University Press (OUP)

    DOI： 10.1105/tpc.002717 　

    ISSN： 1040-4651

    eISSN： 1532-298X

  43. Characterization of a putative fusogen encoded in a mitochondrial plasmid of Physarum polycephalum Peer-reviewed

    Takano, H., Kawano, S., Sasaki, N., Kuroiwa, H., Kuroiwa, T.

    2002

  44. Pollen Tube Attraction by the Synergid Cell Peer-reviewed

    Tetsuya Higashiyama, Shizu Yabe, Narie Sasaki, Yoshiki Nishimura, Shin-ya Miyagishima, Haruko Kuroiwa, Tsuneyoshi Kuroiwa

    Science　293　(5534)　1480-1483　2001/08/24

    Publisher: American Association for the Advancement of Science (AAAS)

    DOI： 10.1126/science.1062429 　

    ISSN： 0036-8075

    eISSN： 1095-9203

    More details Close

    In flowering plants, guidance of the pollen tube to the embryo sac (the haploid female gametophyte) is critical for successful fertilization. The target embryo sac may attract the pollen tube as the final step of guidance in the pistil. We show by laser cell ablation that two synergid cells adjacent to the egg cell attract the pollen tube. A single synergid cell was sufficient to generate an attraction signal, and two cells enhanced it. After fertilization, the embryo sac no longer attracts the pollen tube, despite the persistence of one synergid cell. This cessation of attraction might be involved in blocking polyspermy.

  45. The complete DNA sequence of the mitochondrial genome of Physarum polycephalum Peer-reviewed

    H. Takano, T. Abe, R. Sakurai, Y. Moriyama, Y. Miyazawa, H. Nozaki, S. Kawano, N. Sasaki, T. Kuroiwa

    Molecular and General Genetics MGG　264　(5)　539-545　2001/01

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1007/s004380000357 　

    ISSN： 0026-8925

    eISSN： 1432-1874

  46. In vivo Conformation of Mitochondrial DNA Revealed by Pulsed-Field Gel Electrophoresis in the True Slime Mold, Physarum polycephalum Peer-reviewed

    R. Sakurai, N. Sasaki, H. Takano, T. Abe, S. Kawano

    DNA Research　7　(2)　83-91　2000/01/01

    Publisher: Oxford University Press (OUP)

    DOI： 10.1093/dnares/7.2.83 　

    ISSN： 1340-2838

    eISSN： 1756-1663

  47. In vitro DNA fragmentation of mitochondrial DNA caused by single-stranded breakage related to macroplasmodial senescence of the true slime mold, Physarum polycephalum. Peer-reviewed

    Abe, T, Takano, H, Sasaki, N, Mori, K, Kawano, S

    Curr. Genet.　37　125-135　2000

  48. Plastid gene expression during amyloplast formation in cultured tobacco cells. Peer-reviewed

    Sakai, A, Miyazawa, Y, Suzuki, T, Sasaki, N, Kawano, S, Kuroiwa, T

    J. Plant Physiol.　154　71-78　1999

  49. Comparative analysis of DNA synthesis activity in plastid-nuclei and mitochondrial-nuclei simultaneously isolated from cultured tobacco cells Peer-reviewed

    Atsushi Sakai, Takeshi Suzuki, Noriko Nagata, Narie Sasaki, Yutaka Miyazawa, Chieko Saito, Noriko Inada, Yoshiki Nishimura, Tsuneyoshi Kuroiwa

    Plant Science　140　(1)　9-19　1999/01

    Publisher: Elsevier BV

    DOI： 10.1016/s0168-9452(98)00207-6 　

    ISSN： 0168-9452

  50. DNA synthesis in isolated mitochondrial nucleoids from plasmodia of Physarum polycephalum. Peer-reviewed

    Sasaki, N, Sakai, A, Kawano, S, Kuroiwa, H, Kuroiwa, T

    Protoplasma　203　221-231　1998

  51. In situ analysis of the membrane-binding region of multiple mitochondrial DNA molecules in the mitochondrial nucleus of Physarum polycephalum. Peer-reviewed

    Sasaki, N, Suzuki, T, Kawano, S

    Cytologia　62　309-314　1997

  52. Optical isolation of individual mitochondria of Physarum polycephalum for PCR analysis. Peer-reviewed

    Kuroiwa, T, Ishibashi, K, Takano, H, Higashiyama, T, Sasaki, N, Nishimura, Y, Matsunaga, S

    Protoplasma　194　275-279　1996

  53. Localization of organelle DNA synthesis within the root apical meristem of rice. Peer-reviewed

    Suzuki, T, Sasaki, N, Sakai, A, Kawano, S, Kuroiwa, T

    J. Exp. Bot.　46　19-25　1995

  54. Behavior of mitochondria and their nuclei during amoebae cell proliferation in Physarum polycephalum. Peer-reviewed

    Sasaki, N, Suzuki, T, Ohta, T, Kawano, S, Kuroiwa, T

    Protoplasma　182　115-125　1994

Show all ︎Show first 5

Misc. 24

  1. ロンダ・シービンガー教授 基調講演（2024年11月21日）スライド（日本語訳）

    Londa Schiebinger, 佐々木 成江, 小川 眞里子

    国立研究開発法人 日本医療研究開発機構 ホームページに掲載　2025/06

  2. Novel method for real-time analysis of cell membrane adhesion molecules essential for animal and plant fertilization

    中島耕大, VALANSI Clari, 栗原大輔, 栗原大輔, 佐々木成江, PODBILEWICZ Benjamin, 東山哲也, 東山哲也, 東山哲也

    日本分子生物学会年会プログラム・要旨集(Web)　44th　2021

  3. Analysis of human RCC1 like protein WBSCR16 focusing on mitochondrial nucleoids

    松本恵実, 佐々木妙子, 佐藤良勝, 佐藤良勝, 東山哲也, 東山哲也, 佐々木成江

    日本分子生物学会年会プログラム・要旨集(Web)　44th　2021

  4. 真正粘菌の単離ミトコンドリアを用いた母性遺伝の解析

    浦川直希, 中村聡, 森山陽介, 鈴木孝征, 横川大輔, 河野重行, 桑田啓子, 東山哲也, 東山哲也, 東山哲也, 佐々木成江

    Plant Morphology　32　(1)　2020

    ISSN： 0918-9726

  5. 動物培養細胞への導入による動植物受精因子のライブ解析

    中島耕大, VALANSI Clari, 栗原大輔, 栗原大輔, 佐々木成江, PODBILEWICZ Benjamin, 東山哲也, 東山哲也, 東山哲也

    Plant Morphology　32　(1)　2020

    ISSN： 0918-9726

  6. 培養細胞を用いたライブセルイメージングによる受精因子群の解析

    中島耕大, ヴァランシー クラリー, 栗原大輔, 栗原大輔, 佐々木成江, ポドビレヴィッチ ベンジャミン, 東山哲也, 東山哲也

    日本細胞生物学会大会(Web)　71st　2019

  7. 動物培養細胞を用いた動植物の受精因子群の機能解析

    中島耕大, ヴァランシー クラリー, 栗原大輔, 栗原大輔, 佐々木成江, ポドヴィレウィック ベンジャミン, 東山哲也, 東山哲也, 東山哲也

    日本植物学会大会研究発表記録　83rd　2019

  8. 光ピンセットを用いた細胞操作による受精因子解析の試み

    中島耕大, 永原史織, 佐々木妙子, VALANSI Clari, 栗原大輔, 佐藤良勝, 佐々木成江, PODBILEWICZ Benjamin, 東山哲也, 東山哲也

    日本植物学会大会研究発表記録　82nd　2018

  9. 真正粘菌(Physarum polycephalum)由来のTectoninタンパクとその関連タンパクの解析

    松田卓也, 森田理日斗, 桑田啓子, 佐々木成江, 南善子

    日本生化学会大会(Web)　89th　2016

  10. 真正粘菌におけるバクテリア分裂因子によるミトコンドリアとミトコンドリア核様体の分裂制御

    山田佳歩, 佐々木妙子, 由比良子, 森山陽介, 東山哲也, 東山哲也, 東山哲也, 佐々木成江

    日本植物学会大会研究発表記録　78th　2014

  11. 花粉管における誘引物質LUREの受容能は雌しべ組織により多段階に制御される

    奥田哲弘, 奥田哲弘, 鈴木孝征, 鈴木孝征, 森仁志, 金岡雅浩, 佐々木成江, 東山哲也, 東山哲也, 東山哲也

    日本細胞生物学会大会要旨集　66th　2014

  12. トレニア花粉管における誘引物質LUREsの結合能獲得

    奥田哲弘, 水上茜, 鈴木孝征, 鈴木孝征, 森仁志, 金岡雅浩, 佐々木成江, 東山哲也, 東山哲也, 東山哲也

    Plant Morphology　26　(1)　2014

    ISSN： 0918-9726

  13. トレニア花粉管先端における誘引物質LUREsの受容能獲得

    奥田哲弘, 奥田哲弘, 鈴木孝征, 鈴木孝征, 森仁彦, 金岡雅浩, 佐々木成江, 東山哲也, 東山哲也, 東山哲也

    日本植物学会大会研究発表記録　77th　2013

  14. ミトコンドリア局在型RCC1様タンパク質によるミトコンドリア核様体の分裂制御

    山田佳歩, 由比良子, 佐々木妙子, 鈴木俊哉, 鈴木俊哉, 東山哲也, 東山哲也, 東山哲也, 佐々木成江

    日本植物学会大会研究発表記録　77th　2013

  15. トレニア花粉管における誘引物質LUREsの受容能獲得

    奥田哲弘, 鈴木孝征, 森仁志, 金岡雅浩, 佐々木成江, 東山哲也, 東山哲也, 東山哲也

    日本植物生理学会年会要旨集　54th　2013

  16. ヒト培養細胞を用いたミトコンドリア核様体分配機構の解析

    佐々木妙子, 山田佳歩, 由比良子, 鈴木俊哉, 鈴木俊哉, 石原直忠, 石原(伴)玲子, 東山哲也, 東山哲也, 東山哲也, 佐々木成江

    日本分子生物学会年会プログラム・要旨集(Web)　36th　2013

  17. 哺乳動物細胞におけるミトコンドリアダイナミクスと核様体の関係性

    石原(伴)玲子, 石原孝也, 佐々木成江, 三原勝芳, 石原直忠

    日本生化学会大会(Web)　86th　2013

  18. マラリア原虫ミトコンドリアの知られざる顔

    前田桂, 前田桂, 小松谷啓介, 畑昌幸, 畑昌幸, 上田貴志, 中野明彦, 中野明彦, 竹尾暁, 坪井敬文, 室伏きみ子, 北潔, 佐々木成江, 佐々木成江

    日本寄生虫学会東日本支部大会プログラム・講演要旨　71st　2011

  19. Discovery of Pollen-tube Attractants LUREs

    HIGASHIYAMA Tetsuya, OKUDA Satohiro, TSUTSUI Hiroki, SHIINA Keiko, TAKEUCHI Hidenori, KANAOKA Masahiro M., SASAKI Narie

    KAGAKU TO SEIBUTSU　47　(9)　617-623-623　2009/09

    Publisher: Japan Society for Bioscience, Biotechnology, and Agrochemistry

    DOI： 10.1271/kagakutoseibutsu.47.617 　

    ISSN： 0453-073X

  20. ライブイメージングによる重複受精機構の解明

    浜村有希, 齋藤知恵子, 佐々木成江, 中野明彦, 中野明彦, 東山哲也

    Plant Morphology　19and20　(1 (Web))　2008

    ISSN： 0918-9726

  21. Phylogeny of primary photosynthetic eukaryotes as deduced from slowly evolving nuclear genes (vol 24, pg 1592, 2007)

    Hisayoshi Nozaki, Mineo Iseki, Masami Hasegawa, Kazuharu Misawa, Takashi Nakada, Narie Sasaki, Masakatsu Watanabe

    MOLECULAR BIOLOGY AND EVOLUTION　24　(9)　2151-2151　2007/09

    ISSN： 0737-4038

  22. Purification and characterization of cyclic phosphatidic acid biosynthetic enzyme

    Satomi Tsuda, Tetsuyuki Kobayashi, Narie Sasaki, Kimiko Murakami-Murofushi

    CELL STRUCTURE AND FUNCTION　29　54-54　2004/05

    ISSN： 0386-7196

    eISSN： 1347-3700

  23. Identification and Characterization of a novel mitochondrial histone-like protein in Physarum polycephalum. Invited

    Sasaki, N

    Plant Morphol.　16　(1 (Web))　61-70　2004

    ISSN： 0918-9726

  24. 環状ホスファチジン酸生合成酵素の精製と性状解析

    津田 聡美, 小林 哲幸, 佐々木 成江, 青木 淳賢, 新井 洋由, 室伏 きみ子

    脂質生化学研究　45　193-196　2003/05

    Publisher: 日本脂質生化学会

    ISSN： 0285-1520

Show all ︎Show first 5

Books and Other Publications 6

  1. 月刊 理科の教育2025年5月号

    一般社団法人日本理科教育学会

    （株）東洋館出版社　2025/05

  2. 高校生と考える未来への想像力

    桐光学園中学校, 桐光学園高等学校, 稲垣, 諭

    左右社　2025/03

    ISBN: 9784865284638

  3. ジェンダード・イノベーションの可能性 = The potential of gendered innovations

    小川, 眞里子, 鶴田, 想人, 弓削, 尚子, Schiebinger, Londa L., 隠岐, さや香, 標葉, 隆馬, 佐々木, 成江, 村瀬, 泰菜, 伊藤, 公雄, 熊谷, 晋一郎, 綾屋, 紗月, 池田, 美奈子, 渡部, 麻衣子

    明石書店　2024/10

    ISBN: 9784750357997

  4. ミトコンドリアダイナミクス : 機能研究から疾患・老化まで

    佐々木成江

    エヌ・ティー・エス　2021/10

    ISBN: 9784860437466

  5. 細胞工学 05年8月号 24ー8 特集:細胞の生と死を司るミトコンドリア

    佐々木成江、黒岩常祥

    秀潤社　2005/07/22

    ISBN: 4879624519

  6. 新ミトコンドリア学

    佐々木成江、黒岩常祥

    共立出版　2001/11/07

    ISBN: 4320055810

Show all Show first 5

Research Projects 7

  1. Analyses of the molecular mechanism involved in the selective degradation of paternal mitochondrial DNA in maternal inheritance

    Sasaki Narie

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Nagoya University

    2018/04/01 - 2022/03/31

    More details Close

    Physarum polycephalum has large mitochondrial nucleoids, which are mitochondrial DNA (mtDNA)-protein complexes. In this study, we developed a semi-in vitro assay to detect DNase activity by microscopic observation of the digestion of mtDNA in isolated mitochondria from P. polycephalum and the DNase involved in maternal inheritance was characterized. When the mitochondria isolated from zygotes were used, the digestion of mtDNA in isolated mitochondria was specifically observed in the presence of Mg2+ and maximum activity was detected at pH 7.7. During the digestion of mtDNA, mitochondrial membrane integrity was maintained in vivo. Furthermore, we also developed a method to distinguish uniparental mitochondria in zygotes of P. polycephalum by chemical staining. Our results showed that the proliferation of maternal mitochondria rapidly occurred after the initiation of digestion of paternal mtDNA.

  2. Analysis of maternal inheritance of mitochondrial DNA using developed organelle sorter system

    SASAKI NARIE, MORIYAMA Yosuke, ITAMI Kenichirou, URAKAWA Naoki, NAKAMURA Satoru, SASAKI Taeko, TANAKA Yoriko

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Nagoya University

    2015/04/01 - 2018/03/31

    More details Close

    In many eukaryotes, mitochondrial DNA (mtDNA) is inherited maternally, which is called maternal inheritance. For maternal inheritance, selective digestion of mtDNA in paternal mitochondria is essential. However, it is unknown how mtDNA in paternal mitochondria is selectively digested by DNase after zygosis or fertilization. In this study, to identify DNase involved in maternal inheritance of mtDNA, we tried to fractionate paternal mitochondria which had no mtDNA from zygote of Physarum polycephalu using cell sorter. Since mitochondria were destroyed in the cell sorter, we couldn’t fractionate. Then, we performed proteome analysis of isolated mitodhondria from zygote by nanoLC-MS/MS. We identified nine DNases in isolated mitochondria from zygotes that had mitochondria without mtDNA.

  3. The regulation of mitochondrial nucleoid division by a mitochondrial RCC1-like protein

    SASAKI NARIE

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Nagoya University

    2011 - 2013

    More details Close

    Mitochondrial DNA (mt-DNA) is packed into a highly organized DNA-protein complex called the mitochondrial nucleoid (mt-nucleoid). Division of mt-nucleoid is necessary for mt-DNA distribution into daughter mitochondria. However, little is understood about the molecular mechanisms that regulate the mt-nucleoid division. In this study, we showed that a mitochondrial RCC1(Regulator of chromosome condensation 1)-like protein of P. polycephalum was involved in the mt-nucleoid division by controlling of the association of mt-nucleoids and cristae. We also identified a human mitochondrial RCC1-like protein (hmtRCC1). The down regulation analysis of hmtRCC1 showed that this protein might be involved in the mt-nucleoid division.

  4. Diversity of energy transducing mechanism by organella from the parasites such as Plasmodium

    KITA Kiyoshi, TANABE Kazuyuki, NOZAKI Tomoyoshi, WATANABE Yoh-ichi, SASAKI Narie

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Creative Scientific Research

    Category: Grant-in-Aid for Creative Scientific Research

    Institution: The University of Tokyo

    2006 - 2010

    More details Close

    Eukaryotic cells possess organella, which are essential for the maintenance of their biological function. By the extensive studies, many new findings on the origin, reaction mechanism and interaction of energy transducing mitochondria and plastid, which are indispensable for the survival of the cells, have been reported. Recent study revealed the unique mitochondria of parasites, which adapt to the anaerobic environment in the host as well as the parasites without mitochondria. However, information on the process of their establishment, details of their physiological functions, interaction between the organella is limited. The aim of this research project is to answer these questions and establish a base of our understanding the diversity of energy transduction in the novel organella, dynamic interaction between the organella and their evolution. In this study, by focusing on parasitic protozoas such as malaria parasite, we have found novel properties of parasite organella, which bring a new insight organella biology.

  5. 高次ミトコンドリア核様体の分子構築とDNA機能発現制御のメカニズム

    佐々木 成江

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業 若手研究(B)

    Category: 若手研究(B)

    Institution: お茶の水女子大学

    2005 - 2006

    More details Close

    生体内において、ミトコンドリアDNA(mtDNA)は高度に折りたたまれ、凝縮したミトコンドリア核様体として存在する。そして、ミトコンドリアゲノムの基本的な機能である複製や転写は、そのような高次構造をとったDNAのなかで効率よく、かつ正確に営まれている。これまでに、非常に凝縮した大型ミトコンドリア核様体を持っ真正粘菌(Physarum polycephalum)を用いて、ミトコンドリアヒストン様タンパク質であるGlomを同定し、ミトコンドリア核様体内におけるその機能を解析してきた。本研究では、ミトコンドリア核様体の分子構築とDNA機能制御機構を明らかにするために、Glomおよび他のDNA結合タンパク質について解析を行っている。 本年度は、昨年度に行ったミトコンドリア核様体タンパク質のMS/MS解析により同定された、Lon protease、Topoisomrase、DNApolymerseの遺伝子の全長cDNAのクローニングをおこなった。その結果、真正粘菌のDNA polymerseは、5'-3'エキソヌクレアーゼ、3'-5'エキソヌクレアーゼ、DNAポリメラーゼドメインを含む新規のミトコンドリアDNAポリメラーゼであることがわかった。また、ミトコンドリアDNAポリメラーゼを精製し、DNA複製能のほかにリバーストランスクリプターゼ活性も保持していることを確かめた。さらに、それぞれのタンパク質の細胞内局在を明らかにするために、それぞれの抗体を作成した。ウエスタン解析の結果、すべてのタンパク質がミトコンドリア核様体フラクションに強く濃縮されていることが分かった。

  6. Studies on mechanism for Initial Responses to Stress in Cells

    KOBAYASHI Tetsuyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Ochanomizu University

    2003 - 2004

    More details Close

    Previously, we found that heat shock stress rapidly induced sterylglucoside(SG) in human fibroblast cells and hypothesized that SG functions as a crucial lipid mediator in the process of cellular stress responses. In this study, we examined the protective effect of SG against cold-restraint stress-induced gastric ulcer in rats. (1)It was shown that cold-restraint stress induced the organ-specific accumulation of cholesterylglucoside(CG) in stomach and kidney. (2)A biosynthetic enzyme activity of CG was detected in homogenates of rat stomach. The enzyme was a membrane-bound glucosyltransferase, which uses UDP-glucose and cholesterol as substrates. (3)When CG was orally administered to rat prior to the stress application, the formation of gastric ulcer was markedly suppressed as compared to control. Orally administered CG caused the rapid activation of HSFl and the subsequent expression of HSP70 in gastric mucous cells. (4)Oral administration of SG derived from soy bean also showed the untiulcer effect, although no HSP induction was observed. These findings suggest that CG may act as a lipid mediator in an early stage of the stress signal transduction system and that SGs are effective cytoprotective agents for medical treatment of gastric ulcer.

  7. 高次ミトコンドリア核を形成する新規タンパク質による1ゲノム遺伝子セットの発現制御

    東山 成江

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業 特別研究員奨励費

    Category: 特別研究員奨励費

    Institution: お茶の水女子大学

    2000 - 2002

    More details Close

    本研究の目的は、DNA-タンパク質複合体の高次構造レベルでの複製・転写の制御機構を明らかにすることである。私は、ミトコンドリアDNAとタンパク質の高次構造体であるミトコンドリア核をモデルとして用い、解析をおこなってきた。これまでに、ミトコンドリア核の高次構造の形成に重要であるヒストンH1とHMGタンパク質の両者の性質を併せ持った新規タンパク質を真正粘菌から発見し、Glomと名づけた。このタンパク質は、ミトコンドリアDNA全長に渡って結合し、ミトコンドリアゲノム全遺伝子の機能制御に関わっていると考えられる。現在、ミトコンドリア核に含まれる他の構造タンパク質についても同様に解析を進め、包括的な理解を目指している。 新規ミトコンドリア核タンパク質の同定 以前まで使用していた単離ミトコンドリア核様体には、ミトコンドリア内膜の一部が混入していることがわかっていた。そこで、ミトコンドリア核様体を構成するタンパク質を効率よく同定するために単離法を再検討した。その結果、単離ミトコンドリア核様体を再び界而活性剤NP-40で処理することにより内膜の除去されたミトコンドリア核様体を単離することに成功した。この単離ミトコンドリア核様体を使用し、DNA-セファロースカラムやDNaseなどを用いた解析によりDNA結合タンパク質を調べた。その結果、56kDa、36kDa、34kDaがDNA結合能があることが分かった。それらのタンパク質のN末端アミノ酸配列をペプチドシークエンスにより決定した結果、すべて新規タンパク質であることが分かった。現在、ペプチドマッピングを行い内部アミノ酸配列を調べている。

Show all Show first 5