Name

SATO, Masamitsu

Official Title

Professor

Affiliation

(School of Advanced Science and Engineering)

Contact Information

Mail Address

Mail Address
masasato@waseda.jp

URL

Web Page URL

http://msmicrotubule.blogspot.com/

http://www.sato.biomed.sci.waseda.ac.jp/

Grant-in-aids for Scientific Researcher Number
50447356

Sub-affiliation

Sub-affiliation

Faculty of Science and Engineering(Graduate School of Advanced Science and Engineering)

Research Council (Research Organization)/Affiliated organization(Global Education Center)

Affiliated Institutes

構造生物・創薬研究所

研究所員 2015-

グローバルバイオメディカルグリーンサイエンス研究所

研究所員 2017-2018

構造生物・創薬研究所

プロジェクト研究所所長 2018-2019

理工学術院総合研究所(理工学研究所)

兼任研究員 2018-

Educational background・Degree

Educational background

-1996 University of Tokyo Faculty of Science Department of Biophysics and Biochemistry
-1998 University of Tokyo Graduate School of Science Department of Biophysics and Biochemistry
-2001 University of Tokyo Graduate School of Science Department of Biophysics and Biochemistry

Degree

Ph.D. Coursework University of Tokyo Genetics/Chromosome dynamics

Career

2013/04-~Present: Associate Professor, Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University
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
2002/04-~2006.9: Postdoctoral Fellow, Cancer Research UK, London Research Institute
2001/04-~2002.3: Research Fellow, University of Tokyo

Academic Society Joined

Japan Society for Cell Biology

The Molecular Biology Society of Japan

Yeast Genetics Society of Japan

Award

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

JSPS Fellowship for Research Abroad

2006/04

Research Field

Keywords

Cytoskeleton, Cell Cycle, Microtubule, Epithelial Tissue, Nuclear Dynamics, Centromere, Nucleosome, Chromosome Segregation, Mitosis and Meiosis, Fission Yeast, Chemical Genetics

Grants-in-Aid for Scientific Research classification

Biology / Biological Science / Cell biology

Biology / Biological Science / Molecular biology

Biology / Basic biology / Genetics/Chromosome dynamics

Research interests Career

Research on Microtubule Regulation

Current Research Theme Keywords:Cell division, Cell Cycle, Cytoskeleton, Chromosome Regulation, Meiosis

Individual research allowance

Paper

Kinetochore-mediated outward force promotes spindle pole separation in fission yeast.

Yutaka Shirasugi and Masamitsu Sato

Molecular biology of the cell Peer Review Yes 30(22) p.2802 - 28132019/10-

DOI

CLASP promotes microtubule bundling in metaphase spindle independently of Ase1/PRC1 in fission yeast

Hirohisa Ebina, Liang Ji, Masamitsu Sato

Biology Open Peer Review Yes 2019/10-

DOI

Time-lapse single-cell transcriptomics reveals modulation of histone H3 for dormancy breaking

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

bioRxiv 2019/08-

DOI

Module-based systematic construction of plasmids for episomal gene expression in fission yeast

Kiriya, Keita; Tsuyuzaki, Hayato; Tsuyuzaki, Hayato; Sato, Masamitsu; Sato, Masamitsu

Gene 637p.14 - 242017/12-2017/12

PubMedDOIScopus

Detail

ISSN:03781119

Outline:© 2017 Elsevier B.V. The fission yeast Schizosaccharomyces pombe is a powerful model organism for cell biology and molecular biology, as genetic manipulation is easily achieved. Introduction of exogenous genes cloned in episomal plasmids into yeast cells can be done through well-established transformation methods. For expression of genes in S. pombe cells, the multi-copy plasmid pREP1 and its derivatives, including pREP41 and pREP81, have been widely used as vectors. Although recent advancement of technology brought a number of useful genetic elements such as new promoters, selection marker genes and fluorescent protein tags, introduction of those elements into conventional pREP1 requires a large commitment of both time and effort because cloning procedures need to be repeated until the final products are constructed. Here, we introduce materials and methods to construct many pREP1-type plasmids easily and systematically using the Golden Gate shuffling method, which enables one-step ligation of many DNA fragments into a plasmid. These materials and methods support creation of expression plasmids employing a variety of novel genetic elements, which will further facilitate genetic studies using S. pombe.

Differentiating the roles of microtubule-associated proteins at meiotic kinetochores during chromosome segregation

Kakui, Yasutaka; Sato, Masamitsu

Chromosoma 2016/01-2016/01

DOIScopus

Detail

ISSN:00095915

Outline:© 2015 Springer-Verlag Berlin Heidelberg Meiosis is a specialised cell division process for generating gametes. In contrast to mitosis, meiosis involves recombination followed by two consecutive rounds of cell division, meiosis I and II. A vast field of research has been devoted to understanding the differences between mitotic and meiotic cell divisions from the viewpoint of chromosome behaviour. For faithful inheritance of paternal and maternal genetic information to offspring, two events are indispensable: meiotic recombination, which generates a physical link between homologous chromosomes, and reductional segregation, in which homologous chromosomes move towards opposite poles, thereby halving the ploidy. The cytoskeleton and its regulators play specialised roles in meiosis to accomplish these divisions. Recent studies have shown that microtubule-associated proteins (MAPs), including tumour overexpressed gene (TOG), play unique roles during meiosis. Furthermore, the conserved mitotic protein kinase Polo modulates MAP localisation in meiosis I. As Polo is a well-known regulator of reductional segregation in meiosis, the evidence suggests that Polo constitutes a plausible link between meiosis-specific MAP functions and reductional segregation. Here, we review the latest findings on how the localisation and regulation of MAPs in meiosis differ from those in mitosis, and we discuss conservation of the system between yeast and higher eukaryotes.

Mad1 promotes chromosome congression by anchoring a kinesin motor to the kinetochore.

Takeshi Akera, Yuhei Goto, Masamitsu Sato, Masayuki Yamamoto, Yoshinori Watanabe

Nature Cell Biology 17(9) p.1124 - 11332015/09-2015

PubMedDOI

Detail

Outline:For proper partitioning of genomes in mitosis, all chromosomes must be aligned at the spindle equator before the onset of anaphase. The spindle assembly checkpoint (SAC) monitors this process, generating a ‘wait anaphase’ signal at unattached kinetochores of misaligned chromosomes. However, the link between SAC activation and chromosome alignment is poorly understood. Here we show that Mad1, a core SAC component, plays a hitherto concealed role in chromosome alignment. Protein–protein interaction screening revealed that fission yeast Mad1 binds the plus-end-directed kinesin-5 motor protein Cut7 (Eg5 homologue), which is generally thought to promote spindle bipolarity. We demonstrate that Mad1 recruits Cut7 to kinetochores of misaligned chromosomes and promotes chromosome gliding towards the spindle equator. Similarly, human Mad1 recruits another kinetochore motor CENP-E, revealing that Mad1 is the conserved dual-function protein acting in SAC activation and chromosome gliding. Our results suggest that the mitotic checkpoint has co-evolved with a mechanism to drive chromosome congression.

Spatiotemporal Regulation of Nuclear Transport Machinery and Microtubule Organization.

Naoyuki Okada, Masamitsu Sato

Cells 4(3) p.406 - 4262015/08-2015

PubMedDOI

Detail

Outline:Spindle microtubules capture and segregate chromosomes and, therefore, their assembly is an essential event in mitosis. To carry out their mission, many key players for microtubule formation need to be strictly orchestrated. Particularly, proteins that assemble the spindle need to be translocated at appropriate sites during mitosis. A small GTPase (hydrolase enzyme of guanosine triphosphate), Ran, controls this translocation. Ran plays many roles in many cellular events: nucleocytoplasmic shuttling through the nuclear envelope, assembly of the mitotic spindle, and reorganization of the nuclear envelope at the mitotic exit. Although these events are seemingly distinct, recent studies demonstrate that the mechanisms underlying these phenomena are substantially the same as explained by molecular interplay of the master regulator Ran, the transport factor importin, and its cargo proteins. Our review focuses on how the transport machinery regulates mitotic progression of cells. We summarize translocation mechanisms governed by Ran and its regulatory proteins, and particularly focus on Ran-GTP targets in fission yeast that promote spindle formation. We also discuss the coordination of the spatial and temporal regulation of proteins from the viewpoint of transport machinery. We propose that the transport machinery is an essential key that couples the spatial and temporal events in cells.

Cell cycle control of spindle pole body duplication and splitting by Sfi1 and Cdc31 in fission yeast

Imène B Bouhlel, Midori Ohta, Adeline Mayeux, Nicole Bordes, Florent Dingli, Jérôme Boulanger, Guilhem Velve Casquillas, Damarys Loew, Phong T Tran, Masamitsu Sato, Anne Paoletti

Journal of Cell Science 128(8) p.1481 - 14932015/04-2015

DOIWoS

Detail

ISSN:0021-9533

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

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

OPEN BIOLOGY 5(6) 2015-2015

PubMedDOIScopus

Detail

ISSN:2046-2441

Outline:© 2015 The Authors. 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 timeconsuming, 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.

Spatiotemporal Regulation of Nuclear Transport Machinery and Microtubule Organization.

Okada Naoyuki;Sato Masamitsu

Spatiotemporal Regulation of Nuclear Transport Machinery and Microtubule Organization. 4(3) 2015-2015

DOI

Detail

ISSN:2073-4409

Outline::Spindle microtubules capture and segregate chromosomes and, therefore, their assembly is an essential event in mitosis. To carry out their mission, many key players for microtubule formation need to be strictly orchestrated. Particularly, proteins that assemble the spindle need to be translocated at appropriate sites during mitosis. A small GTPase (hydrolase enzyme of guanosine triphosphate), Ran, controls this translocation. Ran plays many roles in many cellular events: nucleocytoplasmic shuttling through the nuclear envelope, assembly of the mitotic spindle, and reorganization of the nuclear envelope at the mitotic exit. Although these events are seemingly distinct, recent studies demonstrate that the mechanisms underlying these phenomena are substantially the same as explained by molecular interplay of the master regulator Ran, the transport factor importin, and its cargo proteins. Our review focuses on how the transport machinery regulates mitotic progression of cells. We summarize translocation mechanisms governed by Ran and its regulatory proteins, and particularly focus on Ran-GTP targets in fission yeast that promote spindle formation. We also discuss the coordination of the spatial and temporal regulation of proteins from the viewpoint of transport machinery. We propose that the transport machinery is an essential key that couples the spatial and temporal events in cells.

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) p.e1119052014/11-2014

DOIWoS

Detail

ISSN:1932-6203

Targeting Alp7/TACC to the spindle pole body is essential for mitotic spindle assembly in fission yeast

Ngang Heok Tang, Naoyuki Okada, Chii Shyang Fong, Kunio Arai, Masamitsu Sato, Takashi Toda

FEBS Letters 558(17) p.2814 - 28212014/08-2014

DOIWoS

Detail

ISSN:0014-5793

Outline::The conserved TACC protein family localises to the centrosome (the spindle pole body, SPB in fungi) and mitotic spindles, thereby playing a crucial role in bipolar spindle assembly. However, it remains elusive how TACC proteins are recruited to the centrosome/SPB. Here, using fission yeast Alp7/TACC, we have determined clustered five amino acid residues within the TACC domain required for SPB localisation. Critically, these sequences are essential for the functions of Alp7, including proper spindle formation and mitotic progression. Moreover, we have identified pericentrin-like Pcp1 as a loading factor to the mitotic SPB, although Pcp1 is not a sole platform.

Functional significance of nuclear export and mRNA binding of meiotic regulator Spo5 in fission yeast

Naoyuki Togashi, Akira Yamashita, Masamitsu Sato, Masayuki Yamamoto

BMC Microbiology 14(1) p.1882014/07-2014

DOIWoS

Detail

ISSN:1471-2180

Optimization of the analogue-sensitive Cdc2/Cdk1 mutant by in vivo selection eliminates physiological limitations to its use in cell cycle analysis

Yuki Aoi, Shigehiro A Kawashima, Viesturs Simanis, Masayuki Yamamoto, Masamitsu Sato

Open Biology 4(7) p.1400632014/07-2014

DOIWoS

Detail

ISSN:2046-2441

Outline::Analogue-sensitive (as) mutants of kinases are widely used to selectively inhibit a single kinase with few off-target effects. The analogue-sensitive mutant cdc2-as of fission yeast (Schizosaccharomyces pombe) is a powerful tool to study the cell cycle, but the strain displays meiotic defects, and is sensitive to high and low temperature even in the absence of ATP-analogue inhibitors. This has limited the use of the strain for use in these settings. Here, we used in vivo selection for intragenic suppressor mutations of cdc2-as that restore full function in the absence of ATP-analogues. The cdc2-asM17 underwent meiosis and produced viable spores to a similar degree to the wild-type strain. The suppressor mutation also rescued the sensitivity of the cdc2-as strain to high and low temperature, genotoxins and an anti-microtubule drug. We have used cdc2-asM17 to show that Cdc2 activity is required to maintain the activity of the spindle assembly checkpoint. Furthermore, we also demonstrate that maintenance of the Shugoshin Sgo1 at meiotic centromeres does not require Cdc2 activity, whereas localization of the kinase aurora does. The modified cdc2-asM17 allele can be thus used to analyse many aspects of cell-cycle-related events in fission yeast.

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) p.1969 - 19822014/04-2014

DOIWoS

Detail

ISSN:1059-1524

Outline::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.

Dissecting the first and the second meiotic divisions using a marker-less drug-hypersensitive fission yeast

Yuki Aoi, Masamitsu Sato, Takashi Sutani, Katsuhiko Shirahige, Tarun M Kapoor, Shigehiro A Kawashima

Cell cycle 13(8) p.1327 - 13342014/04-2014

DOIWoS

Detail

ISSN:1538-4101

Outline::Faithful chromosome segregation during meiosis is indispensable to prevent birth defects and infertility. Canonical genetic manipulations have not been very useful for studying meiosis II, since mutations of genes involved in cell cycle regulation or chromosome segregation may affect meiosis I, making interpretations of any defects observed in meiosis II complicated. Here we present a powerful strategy to dissect meiosis I and meiosis II, using chemical inhibitors in genetically tractable model organism fission yeast (Schizosaccharomyces pombe). As various chemical probes are not active in fission yeast, mainly due to an effective multidrug resistance (MDR) response, we have recently developed a drug-hypersensitive MDR-sup strain by suppression of the key genes responsible for MDR response. We further developed the MDR-supML (marker-less) strain by deleting 7 MDR genes without commonly used antibiotic markers. The new strain makes fluorescent tagging and gene deletion much simpler, which enables effective protein visualization in varied genetic backgrounds. Using the MDR-supML strain with chemical inhibitors and live cell fluorescence microscopy, we established cell cycle arrest at meiosis I and meiosis II and examined Aurora-dependent spindle assembly checkpoint (SAC) regulation during meiosis. We found that Aurora B/Ark1 kinase activity is required for recruitment of Bub1, an essential SAC kinase, to unattached kinetochore in prometaphase I and prometaphase II as in mitosis. Thus, Aurora's role in SAC activation is likely conserved in mitosis, meiosis I, and meiosis II. Together, our MDR-supML strain will be useful to dissect complex molecular mechanisms in mitosis and 2 successive meiotic divisions.

The RNA-binding protein Spo5 promotes meiosis II by regulating cyclin Cdc13 in fission yeast

Mayumi Arata, Masamitsu Sato, Akira Yamashita, Masayuki Yamamoto

Genes to Cells 19(3) p.225 - 2382014/03-2014

DOIWoS

Detail

ISSN:1356-9597

A network approach to mixing delegates at meetings

Federico Vaggi, Tommaso Schiavinotto, Jonathan Ld Lawson, Anatole Chessel, James Dodgson, Marco Geymonat, Masamitsu Sato, Rafael Edgardo Carazo Salas, Attila Csikász-Nagy

eLife 3p.e022732014/02-

DOI

The kinetochore protein Kis1/Eic1/Mis19 ensures the integrity of mitotic spindles through maintenance of kinetochore factors Mis6/CENP-I and CENP-A.

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

The kinetochore protein Kis1/Eic1/Mis19 ensures the integrity of mitotic spindles through maintenance of kinetochore factors Mis6/CENP-I and CENP-A. 9(11) 2014-2014

DOI

Detail

ISSN:1932-6203

Outline::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.

Projecting cell polarity into the next decade Introduction.

Attila Csikász-Nagy, Masamitsu Sato, Rafael E. Carazo Salas

Philosophical Transactions of The Royal Society B Biological Sciences 368(1629) p.201300012013/11-2013

DOIWoS

Detail

ISSN:0962-8436

Dynamics of SIN Asymmetry Establishment.

Archana Bajpai, Anna Feoktistova, Jun-Song Chen, Dannel McCollum, Masamitsu Sato, Rafael E Carazo-Salas, Kathleen L Gould, Attila Csikász-Nagy

PLoS Computational Biology 9(7) p.e10031472013/07-2013

DOIWoS

Detail

ISSN:1553-7358

Microtubules and Alp7_Alp14 (TACC_TOG) reposition chromosomes before meiotic segregation

Yasutaka Kakui, *Masamitsu Sato, Naoyuki Okada, Takashi Toda and Masayuki Yamamoto

Nature Cell Biology 15(7) p.786 - +2013/06-2013

DOIWoS

Detail

ISSN:1465-7392

Spatial segregation of polarity factors into distinct cortical clusters is required for cell polarity control.

James Dodgson, Anatole Chessel, Miki Yamamoto, Federico Vaggi, Susan Cox, Edward Rosten, David Albrecht, Marco Geymonat, Attila Csikasz-Nagy, Masamitsu Sato, Rafael E. Carazo-Salas

Nature Communications 4p.18342013/06-

DOI

Cuf2 boosts the transcription of APC/C activator Fzr1 to terminate the meiotic division cycle.

Yuki Aoi, Kunio Arai, Masaya Miyamoto, Yuji Katsuta, Akira Yamashita, *Masamitsu Sato and *Masayuki Yamamoto

EMBO reports 2013-

DOI

Interpolar microtubules are dispensable in fission yeast meiosis II

Takashi Akera, *Masamitsu Sato and *Masayuki Yamamoto

Nature Communications 3p.6952012-

DOI

Polo kinase reconstitutes the spindle pole body during fission yeast meiosis

Midori Ohta, *Masamitsu Sato and *Masayuki Yamamoto

Molecular Biology of the Cell 23(10) p.1799 - 18112012-

DOI

SCF ensures meiotic chromosome segregation through a resolution of meiotic recombination intermediates

Shin-ya Okamoto, *Masamitsu Sato, Takashi Toda and *Masayuki Yamamoto

PLoS ONE 7(1) p.e00306222012-

DOI

Linkers of cell polarity and cell cycle regulation in the fission yeast protein interaction network

Federico Vaggi, James Dodgson, Archana Bajpai, Anatole Chessel, Ferenc Jord_n, Masamitsu Sato, Rafael Edgardo Carazo-Salas, Attila Csik_sz-Nagy.

PLoS Computational Biology 8(10) p.e1002732012-

DOI

A novel fission yeast mei4 mutant that allows efficient synchronization of telomere dispersal and the first meiotic division.

Yasutaka Kakui, Masamitsu Sato, Kayoko Tanaka and Masayuki Yamamoto.

Yeast 28(6) p.467 - 4792011-

DOI

Nuclear compartmentalization is abolished during fission yeast meiosis.

Kunio Arai, Masamitsu Sato, Kayoko Tanaka and Masayuki Yamamoto.

Current Biology 20(21) p.1913 - 19182010-

DOI

Space shuttling in the cell: Nucleocytoplasmic transport and microtubule organization during the cell cycle.

*Masamitsu Sato and *Takashi Toda.

Nucleus 1(3) p.231 - 2362010-

DOI

Fission yeast Pcp1 links polo kinase-mediated mitotic entry to γ-tubulin-dependent spindle formation.

Chii Shyang Fong, Masamitsu Sato and Takashi Toda.

EMBO Journal 19p.120 - 1302010-

DOI

Nucleocytoplasmic transport of Alp7/TACC organizes spatiotemporal microtubule formation in fission yeast

Masamitsu Sato, Naoyuki Okada, Yasutaka Kakui, Masayuki Yamamoto, Minoru Yoshida and Takashi Toda

EMBO reports 10(10) p.1161 - 11672009-

DOI

Visualization of fluorescence-tagged proteins in fission yeast and the analysis of mitotic spindle dynamics using GFP-tubulin under the native promoter.

*Masamitsu Sato, Mika Toya and *Takashi Toda.

Methods in Molecular Biology - Mitosis 545p.185 - 2032009-

DOI

[Is spindle formation in fission yeast specific to the species?: from the viewpoint of nuclear transport and spindle pole body].

*Masamitsu Sato, Mika Toya and *Takashi Toda.

Tanpakushitsu Kakusan Koso 53(3) p.197 - 2962008-

Gamma-tubulin complex-mediated anchoring of spindle microtubules to spindle-pole bodies requires Msd1 in fission yeast.

Mika Toya, Masamitsu Sato, Uta Haselmann, Kazuhide Asakawa, Damian Brunner, Claude Antony and Takashi Toda

Nature Cell Biology 9(6) p.646 - 6532007-

Alp7/TACC is a crucial target in Ran-GTPase-dependent spindle formation in fission yeast.

*Masamitsu Sato and *Takashi Toda.

Nature 447(7142) p.334 - 3372007-

Mal3, the fission yeast EB1 homologue, cooperates with Bub1 spindle checkpoint to prevent monopolar attachment.

Kazuhide Asakawa, Mika Toya, Masamitsu Sato, Kanai M, Kume K, Goshima T, Garcia MA, Dai Hirata, Takashi Toda

EMBO reports 6(12) p.1194 - 12002005-

New drug-resistant cassettes for gene disruption and epitope tagging in Schizosaccharomyces pombe.

Masamitsu Sato, Susheela Dhut and Takashi Toda.

Yeast 22(7) p.583 - 5912005-

The roles of fission yeast ase1 in mitotic cell division, meiotic nuclear oscillation, and cytokinesis checkpoint signaling.

Akira Yamashita#, Masamitsu Sato#, Akiko Fujita, Masayuki Yamamoto and Takashi Toda (# equal contribution)

Molecular Biology of the Cell 16(3) p.1378 - 13952005-

Interdependency of fission yeast Alp14/TOG and coiled coil protein Alp7 in microtubule localization and bipolar spindle formation.

Masamitsu Sato, Leah Vardy, Miguel Angel Garcia, Nirada Koonrugsa and Takashi Toda

Molecular Biology of the Cell 15(4) p.1609 - 16222004-

Deletion of Mia1/Alp7 activates Mad2-dependent spindle assembly checkpoint in fission yeast.

Mamamitsu Sato, Nirada Koonrugsa, Leah Vardy, Silvie Tournier, Jonathan B. Millar and Takashi Toda

Nature Cell Biology 5(9) p.764 - 7692003-

14-3-3 protein interferes with the binding of RNA to the phosphorylated form of fission yeast meiotic regulator Mei2p.

Masamitsu Sato, Yoshinori Watanabe, Yuji Akiyoshi and Masayuki Yamamoto

Current Biology 12(2) p.141 - 1452002-

The fission yeast meiotic regulator Mei2p undergoes nucleocytoplasmic shuttling.

Masamitsu Sato, Satoko Shinozaki-Yabana, Akira Yamashita, Yoshinori Watanabe and Masayuki Yamamoto

FEBS Letters 499(3) p.251 - 2552001-

Research Grants & Projects

Grant-in-aids for Scientific Research Adoption Situation

Research Classification:

Functions and Control of Microtubules from cells to tissues

2016/04-2019/03

Research Field:Cell Biology

Allocation Class:¥13400000

Research Classification:

Reconstitution of CENP-A nucleosomes and kinetochores of fission yeast

2016/04-2018/03

Research Field:Chromatin Structure, Dynamics and Function

Allocation Class:¥9360000

Research Classification:

Elucidating mechanisms for microtubule formation and new functions of microtubules

2013/-0-2016/-0

Allocation Class:¥17940000

Research Classification:

Regulatory Mechanisms of Meiosis in Fission Yeast

2009/-0-2014/-0

Allocation Class:¥207740000

Research Classification:

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

Allocation Class:¥24440000

Research Classification:

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

Allocation Class:¥3850000

Research Classification:

Regulatory mechanisms of meiosis

Allocation Class:¥354770000

Research Classification:

Controlling Microtubules: from cells to tissues

2016/-0-2019/-0

Allocation Class:¥17420000

Research Classification:

Reconstructing kinetochores and CENP-A nucleosomes

2016/-0-2018/-0

Allocation Class:¥9360000

On-campus Research System

Special Research Project

学際的アプローチによる細胞極性制御メカニズムの解明

2013

Research Results Outline: 細胞が増殖・分化をおこなって組織を形成するにあたり、細胞の形態が重要な役割を担うことが一般的に知られている。細胞形態のなかでも、特に細胞が特定の方向 細胞が増殖・分化をおこなって組織を形成するにあたり、細胞の形態が重要な役割を担うことが一般的に知られている。細胞形態のなかでも、特に細胞が特定の方向に伸張する、いわゆる細胞の極性成長は、細胞の非対称分裂と分化、および3次元的にひろがっていく細胞の... 細胞が増殖・分化をおこなって組織を形成するにあたり、細胞の形態が重要な役割を担うことが一般的に知られている。細胞形態のなかでも、特に細胞が特定の方向に伸張する、いわゆる細胞の極性成長は、細胞の非対称分裂と分化、および3次元的にひろがっていく細胞の組織化において重要なファクターである。 しかしながら、細胞がどのように成長する極性を作り出しているのか、その分子メカニズムについては未知の部分が多い。そこで我々は、細長い極性をもって成長する分裂酵母をモデル生物として用いて、細胞極性が確立される分子メカニズムの解明を目指している。 多くの研究者がこの難題に取り組んだ成果として、これまでに100種類を超える「極性因子」が発見されており、これらの多くは、細胞が成長する末端に局在する性質を持つ(for review, Hachet et al., Curr Opin Cell Biol 2012)。我々は、これらの因子の中で、まずTea1とTea3という2つのタンパク質に注目した。Tea1もTea3も、通常の顕微鏡解析においては、細胞の末端に局在し、協調して働くと考えられていた(Mata and Nurse, Cell 1997; Arellano et al., Curr Biol. 2002)。 しかしながら、我々は、ケンブリッジ大学Carazo-Salas博士らとの共同研究により、細胞の末端の方向から細胞を顕微鏡観察するイメージング技法を用いると、驚くべき事にTea1とTea3は末端においてドット状に存在するが、お互いのドットは必ずしも共局在しないことが分かった。また、Tea1とTea3を強制的に共局在させると、細胞の極性成長に欠陥が生じることが分かり、これらの因子は協調して働くのではなく、細胞末端で個別に機能することで細胞極性を確立していることが示された。このような、極性因子のドット状局在は、生物種を超えてみられる普遍の原理であると考えられ、細胞極性因子の局在と活性に全く新しい知見をもたらすことに成功した。

ゲノムの多様性創出と継承を連携させる微小管システムの解明

2013

Research Results Outline: 本研究では、分裂酵母の微小管形成がどのようにおこなわれるかについて研究を継続している。体細胞分裂においては、複製された染色体を2個の娘細胞に分配する 本研究では、分裂酵母の微小管形成がどのようにおこなわれるかについて研究を継続している。体細胞分裂においては、複製された染色体を2個の娘細胞に分配するために、微小管からなる紡錘体が形成され、染色体の動原体部分を左右から引っ張ることで、染色体を1:1... 本研究では、分裂酵母の微小管形成がどのようにおこなわれるかについて研究を継続している。体細胞分裂においては、複製された染色体を2個の娘細胞に分配するために、微小管からなる紡錘体が形成され、染色体の動原体部分を左右から引っ張ることで、染色体を1:1に正確に分離することができる。 紡錘体微小管形成の分子メカニズムを解明するために過去数多くの研究がおこなわれており、その成果として、多くの微小管結合タンパク質や分裂期キナーゼが必須の役割を担うことが明らかにされてきた。 しかしながら、特に紡錘体形成の初期にどのような分子が働くことが大切であるのか、既知の因子だけでは全体像に未だ到達できないのも事実であり、本研究では、分裂期の前期から中期にかけて、微小管形成に関わる因子を探索してきた。具体的には、我々がこれまで作製してきたGFP-tubulin、mCherry-核膜、CFP-中心体(SPB)の3色を発現する細胞株を作製し、これを野生型株として突然変異原処理をおこない、微小管の形態異常を示す変異体を検索するスクリーニングをおこなった。その結果、2,000を超える変異体が単離され、これを表現型ごとにクラス分けした。その中でも我々は、分裂中期以前に、微小管形成に異常を示すものに着目し、そのなかのひとつの変異体について重点的に解析を進めている。この変異体をkis1変異体と名付け、その原因遺伝子を調べたところ、未知のタンパク質をコードすることが分かった。 このkis1変異体が微小管形成のどのステップに異常を示すのかを解析したところ、前中期の紡錘体形成や、中期程度で紡錘体形成の維持に欠陥があることが分かった。 我々は、このkis1変異体では微小管形成中心であるSPBの機能に欠陥があると予想したが、これまでのところ、SPB構成因子の局在には問題が見つかっていない。これに対して、kis1変異体では、一部の動原体因子が正しく動原体に局在できていないことが分かった。これらの結果から、Kis1タンパク質は、動原体の構成維持に必須の新規因子であり、動原体の構成を介して紡錘体微小管を安定化させていると考えられる。

減数分裂においてみられる特殊な微小管の機能に迫る

2013

Research Results Outline: 当該研究では、体細胞分裂と減数分裂という目的が異なる2つの分裂様式において、細胞内の現象や分子機構がどのように異なっているのか、主に細胞骨格の微小管 当該研究では、体細胞分裂と減数分裂という目的が異なる2つの分裂様式において、細胞内の現象や分子機構がどのように異なっているのか、主に細胞骨格の微小管に焦点を当てて解析をおこなってきた。 研究をおこなうにあたり、人為的に減数分裂を誘導できる優れたモ... 当該研究では、体細胞分裂と減数分裂という目的が異なる2つの分裂様式において、細胞内の現象や分子機構がどのように異なっているのか、主に細胞骨格の微小管に焦点を当てて解析をおこなってきた。 研究をおこなうにあたり、人為的に減数分裂を誘導できる優れたモデル生物である分裂酵母を使用した。分裂酵母の微小管・動原体・中心体(SPB)をそれぞれGFP・mCherry・CFPという3つの異なる蛍光タンパク質でラベルした細胞を作製し、体細胞分裂および減数分裂を誘導することで、細胞の微小管構造がこれら2つの分裂様式においてどのように異なった挙動を示すのかが明らかになる。我々は既に、減数分裂が始まる直前に、体細胞分裂の開始前には見られない特殊な微小管構造が形成されることを発見していた。本研究では、この微小管の挙動がどのような因子によってなされているのかに焦点を当てて研究してきた。その結果、微小管結合タンパク質Dis1が、微小管の脱重合に関与する可能性が示唆された(Kakui et al. Nature Cell Biology, 2013)。 近年いくつかのグループがDis1の高等生物オーソログであるTOGタンパク質について、微小管を重合する活性があることを報告している。我々の発見は、この一般的に知られるTOGの機能とは異なり、分裂酵母の減数分裂においてはDis1/TOGが微小管を脱重合するという、全く正反対の機能を担うことを示している。そこで我々は、Dis1がどのように減数分裂微小管の脱重合を起こしているのか、主に次の2つの可能性から追究し、現在も研究を継続している。(1) Dis1が直接微小管を脱重合する可能性。(2) Dis1が何か別の因子を介して(相互作用因子などを介して)微小管を脱重合している可能性。 興味深いことに、Dis1と類似したパラログ分子であるAlp14は、他の生物におけるTOG同様に、分裂酵母の減数分裂では微小管の重合に関わるという結果を出している(同)。従って、この類似した2つの因子は、少なくとも減数分裂において、明確な機能の分離がなされていることが分かり、その原因について追及している。

微小管形成を人工的に誘導する実験系の確立 ~酵母からヒトへ~

2014

Research Results Outline:微小管は細胞骨格のひとつであり様々な細胞内現象に不可欠な役割を担う。我々は第一に,微小管が細胞内で形成される分子機構を解明することを目標としている。分微小管は細胞骨格のひとつであり様々な細胞内現象に不可欠な役割を担う。我々は第一に,微小管が細胞内で形成される分子機構を解明することを目標としている。分裂酵母をモデル生物として用いて,微小管の形成に重要な役割を担う因子を同定している。我々は次に,これ...微小管は細胞骨格のひとつであり様々な細胞内現象に不可欠な役割を担う。我々は第一に,微小管が細胞内で形成される分子機構を解明することを目標としている。分裂酵母をモデル生物として用いて,微小管の形成に重要な役割を担う因子を同定している。我々は次に,これらの因子を強制的に発現させると微小管を形成するだろうかを追求している。我々はこれらの因子を強制発現させることで,過剰な微小管を形成するか否かを検証する実験系を構築している。

休眠状態の胞子から細胞周期と細胞骨格はどのように新規形成されるのか

2014

Research Results Outline:従来の細胞周期・細胞骨格の研究は,増殖中の細胞のとある1サイクルの細胞状態に注目して解析が進められてきた。このような増殖中の細胞では,前回の細胞周期の従来の細胞周期・細胞骨格の研究は,増殖中の細胞のとある1サイクルの細胞状態に注目して解析が進められてきた。このような増殖中の細胞では,前回の細胞周期の「履歴」をもとに次の周期の分子機構が決まる。それでは,長らく休眠状態にある静止細胞は,どのように増...従来の細胞周期・細胞骨格の研究は,増殖中の細胞のとある1サイクルの細胞状態に注目して解析が進められてきた。このような増殖中の細胞では,前回の細胞周期の「履歴」をもとに次の周期の分子機構が決まる。それでは,長らく休眠状態にある静止細胞は,どのように増殖を「ゼロから」始動するのであろうか。細胞周期の始動は,細胞が周囲の環境の変化を認識して遺伝子発現システムを起動させることによると考えられるが,その分子プログラムの実態は一切明らかにされていない。また,細胞骨格や染色体の構成は,休眠状態の細胞で維持されるのか,あるいは休眠が終わり細胞周期が新生する際に,これらの骨格が新生されるのかは,不明な点が多い。 そこで本研究では,(1)分裂酵母の休眠細胞,特に胞子(配偶子)が発芽する際の遺伝子発現プロファイルを作成すること,および(2)胞子および発芽時の細胞を顕微鏡観察することで,これらのメカニズムの解明を目指した。

減数分裂における染色体交叉の意義の解明と不稔不妊性との関連

2015Collaborator:新井邦生

Research Results Outline:我々はすでに減数分裂の際に微小管が染色体配置を起こし、これによって染色体交叉の状態でも安全な染色体分配を促していることを発見してきた(Kakui et我々はすでに減数分裂の際に微小管が染色体配置を起こし、これによって染色体交叉の状態でも安全な染色体分配を促していることを発見してきた(Kakui et al. Nature Cell Biology 2013)。その際に微小管がどのように脱重合する...我々はすでに減数分裂の際に微小管が染色体配置を起こし、これによって染色体交叉の状態でも安全な染色体分配を促していることを発見してきた(Kakui et al. Nature Cell Biology 2013)。その際に微小管がどのように脱重合するかという点に焦点を当てて観察をおこなっている。その結果、当初予想されたキネシンKlp5/6ではなく、別の微小管結合タンパク質Dis1およびDam1が重要な働きをすることが分かった。現在はこれらの変異体を用いて、減数分裂特異的な微小管による染色体移動の分子原理を追究している。また、本研究では人工ミニ染色体を用いて、これが減数分裂でどのように振る舞うかも観察し、染色体の本数とそれが減数分裂に与える負担についても検証しているところである。

高齢卵子における微小管異常と不妊との関連

2017

Research Results Outline: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...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。

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

Research Results Outline: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...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。

構造クラスタ分類によるncRNA新機能の発見

2017

Research Results Outline: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...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。

Lecture Course

Course TitleSchoolYearTerm
Introduction to Bioscience A DenshibutsuriSchool of Fundamental Science and Engineering2019spring semester
Introduction to Bioscience A Kenchiku, keiei, shakou, shigenSchool of Creative Science and Engineering2019spring semester
Introduction to Bioscience B SeiiSchool of Advanced Science and Engineering2019spring semester
Science and Engineering Laboratory 1A ISchool of Fundamental Science and Engineering2019spring semester
Science and Engineering Laboratory 1A ISchool of Creative Science and Engineering2019spring semester
Science and Engineering Laboratory 1A ISchool of Advanced Science and Engineering2019spring semester
Science and Engineering Laboratory 1B ISchool of Fundamental Science and Engineering2019fall semester
Science and Engineering Laboratory 1B ISchool of Creative Science and Engineering2019fall semester
Science and Engineering Laboratory 1B ISchool of Advanced Science and Engineering2019fall semester
Introduction to Bioscience A SougoukikaiSchool of Creative Science and Engineering2019spring semester
Introduction to Bioscience A Kagaku, OukaSchool of Advanced Science and Engineering2019spring semester
Cell Biology B KagakuSchool of Advanced Science and Engineering2019fall semester
Cell Biology B Seii, OukaSchool of Advanced Science and Engineering2019spring semester
Biology LaboratorySchool of Fundamental Science and Engineering2019an intensive course(spring)
Biology LaboratorySchool of Creative Science and Engineering2019an intensive course(spring)
Biology LaboratorySchool of Advanced Science and Engineering2019an intensive course(spring)
Life Science and Medical Bio-science Seminar ISchool of Advanced Science and Engineering2019spring semester
Life Science and Medical Bio-science Seminar I [S Grade]School of Advanced Science and Engineering2019spring semester
Anatomy and Histology:LaboratorySchool of Advanced Science and Engineering2019fall semester
Anatomy and Histology:Laboratory [S Grade]School of Advanced Science and Engineering2019fall semester
Physiology BSchool of Advanced Science and Engineering2019fall semester
Physiology B [S Grade]School of Advanced Science and Engineering2019fall semester
Life Science and Medical Bioscience LaboratorySchool of Advanced Science and Engineering2019spring semester
Life Science and Medical Bio-science Laboratory ISchool of Advanced Science and Engineering2019spring semester
Life Science and Medical Bio-science Laboratory I [S Grade]School of Advanced Science and Engineering2019spring semester
Molecular Cell Biology BSchool of Advanced Science and Engineering2019spring semester
Molecular Cell Biology B [S Grade]School of Advanced Science and Engineering2019spring semester
Life Science and Medical Bio-science Seminar IISchool of Advanced Science and Engineering2019fall semester
Life Science and Medical Bio-science Seminar II [S Grade]School of Advanced Science and Engineering2019fall semester
Intermediate Life Science and Medical Bioscience LaboratorySchool of Advanced Science and Engineering2019fall semester
Life Science and Medical Bio-science Laboratory IIISchool of Advanced Science and Engineering2019fall semester
Life Science and Medical Bio-science Laboratory III [S Grade]School of Advanced Science and Engineering2019fall semester
Graduation ResearchSchool of Advanced Science and Engineering2019full year
Graduation Research [S Grade]School of Advanced Science and Engineering2019full year
Medical GeneticsSchool of Advanced Science and Engineering2019fall semester
Frontier Molecular BiologySchool of Advanced Science and Engineering2019fall quarter
Life Science and Medical Bio-science Laboratory IVSchool of Advanced Science and Engineering2019spring semester
Life Science and Medical Bio-science Laboratory VSchool of Advanced Science and Engineering2019fall semester
Cytoskeletal RegulationSchool of Advanced Science and Engineering2019fall semester
Life Science and Medical Bioscience Seminar IISchool of Advanced Science and Engineering2019spring semester
Bioscience Practicals ASchool of Advanced Science and Engineering2019fall semester
Bioscience Practicals BSchool of Advanced Science and Engineering2019spring semester
Graduation Thesis ASchool of Advanced Science and Engineering2019fall semester
Graduation Thesis BSchool of Advanced Science and Engineering2019spring semester
Current Topics in BiosciencesSchool of Advanced Science and Engineering2019fall semester
Current Topics in Biosciences [S Grade]School of Advanced Science and Engineering2019fall semester
Master's Thesis (Department of Life Science and Medical Bioscience)Graduate School of Advanced Science and Engineering2019full year
Research on Cytoskeletal LogisticsGraduate School of Advanced Science and Engineering2019full year
Research on Cytoskeletal LogisticsGraduate School of Advanced Science and Engineering2019full year
Cytoskeletal RegulationGraduate School of Advanced Science and Engineering2019fall semester
Cytoskeletal RegulationGraduate School of Advanced Science and Engineering2019fall semester
Seminar on Cytoskeletal Logistics AGraduate School of Advanced Science and Engineering2019spring semester
Seminar on Cytoskeletal Logistics AGraduate School of Advanced Science and Engineering2019spring semester
Seminar on Cytoskeletal Logistics BGraduate School of Advanced Science and Engineering2019fall semester
Seminar on Cytoskeletal Logistics BGraduate School of Advanced Science and Engineering2019fall semester
Master's Thesis (Department of Life Science and Medical Bioscience)Graduate School of Advanced Science and Engineering2019full year
Research on Cytoskeletal LogisticsGraduate School of Advanced Science and Engineering2019full year
Practical Training for Career BuildingGraduate School of Advanced Science and Engineering2019full year
Introduction of Life Science 01Global Education Center2019spring semester
Introduction of Life Science 02Global Education Center2019spring semester