SATO, Masamitsu

写真a

Affiliation

Faculty of Science and Engineering, School of Advanced Science and Engineering

Job title

Professor

Homepage URL

http://msmicrotubule.blogspot.com/

Profile

細胞や組織において微小管などの細胞骨格はどのように形態を作り、どのような機能を担っているのかについて研究を展開しています。
特に、微小管形成の分子メカニズム、組織における微小管の形態と機能の制御、さらに細胞周期における遺伝子発現と細胞の運命決定の解析を研究しています。

Concurrent Post 【 display / non-display

  • Affiliated organization   Global Education Center

  • Faculty of Science and Engineering   Graduate School of Advanced Science and Engineering

Research Institute 【 display / non-display

  • 2020
    -
    2022

    理工学術院総合研究所   兼任研究員

Education 【 display / non-display

  •  
    -
    2001

    University of Tokyo   Graduate School of Science   Department of Biophysics and Biochemistry  

  •  
    -
    1998

    University of Tokyo   Graduate School of Science   Department of Biophysics and Biochemistry  

  •  
    -
    1996

    University of Tokyo   Faculty of Science   Department of Biophysics and Biochemistry  

Degree 【 display / non-display

  • University of Tokyo   Ph.D.

Research Experience 【 display / non-display

  • 2018.04
    -
    Now

    Waseda University   Department of Life Science and Medical Bioscience   Professor

  • 2013.04
    -
    2018.03

    Waseda University   Department of Life Science and Medical Bioscience   Associate Professor

  • 2009.09
    -
     

    ~2012.3: PRESTO researcher, JST

  • 2006.09
    -
     

    ~2013.3: Assistant Professor, Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo

  • 2006.04
    -
     

    ~2006.9: JSPS Postdoctoral Fellow for Research Abroad

display all >>

Professional Memberships 【 display / non-display

  •  
     
     

    The Molecular Biology Society of Japan

  •  
     
     

    Japan Society for Cell Biology

 

Research Areas 【 display / non-display

  • Genetics

  • Molecular biology

  • Cell biology

Research Interests 【 display / non-display

  • gene expression

  • oocyte

  • Single Cell Analysis

  • cell division

  • mitosis

display all >>

Papers 【 display / non-display

  • Mechanisms for Cellular Wake-up in Fission Yeast Revealed by Single-cell RNA-seq

    Hayato Tsuyuzaki, Masahito Hosokawa, Haruko Takeyama, Masamitsu Sato

    Bioscience and Industry (B&I)   78 ( 6 ) 507 - 509  2020.11  [Invited]

    Authorship:Last author, Corresponding author

  • Time-lapse single-cell transcriptomics reveals modulation of histone H3 for dormancy breaking in fission yeast.

    Hayato Tsuyuzaki, Masahito Hosokawa, Koji Arikawa, Takuya Yoda, Naoyuki Okada, Haruko Takeyama, Masamitsu Sato

    Nature communications   11 ( 1 ) 1265 - 1265  2020.03  [Refereed]  [International journal]

    Authorship:Last author, Corresponding author

     View Summary

    How quiescent cells break dormancy is a key issue in eukaryotic cells including cancer. Fungal spores, for example, remain quiescent for long periods until nourished, although the mechanisms by which dormancy is broken remain enigmatic. Transcriptome analysis could provide a clue, but methods to synchronously germinate large numbers of spores are lacking, and thus it remains a challenge to analyse gene expression upon germination. Hence, we develop methods to assemble transcriptomes from individual, asynchronous spore cells of fission yeast undergoing germination to assess transcriptomic changes over time. The virtual time-lapse analyses highlights one of three copies of histone H3 genes whose transcription fluctuates during the initial stage of germination. Disruption of this temporal fluctuation causes defects in spore germination despite no visible defects in other stages of the life cycle. We conclude that modulation of histone H3 expression is a crucial 'wake-up' trigger at dormancy breaking.

    DOI PubMed

  • Module-based construction of plasmids for chromosomal integration of the fission yeast Schizosaccharomyces pombe

    Yasutaka Kakui, Tomonari Sunaga, Kunio Arai, James Dodgson, Liang Ji, Attila Csikasz-Nagy, Rafael Carazo-Salas, Masamitsu Sato

    OPEN BIOLOGY   5 ( 6 )  2015.06  [Refereed]

     View Summary

    Integration of an external gene into a fission yeast chromosome is useful to investigate the effect of the gene product. An easy way to knock-in a gene construct is use of an integration plasmid, which can be targeted and inserted to a chromosome through homologous recombination. Despite the advantage of integration, construction of integration plasmids is energy-and time-consuming, because there is no systematic library of integration plasmids with various promoters, fluorescent protein tags, terminators and selection markers; therefore, researchers are often forced to make appropriate ones through multiple rounds of cloning procedures. Here, we establish materials and methods to easily construct integration plasmids. We introduce a convenient cloning system based on Golden Gate DNA shuffling, which enables the connection of multiple DNA fragments at once: any kind of promoters and terminators, the gene of interest, in combination with any fluorescent protein tag genes and any selection markers. Each of those DNA fragments, called a 'module', can be tandemly ligated in the order we desire in a single reaction, which yields a circular plasmid in a one-step manner. The resulting plasmids can be integrated through standard methods for transformation. Thus, these materials and methods help easy construction of knock-in strains, and this will further increase the value of fission yeast as a model organism.

    DOI PubMed

  • The Kinetochore Protein Kis1/Eic1/Mis19 Ensures the Integrity of Mitotic Spindles through Maintenance of Kinetochore Factors Mis6/CENP-I and CENP-A

    Hayato Hirai, Kunio Arai, Ryo Kariyazono, Masayuki Yamamoto, Masamitsu Sato

    PLOS ONE   9 ( 11 ) e111905  2014.11  [Refereed]

     View Summary

    Microtubules play multiple roles in a wide range of cellular phenomena, including cell polarity establishment and chromosome segregation. A number of microtubule regulators have been identified, including microtubule-associated proteins and kinases, and knowledge of these factors has contributed to our molecular understanding of microtubule regulation of each relevant cellular process. The known regulators, however, are insufficient to explain how those processes are linked to one another, underscoring the need to identify additional regulators. To find such novel mechanisms and microtubule regulators, we performed a screen that combined genetics and microscopy for fission yeast mutants defective in microtubule organization. We isolated approximately 900 mutants showing defects in either microtubule organization or the nuclear envelope, and these mutants were classified into 12 categories. We particularly focused on one mutant, kis1, which displayed spindle defects in early mitosis. The kis1 mutant frequently failed to assemble a normal bipolar spindle. The responsible gene encoded a kinetochore protein, Mis19 (also known as Eic1), which localized to the interface of kinetochores and spindle poles. We also found that the inner kinetochore proteins Mis6/CENP-I and Cnp1/CENP-A were delocalized from kinetochores in the kis1 cells and that kinetochore-microtubule attachment was defective. Another mutant, mis6, also displayed similar spindle defects. We conclude that Kis1 is required for inner kinetochore organization, through which Kis1 ensures kinetochore-microtubule attachment and spindle integrity. Thus, we propose an unexpected relationship between inner kinetochore organization and spindle integrity.

    DOI

  • CDK-dependent phosphorylation of Alp7-Alp14 (TACC-TOG) promotes its nuclear accumulation and spindle microtubule assembly

    Naoyuki Okada, Takashi Toda, Masayuki Yamamoto, Masamitsu Sato

    MOLECULAR BIOLOGY OF THE CELL   25 ( 13 ) 1969 - 1982  2014.07  [Refereed]

     View Summary

    As cells transition from interphase to mitosis, the microtubule cytoskeleton is reorganized to form the mitotic spindle. In the closed mitosis of fission yeast, a microtubule-associated protein complex, Alp7-Alp14 (transforming acidic coiled-coil-tumor overexpressed gene), enters the nucleus upon mitotic entry and promotes spindle formation. However, how the complex is controlled to accumulate in the nucleus only during mitosis remains elusive. Here we demonstrate that Alp7-Alp14 is excluded from the nucleus during interphase using the nuclear export signal in Alp14 but is accumulated in the nucleus during mitosis through phosphorylation of Alp7 by the cyclin-dependent kinase (CDK). Five phosphorylation sites reside around the nuclear localization signal of Alp7, and the phosphodeficient alp7-5A mutant fails to accumulate in the nucleus during mitosis and exhibits partial spindle defects. Thus our results reveal one way that CDK regulates spindle assembly at mitotic entry: CDK phosphorylates the Alp7-Alp14 complex to localize it to the nucleus.

    DOI

display all >>

Misc 【 display / non-display

  • Systems level understanding of cell polarity regulation

    Attila Csikasz-Nagy, Federico Vaggi, James Dodgson, Anatole Chessel, Marco Geymonat, Marco Giordan, Kunio Arai, Masamitsu Sato, Rafael Edgardo Carazo Salas

    YEAST   32   S247 - S247  2015.09

    Research paper, summary (international conference)  

Awards 【 display / non-display

  • Waseda University Research Award

    2018.02  

    Winner: SATO, Masamitsu

  • Waseda University Teaching Award, The President Award

    2018   Waseda University  

  • Waseda University Teaching Award

    2016.12  

    Winner: SATO, Masamitsu

  • The Young Scientists’ Prize, The Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology

    2012.04  

  • Human Frontier Science Program (HFSP) Young Investigator Grant

    2009.09  

display all >>

Research Projects 【 display / non-display

  • Regulatory mechanisms of meiosis

  • Cell cycle regulation specific to the interkinesis period between Meiosis I and Meiosis II

  • Analysis of novel functions of microtubules that bridge meiotic recombination and chromosome segregation

  • Regulatory Mechanisms of Meiosis in Fission Yeast

  • 減数分裂における細胞分裂装置の再編成機構

    特定領域研究

display all >>

Specific Research 【 display / non-display

  • 微小管の時空間的制御のメカニクス異常が原因で起きる疾患を組織レベルで追究する

    2020  

     View Summary

    微小管は細胞内に形成される繊維状の骨組み因子として知られる。微小管の機能は多岐にわたるが、未だに明らかにされていない機能があると考えられ、我々はそのような微小管の新規構造・新機能の発見を目指して研究を遂行している。これまでの研究の結果、微小管の制御が破綻することで、小腸上皮細胞の形態に異常が発生することが明らかにされている。そこで我々は、微小管結合タンパク質CAMSAP3の異常がどのようなメカニズムで細胞形態の異常を引き起こすのか、組織学的な解析をおこなった。解析の結果、微小管の異常が細胞小器官の配置異常を引き起こすことで、細胞の形態や機能に影響をもたらす可能性があると推測するに至った。

  • シングルセル・オミクス解析による、細胞が休眠から目覚める分子機構の解明

    2019  

     View Summary

    本研究では、休眠状態の細胞が、周囲の環境の変化に伴い休眠を打破して活動を開始する際に、どのような分子機構が働くのか、その解明を目指している。分裂酵母は減数分裂の結果として配偶子に相当する胞子を形成する。胞子は栄養に乏しい状態でも長期にわたり休眠状態を維持するが、周囲の栄養状態が改善すると、これを認識して発芽をおこない、その後通常見られるような体細胞分裂周期に入り、増殖を繰り返す。我々は休眠打破の分子機構を解明するために、遺伝子発現解析をおこなうことで、休眠から発芽にかけて、どのような遺伝子が発現変動するのかを調べた。

  • クロマチン動態解析のためのシングルセル・オミクス基盤技術の整備

    2018  

     View Summary

    本研究では、分裂酵母におけるシングルセルにもとづく遺伝子発現解析を可能とする実験手法を確立することを目的としている。本研究の成果として、栄養増殖状態にある分裂酵母の1個の細胞からRNAを抽出し、これをRNA-seq法により発現解析することをおこなった。その結果として得られた発現プロファイルは、既存の方法で作成された発現プロファイルと極めて高い相関性を示したため、本方法が有効であることが示された。

  • 高齢卵子における微小管異常と不妊との関連

    2017  

     View Summary

    出産の高齢化や不妊がおおきな社会問題となっている昨今,その原因を追究して不妊治療に応用する必要性が重視されてきている。しかしながら現段階では,これらの原因はじゅうぶんに追究されていない。そこで本研究では,ほ乳類の減数分裂(卵母細胞形成)に焦点を当てて,卵母細胞の経年劣化の原因の一端を探りたいと考えた。我々は紡錘体微小管に注目し,この異常が卵子の経年劣化や不妊の原因となっている可能性について実験をおこない,今後の研究の質的な基盤を固めたいと考えた。

  • 構造クラスタ分類によるncRNA新機能の発見

    2017  

     View Summary

    分裂酵母S. pombeにおいては,およそ1,800種類の非コードRNAが存在することが知られている。これらには細胞内でなんらかの機能を発揮するものがあると考えられるが,これまでのところ機能が解明されているものはごく一部のみであり,大部分は機能未定の状態である。そこで本研究では,これらの非コードRNAのなかから細胞内で何らかの機能を発揮するものを探索することを主目的としてスクリーンをおこなっている。

display all >>

 

Syllabus 【 display / non-display

display all >>