Updated on 2024/03/30

写真a

 
YASUHARA,Hiroki
 
Organization
Faculty of Chemistry, Materials and Bioengineering Associate Professor
Title
Associate Professor
Contact information
メールアドレス
External link

Degree

  • 博士(理学) ( 1994.3 )

Research Areas

  • Life Science / Morphology and anatomical structure

Education

  • Osaka University   Faculty of Science   Department of Biology

    - 1988

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    Country: Japan

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  • Osaka University   Graduate School, Division of Natural Science   Physiology

    1993

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    Country: Japan

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  • Osaka University   Graduate School, Division of Natural Science   Physiology

    1993

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Professional Memberships

  • The American Society of Plant Biologists

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  • The Botanical Society of Japan

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  • Japanese Society for Plant Cell and Molecular Biology

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  • The Japanese Society of Plant Physiologists

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Papers

  • TBK11, a Tobacco Kinesin-14-II, Associates with the Nuclear Envelope through Its Central Coiled-Coil Domain Reviewed

    Hiroki Yasuhara, Kazuki Kitamoto

    Cytologia   84(3): 285-291   2019.9

  • A Kinesin-Related Protein, TBK11, Associates with the Nuclear Envelope throughout the Cell Cycle in Tobacco BY-2 Cells Reviewed

    Hiroki Yasuhara, Wataru Kurisu

    Cytologia   84(3): 277-283   2019.9

  • Displacement of the mitotic apparatuses by centrifugation reveals cortical actin organization during cytokinesis in cultured tobacco BY-2 cells

    Kengo Arima, Daisuke Tamaoki, Yoshinobu Mineyuki, Hiroki Yasuhara, Tomonori Nakai, Teruo Shimmen, Tohru Yoshihisa, Seiji Sonobe

    JOURNAL OF PLANT RESEARCH   131 ( 5 )   803 - 815   2018.9

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGER JAPAN KK  

    In plant cytokinesis, actin is thought to be crucial in cell plate guidance to the cortical division zone (CDZ), but its organization and function are not fully understood. To elucidate actin organization during cytokinesis, we employed an experimental system, in which the mitotic apparatus is displaced and separated from the CDZ by centrifugation and observed using a global-local live imaging microscope that enabled us to record behavior of actin filaments in the CDZ and the whole cell division process in parallel. In this system, returning movement of the cytokinetic apparatus in cultured-tobacco BY-2 cells occurs, and there is an advantage to observe actin organization clearly during the cytokinetic phase because more space was available between the CDZ and the distantly formed phragmoplast. Actin cables were clearly observed between the CDZ and the phragmoplast in BY-2 cells expressing GFP-fimbrin after centrifugation. Both the CDZ and the edge of the expanding phragmoplast had actin bulges. Using live-cell imaging including the global-local live imaging microscopy, we found actin filaments started to accumulate at the actin-depleted zone when cell plate expansion started even in the cell whose cell plate failed to reach the CDZ. These results suggest that specific accumulation of actin filaments at the CDZ and the appearance of actin cables between the CDZ and the phragmoplast during cell plate formation play important roles in the guidance of cell plate edges to the CDZ.

    DOI: 10.1007/s10265-018-1047-4

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  • Time-sequential observation of spindle and phragmoplast orientation in BY-2 cells with altered cortical actin microfilament patterning

    Kei H. Kojo, Hiroki Yasuhara, Seiichiro Hasezawa

    Plant Signaling and Behavior   9   e29579 - e29579   2014.6

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    Language:English   Publishing type:Research paper (scientific journal)  

    Precise division plane determination is essential for plant development. At metaphase, a dense actin microfilament meshwork appears on both sides of the cell center, forming a characteristic cortical actin microfilament twin peak pattern in BY-2 cells. We previously reported a strong correlation between altered cortical actin microfilament patterning and an oblique mitotic spindle orientation, implying that these actin microfilament twin peaks play a role in the regulation of mitotic spindle orientation. In the present study, time-sequential observation was used to reveal the progression from oblique phragmoplast to oblique cell plate orientation in cells with altered cortical actin microfilament patterning. In contrast to cells with normal actin microfilament twin peaks, oblique phragmoplast reorientation was rarely observed in cells with altered cortical actin microfilament patterning. These results support the important roles of cortical actin microfilament patterning in division plane orientation. © 2014 Landes Bioscience.

    DOI: 10.4161/psb.29579

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  • Aphidicolin-Induced Nuclear Elongation in Tobacco BY-2 cells

    Hiroki Yasuhara, Kazuki Kitamoto

    PLANT AND CELL PHYSIOLOGY   55 ( 5 )   913 - 927   2014.5

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:OXFORD UNIV PRESS  

    Plant nuclei are known to differentiate into various shapes within a single plant. However, little is known about the mechanisms of nuclear morphogenesis. We found that nuclei of tobacco BY-2 cells were highly elongated on long-term treatment with 5 mg l(-1) aphidicolin, an inhibitor of DNA polymerase alpha. In aphidicolin-treated cells, the nuclear length was correlated with the cell length. During culture in the presence of aphidicolin, the nuclei were elongated in parallel with cell elongation. Nuclear elongation was inhibited by the inhibition of cell elongation with 2,6-dichlorobenzonitrile, a cellulose synthesis inhibitor. However, cell elongation induced in the auxin-depleted medium in the absence of aphidicolin did not cause nuclear elongation, indicating that cell elongation alone is not sufficient for nuclear elongation. Treatment with either latrunculin B or propyzamide inhibited the aphidicolin-induced nuclear elongation, indicating that both actin filaments and microtubules (MTs) are required for nuclear elongation. Observations using BY-YTHCLR2 cells, in which actin filaments, MTs and nuclei were simultaneously visualized, revealed that the longitudinally arranged MT bundles associated with the nucleus play an important role in nuclear elongation, and that actin filaments affect the formation of these MT bundles. In aphidicolin-treated cells, the nuclear DNA contents of the elongated nuclei exceeded 4C, and the nuclear length was highly correlated with the nuclear DNA content. In cells treated with 50 mg l(-1) aphidicolin, cells were elongated and nucleus-associated longitudinal MT bundles were formed, but the nuclear DNA contents did not exceed 4C and the nuclei did not elongate. These results indicate that an increase in the nuclear DNA content above 4C is also required for nuclear elongation.

    DOI: 10.1093/pcp/pcu026

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  • Roles of Cortical Actin Microfilament Patterning in Division Plane Orientation in Plants

    Kei H. Kojo, Takumi Higaki, Natsumaro Kutsuna, Yuya Yoshida, Hiroki Yasuhara, Seiichiro Hasezawa

    PLANT AND CELL PHYSIOLOGY   54 ( 9 )   1491 - 1503   2013.9

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:OXFORD UNIV PRESS  

    In land plant cells, division planes are precisely predicted by the microtubule preprophase band and cortical actin microfilament pattern called the actin-depleted zone or actin microfilament twin peaks. However, the function of cortical actin microfilament patterning is not clear. In this study, we report that treatment with the inhibitor 2,3,5-triiodobenzonic acid (TIBA) or jasplakinolide increased the amount of thick actin microfilaments in tobacco BY-2 cells at interphase. However, during the division of BY-2 cells, these inhibitors did not induce visible alteration of actin microfilament thickness but altered cortical actin microfilament patterning without significant disorganization of the microtubule preprophase band. TIBA treatment induced a single intensity peak of actin microfilament distribution around the cell center, whereas jasplakinolide caused the appearance of triple peaks relative to the distribution of actin microfilament around the cell center, in approximately one-third of the cells at metaphase. Dual observations of microtubules and actin microfilaments revealed that abnormal cortical actin microfilament patterning with single or triple peaks is correlated with oblique mitotic spindles in BY-2 cells. In addition, oblique cell plates were frequently observed in BY-2 cells and Arabidopsis thaliana root cells treated with TIBA or jasplakinolide. These results provide evidence for the critical roles of cortical actin microfilament patterning in spindle and cell plate orientation.

    DOI: 10.1093/pcp/pct093

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  • Dual Observation of Microtubules and Actin Microfilaments during Cell Cycle Progression in BY-YTRF1 Cells Reviewed

    Kei H. Kojo, Hiroki Yasuhara, Nastumaro Kutsuna, Seiichiro Hasezawa

    CYTOLOGIA   78 (3) : 203-204   2013.9

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  • TMBP200, a XMAP215 homologue of tobacco BY-2 cells, has an essential role in plant mitosis

    Hiroki Yasuhara, Yuki Oe

    PROTOPLASMA   248 ( 3 )   493 - 502   2011.7

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGER WIEN  

    TMBP200 from tobacco BY-2 cells is a member of the highly conserved family of microtubule-associated proteins that includes Xenopus XMAP215, human TOGp, and Arabidopsis MOR1/GEM1. XMAP215 homologues have an essential role in spindle assembly and function in animals and yeast, but their role in plant mitosis is not fully clarified. Here, we show by immunoblot analysis that TMBP200 levels in synchronously cultured BY-2 cells increased when the cells entered mitosis, thus indicating that TMBP200 plays an important role in mitosis in tobacco. To investigate the role of TMBP200 in mitosis, we employed inducible RNA interference to silence TMBP200 expression in BY-2 cells. The resulting depletion of TMBP200 caused severe defects in bipolar spindle formation and resulted in the appearance of multinucleated cells with variable-sized nuclei. This finding indicates that TMBP200 has an essential role in bipolar spindle formation and function.

    DOI: 10.1007/s00709-010-0189-6

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  • Caffeine inhibits callose deposition in the cell plate and the depolymerization of microtubules in the central region of the phragmoplast

    H Yasuhara

    PLANT AND CELL PHYSIOLOGY   46 ( 7 )   1083 - 1092   2005.7

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:OXFORD UNIV PRESS  

    Treatment of tobacco BY-2 cells with 10 mM caffeine that was started after the cells had entered the mitotic phase did not completely inhibit the deposition of callose in the cell plate and allowed the centrifugal redistribution of phragmoplast microtubules. On the other hand, when treatment with caffeine was started before the cells entered the mitotic phase, the deposition of callose was completely inhibited and the redistribution of phragmoplast microtubules was also inhibited. As the inhibition of redistribution of phragmoplast microtubules seems to be caused by the inhibition of depolymerization of microtubules at the central region of the phragmoplast, these results strongly suggest that the deposition of callose in the cell plate is tightly linked with the depolymerization of phragmoplast microtubules. Callose deposition was observed in phragmoplasts isolated from caffeine-treated cells as well as in those isolated from non-caffeine-treated cells, and caffeine did not inhibit callose synthesis in isolated phragmoplast, indicating that caffeine neither inhibits the accumulation of callose synthase at the equatorial regions of the phragmoplast nor arrests callose synthase itself.

    DOI: 10.1093/pcp/pci121

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  • Cell plate formation: knowledge from studies using tobacco BY-2 cells. Reviewed

    YASUHARA Hiroki, Tetsuhiro Asada

    In Nagata T et al. (ed.): ”Tobacco BY-2 cell”. Biotechnology in Agriculture and Forestry.Springer-Verlag, Berlin, Heidelberg, New York, Tokyo   pp116-131   2004

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  • The Phragmoplast; its Development and Function

    YASUHARA Hiroki

    pp.92-103   2000.10

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  • Inhibition of cell-plate formation by brefeldin A inhibited the depolymerization of microtubules in the central region of the phragmoplast

    H Yasuhara, H Shibaoka

    PLANT AND CELL PHYSIOLOGY   41 ( 3 )   300 - 310   2000.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPANESE SOC PLANT PHYSIOLOGISTS  

    Treatment of tobacco BY-2 cells with 20 mu M brefeldin A (BFA), which causes disassembly of the Golgi apparatus (Yasuhara et al. 1995), completely inhibited the formation of the cell plate when the treatment was started before the chromosomes had begun to to condense, In cells in which cell-plate formation was inhibited by BFA, the centrifugal development of the phragmoplast was also inhibited. In such cells, the depolymerization of microtubules in the central region of the phragmoplast did not occur at least for Ih after the formation of the phragmoplast, while the centrifugal development of the phragmoplast and cell-plate formation were completed in almost all cells not treated with BFA. The inhibition of cell-plate formation seems to inhibit the centrifugal development of the phragmoplast by inhibiting the depolymerization of microtubules in the central region of the phragmoplast, which is required for the supply of free tubulin necessary for the polymerization of microtubules at the outer margins of the phragmoplast.

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  • Effects of brefeldin A on the formation of cell plate in tobacco BY-2 cells,European Journal of Cell Biology 66

    Hiroki Yasuhara, Seiji Sonobe, Hiroh Shibaoka

    274頁-281頁   1995

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  • Effects of taxol on the development of the cell plate and of the phragmoplast in tobacco BY-2 cells,Plant and Cell Physiology 34(1) Reviewed

    YASUHARA Hiroki, Sonobe Seiji, Shibaoka Hiroh

    21頁-29頁   1993

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Books

  • Effects of brefeldin A on the formation of cell plate in tobacco BY-2 cells, European Journal of Cell Biology 66

    YASUHARA Hiroki( Role: Joint author)

    1995 

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  • Effects of taxol on the development of the cell plate and of the phragmoplast in tobacco BY-2 cells, Plant and Cell Physiology 34(1)

    YASUHARA Hiroki( Role: Joint author)

    1993 

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  • 植物細胞における細胞質分裂の機構

    安原 裕紀( Role: Sole author)

    『技苑』 

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  • 細胞質分裂における細胞骨格の働き

    安原 裕紀( Role: Joint author)

    『遺伝』 47(11) 

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  • フラグモプラスト研究の最近の話題

    安原 裕紀( Role: Joint author)

    『植物細胞工学』 5 (6) 

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  • Effects of Brefeldin A (BFA) on cell plate formation in tobacco BY-2 cells, XV International Botanical Congress, Yokohama, Japan

    YASUHARA Hiroki

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MISC

Presentations

  • タバコ培養細胞 BY-2 のキネシン 14-II,TBK11の機能解析 TBK11 の機能解析

    安原 裕紀, 栗栖 渉, 北本 一輝

    日本植物形態学会  2019.9 

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    Event date: 2019.9

    Venue:東北大学川内北キャンパス  

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  • タバコBY-2細胞におけるYFP融合タンパク質の発現によるカロース合成酵素の可視化の試み

    安原 裕紀, 堂段 祐貴, 中林 音奈, 木下 優

    日本植物形態学会  2018.9 

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    Event date: 2018.9

    Venue:広島県情報プラザ  

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  • Involvement of M phase-specific kinesin NACK1 in interacellular transport during the formation of cell plates

    Michiko Sasabe, Takumi Higaki, Yuka Nishida, Shimon Morioka, Reina Suzuki, Tomohiro Uemura, Hiroki Yasuhara, Seiichiro Hasezawa, Takashi Ueda, Yasunori Machida

    2018.3 

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    Event date: 2018.3

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  • キネシン様タンパク質PAKRP2はフラグモプラスト赤道面の逆平行微小管領域の長さを調節する

    安原 裕紀

    日本植物学会  2016.9 

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    Event date: 2016.9

    Venue:沖縄コンベンションセンター  

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  • A role of phragmoplast associated kinesin NtPAKRP2 in tobacco BY-2 cells

    YASUHARA,Hiroki, Inoue, Maimi, Yata, Masatoshi, Oonishi, Natsuka, Nakafunai, Maiko, Nakai, Eita, Yoshimoto, Satoshi

    2016.3 

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    Event date: 2016.3

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  • タバコBY-2細胞のフラグモプラスト形成におけるPAKRP2とMAP65-3の役割

    安原 裕紀, 井上 真以美, 矢田 昌敏, 大西 夏佳, 上野 翠, 仲舟井 舞子, 中井 英太, 吉本 智

    日本植物学会  2015.9 

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    Event date: 2015.9

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  • タバコBY-2細胞のフラグモプラスト局在キネシンの解析

    安原 裕紀, 井上 真以美, 矢田 昌敏, 大西 夏佳

    日本植物学会第78回大会  2014.9 

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    Event date: 2014.9

    Venue:明治大学 生田キャンパス(神奈川県)  

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  • 細胞分裂における表層アクチン繊維および細胞分裂面形成の経時観察

    湖城 恵, 桧垣 匠, 朽名 夏麿, 馳澤 盛一郎

    日本植物生理学会  2014.3 

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    Event date: 2014.3

    Venue:富山大学 五福キャンパス  

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  • タバコBY-2細胞におけるアフィディコリン処理により誘導される核の伸長の機構

    安原裕紀, 北本一輝

    日本植物学会  2013.9 

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    Event date: 2013.9

    Venue:北海道大学 札幌キャンパス  

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  • Aphidicolin-induced nuclear elongation in tobacco BY-2

    Hiroki Yasuhara, Kazuki Kitamoto

    2013.3 

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    Event date: 2013.3

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  • タバコBY-2細胞におけるアフィディコリン処理による核の過伸長

    北本一輝, 安原 裕紀

    日本植物学会  2012.9 

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    Event date: 2012.9

    Venue:兵庫県立大学 姫路書写キャンパス  

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  • 細胞周期における微小管ダイナミクスの変動はTMBP200のタンパク質量と関連するか?

    松本英泰 (B), 渡辺香苗 (B), 田端清治 (B), 安原裕紀

    第53回日本植物生理学会年会  2012.3 

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    Event date: 2012.3

    Venue:京都  

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  • タバコBY-2における核表面に局在するキネシン様タンパク質NMK1の機能解析

    安原裕紀, 川本怜奈 (B), 榊本満里奈 (B), 宮本怜 (B), 北本一輝 (B), 光武翔 (B), 浅田哲弘(大阪大学)

    日本植物学会第75回大会  2011.9 

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    Event date: 2011.9

    Venue:東京  

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  • タバコBY-2細胞における核表面に局在するキネシンNMK-1の機能解析

    安原 裕紀, 川本 怜奈 (B), 榊本 満里奈 (B), 宮本 怜 (B), 北本 一輝 (B), 光武 翔 (B), 浅田 哲弘(大阪大学)

    日本植物生理学会  2011.3 

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    Event date: 2011.3

    Venue:東北大学 川内北キャンパス  

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  • タバコBY-2細胞のCHドメインを持つキネシン様タンパク質、TBK1、TBK2、TBK9の機能解析

    安原 裕紀, 川本 怜奈 (B), 榊本 満里奈 (B), 宮本 怜 (B), 濱下 知子 (B), 光武 翔 (B), 浅田 哲弘(大阪大学)

    日本植物学会  2010.9 

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    Event date: 2010.9

    Venue:中部大学 春日井キャンパス  

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  • タバコ培養細胞BY-2のキネシン様タンパク質TBK1、TBK7、TBK11の細胞内局在

    川本 怜奈 (B), 浅田 哲弘(大阪大学), 安原 裕紀

    日本植物学会  2009.9 

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    Event date: 2009.9

    Venue:山形大学小白川キャンパス  

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  • タバコ培養細胞BY-2のXMAP215ホモローグTMBP200の機能ドメインの解析

    安原 裕紀, 小西 麻由 (B), 松永幸大(大阪大学), 栗原大輔(大阪大学)

    日本植物学会第72回大会研究発表記録  2008.9 

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  • 懸濁培養細胞と転写誘導系を用いた陸上植物特異的キネシン、TBK5の局在傾向の解析

    浅田哲弘(大阪大学), 大津寄 佑香 (B), 安原 裕紀

    日本植物学会  2008.9 

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    Event date: 2008.9

    Venue:高知大学朝倉キャンパス  

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  • TMBP200の微小管結合ドメイン

    安原 裕紀, 小西 麻由 (B), 磯部 靖夫 (B)

    日本植物生理学会  2008.3 

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    Event date: 2008.3

    Venue:札幌コンベンションセンター  

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  • タバコBY-2細胞におけるRNAiによるTMBP200の発現抑制がプロトプラスト由来細胞の伸長に及ぼす効果

    安原 裕紀

    日本植物生理学会  2007.3 

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    Event date: 2007.3 - 2008.3

    Venue:愛媛大学城北キャンパス  

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  • タバコBY-2細胞におけるGFP-TMBP200融合タンパク質の発現

    安原 裕紀, 大江祐樹

    第47回日本植物生理学会年会要旨集  2006 

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    Event date: 2006

    科研費若手研究B 20030401-20060331

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  • タバコBY-2細胞におけるRNAiを用いたTMBP200の発現抑制

    安原 裕紀, 大江祐樹

    日本植物学会  2006 

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    Event date: 2006

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  • シュート原基集塊を形成するシロイヌナズナのmsp変異体とサイトカイニン情報伝達

    安原 裕紀, 宇都宮由恵

    日本植物生理学会  2005.3 

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    Event date: 2005.3

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  • フォトブリーチ法を用いたフラグモプラスト微小管の動態解析

    安原 裕紀, 浅田哲弘, 祐村恵彦

    第46回日本植物学会年会講演要旨集  2005.3 

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  • タバコBY-2細胞におけるGFPとTMBP200部分断片の融合タンパク質の発現による細胞質分裂阻害

    安原 裕紀, 作田宏平, 伊藤大貴, 三谷和夫, 鶴来隆幸

    日本植物学会第68回大会研究発表記録  2004.9 

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  • シュート原基の集塊を形成するシロイヌナズナの温度感受性変異体の単離

    安原 裕紀, 上田佳代, 岩田英治, 松田光博

    日本植物学会  2003.9 

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  • YFP-tubulinを発現するBY-2細胞における細胞板のカロースの蓄積とフラグモプラスト微小管の分布変化

    安原 裕紀, 廣井良伸, 作田宏平

    日本植物生理学会  2003.3 

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  • タバコ培養細胞BY-2の微小管束化タンパク質TMBP200のcDNAクローニングと細胞内局在

    安原 裕紀, 村岡正明, 正垣宏樹, 森仁志

    日本植物生理学会  2001.3 

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    科研費奨励研究

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  • タバコ培養細胞BY-2より単離したフラグモプラストへのCa2+の取り込み

    安原 裕紀

    日本植物学会第61回大会 

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  • Effects of Brefeldin A (BFA) on cell plate formation in tobacco BY-2 cells,XV International Botanical Congress, Yokohama,Japan

    YASUHARA Hiroki, Seiji Sonobe, Hiroh SHibaoka

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  • フラグモプラストの遠心的発達に対する細胞板形成の関与

    安原 裕紀

    日本植物学会第60会大会 

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  • 分裂終期のタバコ培養細胞BY-2より単離した微小管束化因子

    安原 裕紀

    日本植物学会第58会大会 

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Research Projects

  • Mechanisms of the centrifugal development of the phragmoplast in higher plant cells

    Grant number:18570051  2006 - 2008

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    YASUHARA Hiroki, ASADA Tetsuhiro

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    Grant amount:\3990000 ( Direct Cost: \3600000 、 Indirect Cost:\390000 )

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  • 植物細胞の細胞質分裂における微小管束化タンパク質TMBP200の機能解析

    Grant number:15770033  2003 - 2005

    日本学術振興会  科学研究費助成事業  若手研究(B)

    安原 裕紀

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    Grant amount:\3600000 ( Direct Cost: \3600000 )

    TMBP200の全長とGFPの融合タンパク質を誘導発現するBY-2細胞を作出し、さらにこの形質転換株に35Sp::mRFP-βチューブリンcDNAを導入し、微小管も可視化された株を作出した。GFP-TMBP200は、間期の細胞では細胞質全体と、一部の細胞では表層微小管に局在し、分裂期の細胞では、紡錘体とフラグモプラストに局在した。また、GFP-TMBP200の誘導発現により、高頻度で、不均一な大きさの多数の核を持つ細胞が出現した。この多核細胞は、微小管破壊剤処理による有糸分裂阻害でみられるものとよく似ていた。GFP-TMBP200の発現による微小管の脱重合は観察されなかったが、異常な形態の紡錘体が観察されたことから、GFP-TMBP200の誘導発現により微小管の脱重合とは異なる機構で紡錘体の機能が阻害されたと考えられる。この結果は、TMBP200が、有糸分裂において重要な役割を果たすことを示唆するものである。このことを確かめるために、TMBP200に特異的な2本鎖RNAの転写誘導のためコンストラクトを構築し、これをBY-2細胞に導入して、TMBP200の発現抑制を試みたところ、2本鎖RNAの転写誘導時にのみTMBP200の発現が強く抑えられる株を取得することが出来た。これらの株では、TMBP200の発現抑制により高頻度で有糸分裂が阻害された。現在これらの株に35Sp::mRFP-βチューブリンcDNAを導入し、TMBP200の発現抑制により微小管構造がどの様に変化するかを検討している。

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  • IDENTIFICATION OF THE MICROTUBULE MOTOR FOR THE TRANSPORT OF CELL PLATE MATERIALS

    Grant number:13640647  2001 - 2002

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    ASADA Tetsuhiro, YASUHARA Hiroki

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    Grant amount:\3500000 ( Direct Cost: \3500000 )

    Cells of higher plants are able to generate microtubule arrays that differ in architecture from those generaled in animal and fungal cells and that mediate higher plant-specific processes in cell division or morphogenesis. Although 1itt1e is known about the molecular basis of these abilities, comparative analyses of morphologies and ultrastructurcs of microtubule arrays predict that molecules involved in microtubule organization in higher plant cells might be, at leant in part, distinct from those in animal or fungal cells. In an attempt to understand the essential mechanisms for generating higher plant specific microtubule arrays, we characterize a higher plant-specific kinesin subtype, TBK5. Experiments in which TBK5 was overproduced in tobacco BY-2 cells showed that accumulated TBK5 can induce remarkable and characteristic changes in microtubule arrangements. Furthermore, immunofluorescence study using antibodies against recombinant TBK5 polypeptides showed that endogenous TBK5 proteins are not distributed along the length of microtubules. We currently explore the possibility shat the TBK5 kinesin subtype might be a component of microlubule-nucleating units playing a key role in the centrosome-independenl microtubule organization.

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  • 分裂終期のタバコBY-2細胞より単離した190-KDaMAPの機能解析

    Grant number:08740626  1996

    日本学術振興会  科学研究費助成事業  奨励研究(A)

    安原 裕紀

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    Grant amount:\1000000 ( Direct Cost: \1000000 )

    SDS-PAGE後PVDF膜にブロットして切り出した190-KDaMAPをBrCNにより部分分解し、得られたペプチド断片をSDS-PAGEで分離後、PVD膜にブロットした。幾つかのバンドを切り出し、ペプチドシークエンサーによってアミノ酸配列を調べた。これにより、それぞれ23、20、16、13残基の長さに4箇所のアミノ酸配列を解読する事ができた。検索の結果、得られた配列はいずれも、既知の配列との相同性が低かったため、190-kDaMAPが全く未知のタンパク質である可能性が考えられた。アミノ酸配列の情報を基に、対応するcDNAの配列を予想し、縮重が小さくなる部分を選んで、PCRのための縮重プライマーをセンスプライマーとアンチセンスプライマーを合わせて14通り合成した。PCRのための鋳型DNAとして、アフィディコリンを用いて細胞周期をG2期から前期に同調化したBY-2細胞よりSDS-LiCl法により単離した全RNAを、ポリTカラムで精製して得たmRNAからAMV逆転写酵素を用いて合成したものを用いた。作成したプライマーの意味のあるすべての組み合わせについて、TaKaRaLATaqを用いてPCRを行ったところ、多くの組み合わせにおいて、複数の産物の増幅が見られたが、幾つかの組み合わせにおいて特異的と思われる産物が増幅されたため、現在これらをTAクローンニングし塩基配列の解読を行っている。また、一箇所の部分アミノ酸配列から、二つ作成したプライマーを用いて、nested PCRによる増幅も試みている。

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  • 分裂終期のタバコ培養細胞BY-2より単離した190-kDa MAPの研究

    Grant number:06740608  1994

    日本学術振興会  科学研究費助成事業  奨励研究(A)

    安原 裕紀

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    Grant amount:\900000 ( Direct Cost: \900000 )

    細胞周期を分裂終期に同調化したタバコ培養細胞BY-2より得たミニプロトプラストから微小管を調製し、この微小管から、300mM KCl処理によって、190-kDa MAPを含む粗抽出分画を得、これをFPLC-Mono Sカラムにより精製した。この精製した190-kDa MAPをウシの脳由来のMAPを含まない微小管と、インキュベートした後、固定、包埋し、その切片を電子顕微鏡観察したところ、微小管と微小管を架橋するおよそ10nmの構造が認められ、この構造が190-kDa MAPであると考えられた。また、190-kDa MAPは、Mono-Sカラムによる精製段階で、収率が、甚だしく減少したため、この精製190-kDa MAPを抗原とした抗体の作成は諦め、190-kDa MAPの部分的なアミノ酸配列の決定に重点を置いた。
    190-kDa MAPを 含む粗抽出分画をSDS-PAGEにかけたのち、PVDF膜にブロットしCBB染色を行い、目的のバンドを切り出して、アミノ酸シークエンサーにかけたところ、十分な量の蛋白を用いたにも関わらず、PTHアミノ酸の信号が得られず、190-kDa MAPのN末はブロックされているものと判断した。そこで190-kDa MAPを移したPVDF膜をブロテアーゼで処理し分解を試みた。6種類のブロテアーゼを検討したが、いずれも良好でなかったため、CNBrによる分解を行った。分解処理したものを再びSDS-PAGEにかけ、PVDF膜にブロットし、CBB染色をしたところ、分解処理の収率は低かったが、いくつかのバンドが認められた。これを、アミノ酸シークエンサーにかけたが、ペプチドの量が不十分であったため、PTHアミノ酸の信号が弱く、その配列を決定するには至っていない。現在、十分量のペプチドを用いてアミノ酸配列を決定する努力を継続している。

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Devising educational methods

  • 学生実験において、顕微鏡画像共有システムを導入し、各受講者の観察している顕微鏡画像の教卓での確認や特定の学生の観察像の全員への配信などが出来るようにした。これにより、受講者の理解度が飛躍的に高まった。

Teaching materials

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Teaching method presentations

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Special notes on other educational activities

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