2022/06/28 更新

写真a

トミナガ モトキ
富永 基樹
所属
教育・総合科学学術院 教育学部
職名
教授

兼担

  • 理工学術院   大学院先進理工学研究科

学内研究所等

  • 2020年
    -
    2022年

    理工学術院総合研究所   兼任研究員

学歴

  •  
    -
    2000年

    姫路工業大学   理学研究科   生命科学専攻  

  •  
    -
    1995年

    姫路工業大学   理学部   生命科学科  

  •  
    -
    1995年

    姫路工業大学   理学部   生命科学科  

学位

  • 姫路工業大学   理学(博士)

経歴

  • 2017年04月
    -
     

    早稲田大学   教育・総合科学学術院   准教授

  • 2014年09月
    -
    2017年03月

    早稲田大学   教育・総合科学学術院   専任講師

  • 2011年10月
    -
    2015年03月

    科学技術振興機構   さきがけ   さきがけ研究者 兼任

  • 2011年10月
    -
    2015年03月

    科学技術振興機構   さきがけ   さきがけ研究者 兼任

  • 2012年09月
    -
    2014年09月

    理化学研究所   きぼう船内実験チーム   兼務

  • 2008年04月
    -
    2014年09月

    理化学研究所   基幹研究所   専任研究員

  • 2007年10月
    -
    2008年03月

    理化学研究所   和光中央研究所   研究員

  • 2006年01月
    -
    2007年09月

    東京大学   医科学研究所   特任助教

  • 2003年01月
    -
    2005年12月

    独立行政法人通信総合研究所   関西先端研究センター   日本学術振興会 特別研究員

  • 2000年04月
    -
    2002年12月

    郵政省通信総合研究所   関西先端研究センター   専攻研究員

▼全件表示

所属学協会

  •  
     
     

    日本植物学会

  •  
     
     

    日本植物生理学会

  •  
     
     

    日本細胞生物学会

  •  
     
     

    日本生物物理学会

 

研究分野

  • 植物分子、生理科学

研究キーワード

  • 分子生物学

  • 植物生理学

  • 細胞生物学

論文

  • Heterologous transformation of Camelina sativa with high-speed chimeric myosin XI-2 promotes plant growth and leads toincreased seed yield.

    Zhongrui Duan, Kohji Ito, Motoki Tominaga

    Plant Biotechnology   37 ( 3 ) 253 - 259  2020年09月  [査読有り]  [招待有り]

    DOI

  • Characterization of ancestral myosin XI from Marchantia polymorpha by heterologous expression in Arabidopsis thaliana.

    Zhongrui Duan, Misato Tanaka, Takehiko Kanazawa, Takeshi Haraguchi, AkikoTakyu, Atsuko Era, Takashi Ueda, Kohji Ito, Motoki Tominaga

    The Plant Journal   104   460 - 473  2020年07月  [査読有り]  [招待有り]

  • Diversity of Plant Actin–Myosin Systems

    Takeshi Haraguchi, Zhongrui Duan, Masanori Tamanaha, Kohji Ito, MotokiTominaga

    Springer Book "The Cytoskeleton Diverse Roles in a Plant’s Life"   24   49 - 61  2019年12月  [査読有り]  [招待有り]

  • Functional Diversity of Class XI Myosins in Arabidopsis thaliana.

    Takeshi Haraguchi, Kohji Ito, Zhongrui Duan, Sarula, Kento Takahashi, Yuno Shibuya, Nanako Hagino, Yuko Miyatake, Akihiko Nakano, Motoki Tominaga

    Plant Cell Physiol.   59   2268 - 2277  2018年11月  [査読有り]  [招待有り]

  • Measurement of enzymatic and motile activities of Arabidopsis myosins by using Arabidopsis actins

    Sa Rula, Takahiro Suwa, Saku T. Kijima, Takeshi Haraguchi, Shinryu Wakatsuki, Naruki Sato, Zhongrui Duan, Motoki Tominaga, Taro Q.P. Uyeda, Kohji Ito

    Biochemical and Biophysical Research Communications   495 ( 3 ) 2145 - 2151  2018年01月  [招待有り]

     概要を見る

    There are two classes of myosin, XI and VIII, in higher plants. Myosin XI moves actin filaments at high speed and its enzyme activity is also very high. In contrast, myosin VIII moves actin filaments very slowly with very low enzyme activity. Because most of these enzymatic and motile activities were measured using animal skeletal muscle α-actin, but not plant actin, they would not accurately reflect the actual activities in plant cells. We thus measured enzymatic and motile activities of the motor domains of two Arabidopsis myosin XI isoforms (MYA2, XI-B), and one Arabidopsis myosin VIII isoform (ATM1), by using three Arabidopsis actin isoforms (ACT1, ACT2, and ACT7). The measured activities were different from those measured by using muscle actin. Moreover, Arabidopsis myosins showed different enzymatic and motile activities when using different Arabidopsis actin isoforms. Our results suggest that plant actin should be used for measuring enzymatic and motile activities of plant myosins and that different actin isoforms in plant cells might function as different tracks along which affinities and velocities of each myosin isoform are modulated.

    DOI PubMed

  • Actin-myosin XI: An intracellular control network in plants

    Duan, Zhongrui, Tominaga, Motoki

    Biochemical and Biophysical Research Communications    2018年01月  [招待有り]

     概要を見る

    © 2018 The Authors. Actin is one of the three major cytoskeletal components in eukaryotic cells. Myosin XI is an actin-based motor protein in plant cells. Organelles are attached to myosin XI and translocated along the actin filaments. This dynamic actin-myosin XI system plays a major role in subcellular organelle transport and cytoplasmic streaming. Previous studies have revealed that myosin-driven transport and the actin cytoskeleton play essential roles in plant cell growth. Recent data have indicated that the actin-myosin XI cytoskeleton is essential for not only cell growth but also reproductive processes and responses to the environment. In this review, we have summarized previous reports regarding the role of the actin-myosin XI cytoskeleton in cytoplasmic streaming and plant development and recent advances in the understanding of the functions of actin-myosin XI cytoskeleton in Arabidopsis thaliana.

    DOI

  • 原形質流動を操るバイオマス増産技術

    段中瑞, 富永基樹

    化学工業   68   56 - 60  2017年

  • Myosin XI-I is Mechanically and Enzymatically Unique Among Class-XI Myosins in Arabidopsis

    Takeshi Haraguchi, Motoki Tominaga, Akihiko Nakano, Keiichi Yamamoto, Kohji Ito

    PLANT AND CELL PHYSIOLOGY   57 ( 8 ) 1732 - 1743  2016年08月  [査読有り]  [招待有り]

     概要を見る

    Arabidopsis possesses 13 genes encoding class-XI myosins. Among these, myosin XI-I is phylogenetically distant. To examine the molecular properties of Arabidopsis thaliana myosin XI-I (At myosin XI-I), we performed in vitro mechanical and enzymatic analyses using recombinant constructs of At myosin XI-I. Unlike other biochemically studied class-XI myosins, At myosin XI-I showed extremely low actinactivated ATPase activity (V-max = 3.7 Pi s(-1) head(-1)). The actin-sliding velocity of At myosin XI-I was 0.25 mu m s(-1), >10 times lower than those of other class-XI myosins. The ADP dissociation rate from acto-At myosin XI-I was 17 s(-1), accounting for the low actin-sliding velocity. In contrast, the apparent affinity for actin in the presence of ATP, estimated from Kapp (0.61 mu M) of actin-activated ATPase, was extremely high. The equilibrium dissociation constant for actin was very low in both the presence and absence of ATP, indicating a high affinity for actin. To examine At myosin XI-I motility in vivo, green fluorescent protein-fused full-length At myosin XI-I was expressed in cultured Arabidopsis cells. At myosin XI-I localized not only on the nuclear envelope but also on small dots moving slowly (0.23 mu m s(-1)) along actin filaments. Our results show that the properties of At myosin XI-I differ from those of other Arabidopsis class-XI myosins. The data suggest that At myosin XI-I does not function as a driving force for cytoplasmic streaming but regulates the organelle velocity, supports processive organelle movement or acts as a tension generator.

    DOI

  • The molecular mechanism and physiological role of cytoplasmic streaming

    Motoki Tominaga, Kohji Ito

    Current Opinion in Plant Biology   27   104 - 110  2015年10月

    担当区分:筆頭著者, 責任著者

     概要を見る

    Cytoplasmic streaming occurs widely in plants ranging from algae to angiosperms. However, the molecular mechanism and physiological role of cytoplasmic streaming have long remained unelucidated. Recent molecular genetic approaches have identified specific myosin members (XI-2 and XI-K as major and XI-1, XI-B, and XI-I as minor motive forces) for the generation of cytoplasmic streaming among 13 myosin XIs in Arabidopsis thaliana. Simultaneous knockout of these myosin XI members led to a reduced velocity of cytoplasmic streaming and marked defects of plant development. Furthermore, the artificial modifications of myosin XI-2 velocity changed plant and cell sizes along with the velocity of cytoplasmic streaming. Therefore, we assume that cytoplasmic streaming is one of the key regulators in determining plant size.

    DOI

  • 原形質流動による成長制御から考える植物の光戦略

    富永基樹

    光合成研究   25 ( 1 ) 42 - 47  2015年04月  [招待有り]

  • Kinetic mechanism of Nicotiana tabacum myosin-11 defines a new type of a processive motor

    Ralph P. Diensthuber, Motoki Tominaga, Matthias Preller, Falk K. Hartmann, Hidefumi Orii, Igor Chizhov, Kazuhiro Oiwa, Georgios Tsiavaliaris

    FASEB JOURNAL   29 ( 1 ) 81 - 94  2015年01月  [査読有り]  [招待有り]

     概要を見る

    The 175-kDa myosin-11 from Nicotiana tabacum (Nt(175kDa)myosin-11) is exceptional in its mechanical activity as it is the fastest known processive actin-based motor, moving 10 times faster than the structurally related class 5 myosins. Although this ability might be essential for long-range organelle transport within larger plant cells, the kinetic features underlying the fast processive movement of Nt(175kDa)myosin-11 still remain unexplored. To address this, we generated a single-headed motor domain construct and carried out a detailed kinetic analysis. The data demonstrate that Nt(175kDa)myosin-11 is a highduty ratio motor, which remains associated with actin most of its enzymatic cycle. However, different from other processive myosins that establish a high duty ratio on the basis of a rate-limiting ADP-release step, Nt(175kDa)myosin-11 achieves a high duty ratio by a prolonged duration of the ATP-induced isomerization of the actin-bound states and ADP release kinetics, both of which in terms of the corresponding time constants approach the total ATPase cycle time. Molecular modeling predicts that variations in the charge distribution of the actin binding interface might contribute to the thermodynamic fine-tuning of the kinetics of this myosin. Our study unravels a new type of a high duty ratio motor and provides important insights into the molecular mechanism of processive movement of higher plant myosins.

    DOI

  • Molecular Characterization and Subcellular Localization of Arabidopsis Class VIII Myosin, ATM1

    Takeshi Haraguchi, Motoki Tominaga, Rie Matsumoto, Kei Sato, Akihiko Nakano, Keiichi Yamamoto, Kohji Ito

    JOURNAL OF BIOLOGICAL CHEMISTRY   289 ( 18 ) 12343 - 12355  2014年05月  [査読有り]  [招待有り]

     概要を見る

    Background: Molecular properties of class VIII myosin are not characterized. Results:Arabidopsis class VIII myosin, ATM1, has low enzymatic activity and high affinity for actin and is primarily localized at the cell cortex. Conclusion: Our data suggest that ATM1 functions as a tension sensor/generator. Significance: This is the first report of enzymatic and motile properties of class VIII myosin.
    Land plants possess myosin classes VIII and XI. Although some information is available on the molecular properties of class XI myosins, class VIII myosins are not characterized. Here, we report the first analysis of the enzymatic properties of class VIII myosin. The motor domain of Arabidopsis class VIII myosin, ATM1 (ATM1-MD), and the motor domain plus one IQ motif (ATM1-1IQ) were expressed in a baculovirus system and characterized. ATM1-MD and ATM1-1IQ had low actin-activated Mg2+-ATPase activity (V-max = 4 s(-1)), although their affinities for actin were high (K-actin = 4 m). The actin-sliding velocities of ATM1-MD and ATM1-1IQ were 0.02 and 0.089 m/s, respectively, from which the value for full-length ATM1 is calculated to be approximate to 0.2 m/s. The results of actin co-sedimentation assay showed that the duty ratio of ATM1 was approximate to 90%. ADP dissociation from the actinATM1 complex (acto-ATM1) was extremely slow, which accounts for the low actin-sliding velocity, low actin-activated ATPase activity, and high duty ratio. The rate of ADP dissociation from acto-ATM1 was markedly biphasic with fast and slow phase rates (5.1 and 0.41 s(-1), respectively). Physiological concentrations of free Mg2+ modulated actin-sliding velocity and actin-activated ATPase activity by changing the rate of ADP dissociation from acto-ATM1. GFP-fused full-length ATM1 expressed in Arabidopsis was localized to plasmodesmata, plastids, newly formed cell walls, and actin filaments at the cell cortex. Our results suggest that ATM1 functions as a tension sensor/generator at the cell cortex and other structures in Arabidopsis.

    DOI

  • 植物の大きさはミオシンモーターのスピードで決まる!

    富永 基樹, 伊藤 光二

    生物物理   54 ( 5 ) 259 - 261  2014年  [招待有り]

    CiNii

  • Cytoplasmic Streaming Velocity as a Plant Size Determinant

    Motoki Tominaga, Atsushi Kimura, Etsuo Yokota, Takeshi Haraguchi, Teruo Shimmen, Keiichi Yamamoto, Akihiko Nakano, Kohji Ito

    DEVELOPMENTAL CELL   27 ( 3 ) 345 - 352  2013年11月  [査読有り]  [招待有り]

     概要を見る

    Cytoplasmic streaming is active transport widely occurring in plant cells ranging from algae to angiosperms. Although it has been revealed that cytoplasmic streaming is generated by organelle-associated myosin XI moving along actin bundles, the fundamental function in plants remains unclear. We generated high- and low-speed chimeric myosin XI by replacing the motor domains of Arabidopsis thaliana myosin XI-2 with those of Chara corallina myosin XI and Homo sapiens myosin Vb, respectively. Surprisingly, the plant sizes of the transgenic Arabidopsis expressing high- and low-speed chimeric myosin XI-2 were larger and smaller, respectively, than that of the wild-type plant. This size change correlated with acceleration and deceleration, respectively, of cytoplasmic streaming. Our results strongly suggest that cytoplasmic streaming is a key determinant of plant size. Furthermore, because cytoplasmic streaming is a common system for intracellular transport in plants, our system could have applications in artificial size control in plants.

    DOI PubMed

  • Calcium-induced Mechanical Change in the Neck Domain Alters the Activity of Plant Myosin XI

    Motoki Tominaga, Hiroaki Kojima, Etsuo Yokota, Rinna Nakamori, Michael Anson, Teruo Shimmen, Kazuhiro Oiwa

    JOURNAL OF BIOLOGICAL CHEMISTRY   287 ( 36 ) 30711 - 30718  2012年08月  [査読有り]  [招待有り]

     概要を見る

    Plant myosin XI functions as a motor that generates cytoplasmic streaming in plant cells. Although cytoplasmic streaming is known to be regulated by intracellular Ca2+ concentration, the molecular mechanism underlying this control is not fully understood. Here, we investigated the mechanism of regulation of myosin XI by Ca2+ at the molecular level. Actin filaments were easily detached from myosin XI in an in vitro motility assay at high Ca2+ concentration (pCa 4) concomitant with the detachment of calmodulin light chains from the neck domains. Electron microscopic observations showed that myosin XI at pCa 4 shortened the neck domain by 30%. Single-molecule analysis revealed that the step size of myosin XI at pCa 4 was shortened to 27 nm under low load and to 22 nm under high load compared with 35 nm independent of the load for intact myosin XI. These results indicate that modulation of the mechanical properties of the neck domain is a key factor for achieving the Ca2+-induced regulation of cytoplasmic streaming.

    DOI PubMed

  • RNA Processing Bodies, Peroxisomes, Golgi Bodies, Mitochondria, and Endoplasmic Reticulum Tubule Junctions Frequently Pause at Cortical Microtubules

    Takahiro Hamada, Motoki Tominaga, Takashi Fukaya, Masayoshi Nakamura, Akihiko Nakano, Yuichiro Watanabe, Takashi Hashimoto, Tobias I. Baskin

    PLANT AND CELL PHYSIOLOGY   53 ( 4 ) 699 - 708  2012年04月  [査読有り]  [招待有り]

     概要を見る

    Organelle motility, essential for cellular function, is driven by the cytoskeleton. In plants, actin filaments sustain the long-distance transport of many types of organelles, and microtubules typically fine-tune the motile behavior. In shoot epidermal cells of Arabidopsis thaliana seedlings, we show here that a type of RNA granule, the RNA processing body (P-body), is transported by actin filaments and pauses at cortical microtubules. Interestingly, removal of microtubules does not change the frequency of P-body pausing. Similarly, we show that Golgi bodies, peroxisomes, and mitochondria all pause at microtubules, and again the frequency of pauses is not appreciably changed after microtubules are depolymerized. To understand the basis for pausing, we examined the endoplasmic reticulum (ER), whose overall architecture depends on actin filaments. By the dual observation of ER and microtubules, we find that stable junctions of tubular ER occur mainly at microtubules. Removal of microtubules reduces the number of stable ER tubule junctions, but those remaining are maintained without microtubules. The results indicate that pausing on microtubules is a common attribute of motile organelles but that microtubules are not required for pausing. We suggest that pausing on microtubules facilitates interactions between the ER and otherwise translocating organelles in the cell cortex.

    DOI PubMed

  • The occurrence of ‘bulbs’, a complex configuration of the vacuolar membrane,is affected by mutations of vacuolar SNARE and phospholipase in Arabidopsis.

    Chieko Saito, Tomohiro Uemura, Chie Awai, Motoki Tominaga, Kazuo Ebine, Jun Ito, Takashi Ueda, Hiroshi Abe, Miyo Terao Morita, Masao Tasaka, Akihiko Nakano

    Plant J.   68 ( 1 ) 64 - 73  2011年10月  [査読有り]  [招待有り]

    DOI PubMed

  • Application of Lifeact Reveals F-Actin Dynamics in Arabidopsis thaliana and the Liverwort, Marchantia polymorpha

    Atsuko Era, Motoki Tominaga, Kazuo Ebine, Chie Awai, Chieko Saito, Kimitsune Ishizaki, Katsuyuki T. Yamato, Takayuki Kohchi, Akihiko Nakano, Takashi Ueda

    PLANT AND CELL PHYSIOLOGY   50 ( 6 ) 1041 - 1048  2009年06月  [査読有り]  [招待有り]

     概要を見る

    Actin plays fundamental roles in a wide array of plant functions, including cell division, cytoplasmic streaming, cell morphogenesis and organelle motility. Imaging the actin cytoskeleton in living cells is a powerful methodology for studying these important phenomena. Several useful probes for live imaging of filamentous actin (F-actin) have been developed, but new versatile probes are still needed. Here, we report the application of a new probe called Lifeact for visualizing F-actin in plant cells. Lifeact is a short peptide comprising 17 amino acids that was derived from yeast Abp140p. We used a LifeactVenus fusion protein for staining F-actin in Arabidopsis thaliana and were able to observe dynamic rearrangements of the actin meshwork in root hair cells. We also used LifeactVenus to visualize the actin cytoskeleton in the liverwort Marchantia polymorpha; this revealed unique and dynamic F-actin motility in liverwort cells. Our results suggest that Lifeact could be a useful tool for studying the actin cytoskeleton in a wide range of plant lineages.

    DOI PubMed

  • Auxin transport inhibitors impair vesicle motility and actin cytoskeleton dynamics in diverse eukaryotes

    Pankaj Dhonukshe, Ilya Grigoriev, Rainer Fischer, Motoki Tominaga, David G. Robinson, Jiri Hasek, Tomasz Paciorek, Jan Petrasek, Daniela Seifertova, Ricardo Tejos, Lee A. Meisel, Eva Zazimalova, Theodorus W. J. Gadella, York-Dieter Stierhof, Takashi Ueda, Kazuhiro Oiwa, Anna Akhmanova, Roland Brock, Anne Spang, Jiri Friml

    PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA   105 ( 11 ) 4489 - 4494  2008年03月  [査読有り]  [招待有り]

     概要を見る

    Many aspects of plant development, including patterning and tropisms, are largely dependent on the asymmetric distribution of the plant signaling molecule auxin. Auxin transport inhibitors (ATIs), which interfere with directional auxin transport, have been essential tools in formulating this concept. However, despite the use of ATIs in plant research for many decades, the mechanism of ATI action has remained largely elusive. Using real-time live-cell microscopy, we show here that prominent ATIs such as 2,3,5-triiodobenzoic acid (TIBA) and 2-(1-pyrenoyl) benzoic acid (PBA) inhibit vesicle trafficking in plant, yeast, and mammalian cells. Effects on micropinocytosis, rab5-labeled endosomal motility at the periphery of HeLa cells and on fibroblast mobility indicate that ATIs influence actin cytoskeleton. Visualization of actin cytoskeleton dynamics in plants, yeast, and mammalian cells show that ATIs stabilize actin. Conversely, stabilizing actin by chemical or genetic means interferes with endocytosis, vesicle motility, auxin transport, and plant development, including auxin transport-dependent processes. Our results show that a class of ATIs act as actin stabilizers and advocate that actin-dependent trafficking of auxin transport components participates in the mechanism of auxin transport. These studies also provide an example of how the common eukaryotic process of actin-based vesicle motility can fulfill a plant-specific physiological role.

    DOI PubMed

  • Plant 115-kDa actin-filament bundling protein, P-115-ABP, is a homologue of plant villin and is widely distributed in cells

    E Yokota, L Vidali, M Tominaga, H Tahara, H Orii, Y Morizane, PK Hepler, T Shimmen

    PLANT AND CELL PHYSIOLOGY   44 ( 10 ) 1088 - 1099  2003年10月  [査読有り]  [招待有り]

     概要を見る

    In many cases, actin filaments are arranged into bundles and serve as tracks for cytoplasmic streaming in plant cells. We have isolated an actin-filament bundling protein, which is composed of 115-kDa polypeptide (P-115-ABP), from the germinating pollen of lily, Lilium longiflorum [Nakayasu et al. (1998) Biochem. Biophys. Res. Commun. 249: 61]. P-115-ABP shared similar antigenicity with a plant 135-kDa actin-filament bundling protein (P-135-ABP), a plant homologue of villin. A full-length cDNA clone (ABP115; accession no. AB097407) was isolated from an expression cDNA library of lily pollen by immuno-screening using antisera against P-115-ABP and P-135-ABP. The amino acid sequence of P-115-ABP deduced from this clone showed high homology with those of P-135-ABP and four villin isoforms of Arabidopsis thaliana (AtVLN1, AtVLN2, AtVLN3 and AtVLN4), especially AtVLN4, indicating that P-115-ABP can also be classified as a plant villin. The P-115-ABP isolated biochemically from the germinating lily pollen was able to arrange F-actin filaments with uniform polarity into bundles and this bundling activity was suppressed by Ca2+-calmodulin (CaM), similar to the actin-filament bundling properties of P-135-ABP. The P-115-ABP type of plant villin was widely distributed in plant cells, from algae to land plants. In root hair cells of Hydrocharis dubia, this type of plant villin was co-localized with actin-filament bundles in the transvacuolar strands and the subcortical regions. Microinjection of the antiserum against P-115-ABP into living root hair cells caused the disappearance of transvaculor strands and alteration of the route of cytoplasmic streaming. In internodal cells of Chara corallina in which the P-135-ABP type of plant villin is lacking, the P-115-ABP type showed co-localization with actin-filament cables anchored on the intracellular surface of chloroplasts. These results indicated that plant villins are widely distributed and involved in the organization of actin filaments into bundles throughout the plant kingdom.

    DOI PubMed

  • Higher plant myosin XI moves processively on actin with 35 nm steps at high velocity

    M Tominaga, H Kojima, E Yokota, H Orii, R Nakamori, E Katayama, M Anson, T Shimmen, K Oiwa

    EMBO JOURNAL   22 ( 6 ) 1263 - 1272  2003年03月  [査読有り]  [招待有り]

     概要を見る

    High velocity cytoplasmic streaming is found in various plant cells from algae to angiosperms. We characterized mechanical and enzymatic properties of a higher plant myosin purified from tobacco bright yellow-2 cells, responsible for cytoplasmic streaming, having a 175 kDa heavy chain and calmodulin light chains. Sequence analysis shows it to be a class XI myosin and a dimer with six IQ motifs in the light chain-binding domains of each heavy chain. Electron microscopy confirmed these predictions. We measured its ATPase characteristics, in vitro motility and, using optical trap nanometry, forces and movement developed by individual myosin XI molecules. Single myosin XI molecules move processively along actin with 35 nm steps at 7 mum/s, the fastest known processive motion. Processivity was confirmed by actin landing rate assays. Mean maximal force was similar to0.5 pN, smaller than for myosin IIs. Dwell time analysis of beads carrying single myosin XI molecules fitted the ATPase kinetics, with ADP release being rate limiting. These results indicate that myosin XI is highly specialized for generation of fast processive movement with concomitantly low forces.

    DOI

  • Regulation of root growth by gibberellin in Lemna minor

    S Inada, M Tominaga, T Shimmen

    PLANT AND CELL PHYSIOLOGY   41 ( 6 ) 657 - 665  2000年06月  [査読有り]  [招待有り]

     概要を見る

    Hormonal control of root growth was studied in Lemna minor. Although addition of gibberellic acid (GA(3)) to the culture medium did not promote the root growth, a gibberellin biosynthesis inhibitor, uniconazole P (Un-P), significantly inhibited root growth. Both length and diameter of roots in Un-P-treated plants were significantly smaller than those in control plants, mainly caused by inhibition of cell division. In epidermal cells, the length was slightly decreased and the width increased by Un-P treatment, indicating inhibition of elongation growth. GA(3) completely nullified the inhibition caused by Un-P. Transverse cortical microtubules (CMTs) of epidermal cells in the elongation zone were significantly fragmented by treatment with Un-P, but not by that in the presence of GA(3). The cellulose microfibril array in the Un-P-treated cells was more random and more oblique than that in the control cells. These results suggested that root growth in L. minor is regulated by endogenous gibberellin.

  • The role of plant villin in the organization of the actin cytoskeleton, cytoplasmic streaming and the architecture of the transvacuolar strand in root hair cells of Hydrocharis

    M Tominaga, E Yokota, L Vidali, S Sonobe, PK Hepler, T Shimmen

    PLANTA   210 ( 5 ) 836 - 843  2000年04月  [査読有り]  [招待有り]

     概要を見る

    In many types of plant cell, bundles of actin filaments (AFs) are generally involved in cytoplasmic streaming and the organization of transvacuolar strands. Actin cross-linking proteins are believed to arrange AFs into the bundles. In root hair cells of Hydrocharis dubia (Blume) Baker, a 135-kDa polypeptide cross-reacted with an antiserum against a 135-kDa actin-bundling protein (135-ABP), a villin homologue, isolated from lily pollen tubes. Immunofluorescence microscopy revealed that the 135-kDa polypeptide co-localized with AF bundles in the transvacuolar strand and in the subcortical region of the cells. Microinjection of antiserum against 135-ABP into living root hair cells induced the disappearance of the transvacuolar strand. Concomitantly, thick AF bundles in the transvacuolar strand dispersed into thin bundles. In the root hair cells, AFs showed uniform polarity in the bundles, which is consistent with the in-vitro activity of 135-ABP. These results suggest that villin is a factor responsible for bundling AFs in root hair cells as well as in pollen tubes, and that it plays a key role in determining the direction of cytoplasmic streaming in these cells.

  • Mechanism of inhibition of cytoplasmic streaming by a myosin inhibitor, 2,3-butanedione monoxime

    M Tominaga, E Yokota, S Sonobe, T Shimmen

    PROTOPLASMA   213 ( 1-2 ) 46 - 54  2000年  [査読有り]  [招待有り]

     概要を見る

    On the basis of the inhibition of myosin by 2,3-butanedione monoxime (BDM), the protein's involvement in various cell activities is discussed. However, it has not been established whether BDM inhibits plant myosin. In the present study, the effect of BDM on isolated plant myosin was analyzed in vitro. The sliding between myosin from lily (Lilium longiflorum) pollen tubes and actin filaments from skeletal muscle was inhibited to 25% at a concentration of 60 mM, indicating that BDM can be used as a myosin inhibitor for plant materials. Cytoplasmic streaming was completely inhibited by BDM at 30 mM in lily pollen tubes and at 70 mM in short root hair cells, and at 100 mM in long root hair cells of Hydrocharis dubia. However. BDM at high concentrations induced the disorganization of actin filament bundles in lily pollen tubes and short root hair cells. In addition, cortical microtubules were also fragmented in short root hair cells treated with BDM, suggesting a possible side effect of BDM.

  • Actin cytoskeleton is responsible for the change of cytoplasmic organization in root hair cells induced by a protein phosphatase inhibitor, calyculin A

    E Yokota, N Imamichi, M Tominaga, T Shimmen

    PROTOPLASMA   213 ( 3-4 ) 184 - 193  2000年  [査読有り]  [招待有り]

     概要を見る

    In root hair cells of Limnobium stoloniferum, a protein phospha;ase inhibitor, calyculin A (CA), at concentrations higher than 50 nM inhibits cytoplasmic streaming and induces remarkable morphological changes in the cytoplasm: the transvacuolar strands disperse and spherical cytoplasmic bodies emerge. The mechanism of the morphological changes of the cytoplasm induced by CA was studied by pharmacological analyses. The formation of spherical bodies in cells treated with CA was suppressed by the actin-depolymerizing and -fragmenting drugs latrunculin B and cytochalasin D at concentrations higher than 100 nM and 5 mu M, respectively. In contrast, 100 mu M propyzamide, a microtubule-depolymerizing drug, did not affect the formation of spherical bodies by CA. Interestingly, 60 mM 2,3-butanedione monoxime, an inhibitor of myosin, also suppressed the CA-induced formation of cytoplasmic spherical bodies. These results indicate that the actin cytoskeleton is intimately involved in the morphological changes of the cytoplasm induced by CA.

  • Mechanism of inhibition of cytoplasmic streaming by auxin in root hair cells of Hydrocharis

    M Tominaga, S Sonobe, T Shimmen

    PLANT AND CELL PHYSIOLOGY   39 ( 12 ) 1342 - 1349  1998年12月  [査読有り]  [招待有り]

     概要を見る

    It has been reported that auxin accelerates cytoplasmic streaming at low concentrations and inhibits it at high concentrations in several plant cells. In the present study, the mechanism of inhibition of cytoplasmic streaming by naphthalene acetic acid (NAA) at high concentrations was analyzed in root hair cells of Hydrocharis. Because the effective concentration of NAA inhibiting cytoplasmic streaming decreased when the extracellular pH (pHo) was lowered, it was hypothesized that cytoplasmic streaming is inhibited by NAA via acidification of the cytoplasm, This possibility was supported by the fact that acetic acid, propionic acid and decanoic acid also inhibited cytoplasmic streaming at low pHo. Acidification of the cytoplasm disturbed the orientation of actin filaments (AFs) and disrupted cortical microtubules (MTs). The effects of NAA were reversible; both cytoplasmic streaming and organization of the cytoskeleton were recovered upon removal of NAA. During the recovery, tracks of cytoplasmic streaming in the subcortical region temporarily showed a helical pattern along the longitudinal direction of the cell. Fluorescence staining of cytoskeletons revealed that both AFs and MTs aligned obliquely to the longitudinal axis of the cell. The helical streaming returned to the original reverse fountain streaming after several hours. The simultaneous changes in the organization of both cytoskeletons supported our previous report that the organization of AFs is regulated by MTs.

    DOI

  • Microtubules regulate the organization of actin filaments at the cortical region in root hair cells of Hydrocharis

    M Tominaga, K Morita, S Sonobe, E Yokota, T Shimmen

    PROTOPLASMA   199 ( 1-2 ) 83 - 92  1997年  [査読有り]  [招待有り]

     概要を見る

    We studied the mechanism controlling the organization of actin filaments (AFs) in Hydrocharis root hair cells, in which reverse fountain streaming occurs. The distribution of AFs and microtubules (MTs) in root hair cells were analyzed by fluorescence microscopy and electron microscopy. AFs and MTs were found running in the longitudinal direction of the cell at the cortical region. AFs were observed in the transvacuolar strand, but not MTs. Ultrastructural studies revealed that AFs and MTs were colocalized and that MTs were closer to the plasma membrane than AFs. To examine if MTs regulate the organization of AFs, we carried out a double inhibitor experiment using cytochalasin B (CB) and propyzamide, which are inhibitors of AFs and MTs, respectively. CB reversibly inhibited cytoplasmic streaming while propyzamide alone had no effect on it. However, after treatment with both CB and propyzamide, removal of CB alone did not lead to recovery of cytoplasmic streaming. In these cells, AFs showed a meshwork structure. When propyzamide was also removed, cytoplasmic streaming and the original organization of AFs were recovered. These results strongly suggest that MTs are responsible for the organization of AFs in Hydrocharis root hair cells.

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書籍等出版物

Misc

  • Plant-specific myosin XI, a molecular perspective

    Motoki Tominaga, Akihiko Nakano

    FRONTIERS IN PLANT SCIENCE   3  2012年

    書評論文,書評,文献紹介等  

     概要を見る

    In eukaryotic cells, organelle movement, positioning, and communications are critical for maintaining cellular functions and are highly regulated by intracellular trafficking. Directional movement of motor proteins along the cytoskeleton is one of the key regulators of such trafficking. Most plants have developed a unique actin myosin system for intracellular trafficking. Although the composition of myosin motors in angiosperms is limited to plant-specific myosin classes VIII and XI, there are large families of myosins, especially in class XI, suggesting functional diversification among class XI members. However, the molecular properties and regulation of each myosin XI member remains unclear. To achieve a better understanding of the plant-specific actin myosin system, the characterization of myosin XI members at the molecular level is essential. In the first half of this review, we summarize the molecular properties of tobacco 175-kDa myosin XI, and in the later half, we focus on myosin XI members in Arabidopsis thaliana. Through detailed comparison of the functional domains of these myosins with the functional domain of myosin V, we look for possible diversification in enzymatic and mechanical properties among myosin XI members concomitant with their regulation.

    DOI

  • III 単一分子観察・測定技術によるATPase機構の解析(生体高分子超精密計測学)

    大岩 和弘, 小嶋 寛明, 富永 基樹, 志鷹 裕司, 鳥羽 栞

    兵庫県立大学大学院物質理学研究科・生命理学研究科研究一覧   17  2006年10月

    CiNii

産業財産権

  • 成長が増強された形質転換植物及びその製造方法

    富永 基樹

    特許権

共同研究・競争的資金等の研究課題

  • 可視化による膜交通の分子機構の解明と植物高次システムへの展開

    研究期間:

    2013年05月
    -
    2018年03月
     

     概要を見る

    酵母と植物を材料に用い,高性能化した超解像共焦点ライブイメージング顕微鏡(SCLIM)を駆使して,膜交通を可視化し,小胞体―ゴルジ体間,ゴルジ体内,ゴルジ体以降,およびエンドサイトーシスのさまざまな過程における選別輸送の分子機構を詳細に解析した。積荷の受け渡しを直接可視化することに成功し,従来信じられていたモデルを大きく覆す結果を得た。SCLIMについては,さらに劇的な性能向上に成功し,個々の小胞の空間ダイナミクスをリアルタイムに解析するスペックを達成した。膜交通が植物の高次機能に果たす役割についてもさまざまな解析を行い,トランスゴルジ網が病原菌応答に重要な役割を担っていることを明らかにした

  • ミオシン速度改変による植物特異的細胞内交通機構と高次機能の解析

    研究期間:

    2011年04月
    -
    2014年03月
     

     概要を見る

    原形質流動の主な駆動力として知られるシロイヌナズナミオシンXIに,速度の異なる他種ミオシンのモータードメインを融合することで,速度改変型キメラミオシンXIを開発した。高速・低速型ミオシンXIの発現により原形質流動が高速化・低速化し,植物が大型化・小型化した。植物サイズとミオシン速度のリニアな相関から,原形質流動速度が植物サイズを規定している支配因子の一つであることを世界ではじめて明らかにした

  • 膜交通における選別輸送の分子機構の解明と植物の高次システムへの展開

    研究期間:

    2008年04月
    -
    2014年03月
     

     概要を見る

    細胞内膜交通の問題に生化学、遺伝学と最新のライブイメージング技術を駆使して取り組み、小胞に濃縮した積荷タンパク質を安全かつ確実に受け取る仕組みなど、選別輸送の新たな機構を解明することができた。また酵母から高等植物への展開から、進化の過程で植物が獲得した新たな膜交通機構を明らかにし、従来の動物細胞の研究だけからでは十分に理解できなかったゴルジ体層板形成、ポストゴルジ交通などの複雑な事象を整理する手がかりを得た

  • モータータンパク質の運動特性が細胞内膜輸送に果たす役割

     概要を見る

    本研究では動・植物細胞における膜輸送の駆動力であるミオシンの分子機能を、分子生物学およびライブイメージングの手法を用い解析した。動物において、分子内折りたたみ構造形成能を阻害した変異ミオシンVbをHeLa細胞で発現させることによって、膜交通制御における折りたたみ構造の役割を明らかにした。植物において、全植物ミオシンのクローニングと発現に成功した。ミオシンメンバー間での広範な機能分担が明らかとなり、植物独自のユニークな輸送制御システムを示した

  • 可視化による膜交通の選別分子機構の理解と植物の高次機能への展開

     概要を見る

    次のような研究に着手したが,特別推進研究が採択となったため,年度途中で辞退した。なお本研究計画は特別推進研究の内容に含まれ,引き続き推進していく予定である。1.膜交通の可視化による選別分子機構の解明(1)ゴルジ体槽成熟の分子機構(2)COPII小胞がゴルジ槽を形成する分子機構(3)ポストゴルジネットワーク:エキソサイトーシスとエンドサイトーシスの交差点の理解(4)共焦点レーザー顕微鏡の改良開発(5)FRETイメージングによる活性と分子間相互作用の可視化2.高等植物における膜交通の役割(1)Rab5 GTPaseをツールとした植物エンドサイトーシスの研究(2)植物のポストゴルジ膜交通の解

講演・口頭発表等

  • 動かない植物の原形質流動の謎

    富永基樹  [招待有り]

    大隅基礎科学創成財団,第一回創発セミナー   (東京)  大隅基礎科学創成財団  

    発表年月: 2018年03月

  • 原形質流動の人工的改変による植物のサイズ制御

    富永基樹  [招待有り]

    化学工学会第49回秋季大会   (名古屋)  化学工学会  

    発表年月: 2017年09月

  • 原形質流動速度の人工制御による植物バイオマス増産技術の開発

    富永基樹  [招待有り]

    バイオマスイノベーション研究会   (大阪)  近畿バイオインダストリー振興会議  

    発表年月: 2017年03月

  • 植物制御システムとしての原形質流動

    富永基樹  [招待有り]

    奈良先端大セミナー   (奈良)  奈良先端科学技術大学院大学  

    発表年月: 2016年10月

  • 植物の高次機能を司る原形質流動の分子メカニズム

    富永基樹  [招待有り]

    筑波大学植物分子生学セミナー   (筑波)  筑波大学  

    発表年月: 2016年01月

  • A mystery of busy cytoplasmic streaming in quiet plants

    富永基樹  [招待有り]

    第38回日本分子生物学会,シンポジウム「植物細胞は忙しい:駆け巡るオルガネラの動的制御機構」   (神戸)  日本分子生物学会  

    発表年月: 2015年12月

  • 植物の高次機能を支える原形質流動の分子メカニズム

    富永基樹  [招待有り]

    第1038回東大生物科学セミナー   (東京)  東京大学  

    発表年月: 2015年11月

  • Molecular mechanism and physiological function of cytoplasmic streaming

    富永基樹  [招待有り]

    25th International Conference on Arabidopsis Research (ICAR)   (バンクーバー)  International Conference on Arabidopsis Research  

    発表年月: 2014年08月

  • 動かない植物の細胞内運動の謎

    富永基樹  [招待有り]

    学習院大学生命科学シンポジウム「生命の秘密を解く鍵をもとめて」   (東京)  学習院大学  

    発表年月: 2014年05月

  • 原形質流動による成長制御から考える植物の光戦略

    富永基樹  [招待有り]

    公開シンポジウム「多様な光合成の世界」   (奈良)  光合成学会  

    発表年月: 2014年05月

  • 原形質流動速度の人工的改変による植物のサイズ制御

    富永基樹  [招待有り]

    シンポジウム「細胞を創る操る」   (奈良)  奈良先端科学技術大学院大学  

    発表年月: 2013年11月

  • 植物ミオシン:高次機能を担う分子メカニズム

    富永基樹  [招待有り]

    神谷宣郎先生 生誕百周年記念シンポジウム   (大阪)  大阪大学  

    発表年月: 2013年07月

  • 植物ミオシン ~分子メカニズムから高次機能まで~

    富永基樹  [招待有り]

    大阪大学生物科学セミナー   (大阪)  大阪大学  

    発表年月: 2013年06月

  • Plant size regulation through artificial control of myosin velocity responsible for cytoplasmic streaming.

    Motoki Tominaga  [招待有り]

    Green Biotechnology for Global Sustainability   (大阪)  Osaka University  

    発表年月: 2013年03月

  • Myosin motors and intracellular organelle trafficking.

    Motoki Tominaga  [招待有り]

    Global COE Symposium “Microscopy and Cell Biology”   (兵庫)  Hyogo University  

    発表年月: 2010年03月

  • 植物特異的細胞内交通とミオシンモーター

    富永基樹  [招待有り]

    KARCコロキウム   (神戸)  独立行政法人情報通信研究機構  

    発表年月: 2010年03月

  • 植物細胞内の輸送を担うアクチン-ミオシン駆動系の分子機構

    富永基樹  [招待有り]

    基礎生物学研究所部門公開セミナ―   (愛知)  基礎生物学研究所  

    発表年月: 2009年06月

  • 植物の膜輸送に関与するアクチン-ミオシン駆動系の分子機構

    富永基樹  [招待有り]

    奈良先端大学公開セミナ―   (奈良)  奈良先端科学技術大学院大学  

    発表年月: 2009年

  • 植物細胞におけるアクチン細胞骨格の構築機構とミオシンXIの運動機構

    富永基樹  [招待有り]

    第847回東大生物科学セミナー   (東京)  東京大学  

    発表年月: 2008年

  • 高等植物ミオシンの分子レベルでの運動と制御機構

    富永基樹, 小嶋寛明, 中森鈴奈, 新免輝男, 大岩和弘  [招待有り]

    植物細胞における細胞骨格の機能発現:滑り説から50年   (愛知)  基礎生物学研究所  

    発表年月: 2006年12月

  • Single molecule analysis of higher plant myosin XI responsible for cytoplasmic streaming.

    Motoki Tominaga  [招待有り]

    Gordon Research Conference (Plant and Fungal cytoskeleton)   (ニューハンプシャー)  Gordon Research Conference  

    発表年月: 2004年08月

  • 高等植物ミオシンの分子レベルでの運動と制御機構

    富永基樹, 大岩和弘  [招待有り]

    21世紀COE生命科学若手ワークショップ   (兵庫)  兵庫県立大学  

    発表年月: 2004年01月

  • 植物細胞におけるアクチン細胞骨格の構築機構とミオシンXIの運動機構

    富永基樹, 大岩和弘  [招待有り]

    理研セミナー   (埼玉)  理化学研究所  

    発表年月: 2004年

▼全件表示

特定課題研究

  • 人工レバーアームを備えた高速型ミオシンXIによる植物バイオマス増産システムの開発

    2020年  

     概要を見る

    これまで,植物細胞内の原形質流動を駆動しているモータータンパク質ミオシン XI の高速化により,様々なモデル植物の大型化や種子生産の増加に成功した。今後,本技術を過酷なフィールドで実装するには,ミオシンの恒常的高発現による更なる大型化が必要である。しかしながら,これまで高速型ミオシンで恒常的高発現を行うと,植物に致死的な影響がでた。原因の一つとして,ミオシンの運動に不可欠な軽鎖カルモジュリンの細胞内での枯渇が考えられる。本研究では,“軽鎖”を必要としない“人工レバーアーム”を供えた高速型ミオシンXIを遺伝子工学的に設計し構築を行った。

  • 先祖型ミオシンXI発現による植物細胞内輸送の研究

    2018年  

     概要を見る

     本研究では,植物の進化に伴い多様化したミオシンXIの最も原始的な機能の同定を試みた。そのため,陸上植物進化の基部に位置するゼニゴケのミオシンXIに蛍光タンパク質を融合し,高等植物シロイヌナズナのミオシンXI多重ノックアウト株で発現させた。その結果,ゼニゴケミオシンXIは,シロイヌナズナ細胞内において原形質流動を発生させ,多重ノックアウトによる成長阻害を回復させる事が明らかとなった。すなわち,植物ミオシンXIの分子機能が,原形質流動を発生し成長を制御するため進化的に保存されている事が示唆された。本研究成果は,Plant Biology 2018や日本植物学会第82回大会等で発表した。

  • 先祖型ミオシンXI発現による植物細胞内輸送の研究

    2017年  

     概要を見る

     本研究は,陸上植物の進化に伴い多様化したミオシンXIの最も原始的な機能を同定することを目的とする。そのため,陸上植物進化の基部に位置するゼニゴケのミオシンXIに蛍光タンパク質を融合し,高等植物シロイヌナズナの培養細胞内で発現させ,ライブイメージング解析を行った。その結果,ゼニゴケミオシンXIは,シロイヌナズナ細胞内において小胞体と一部共局在し,活発な運動を行う事が明らかとなった。すなわち,植物ミオシンXIが持つ最も原始的な機能として、オルガネラ輸送を伴った原形質流動の発生にある可能性が示唆された。本研究成果は,第7回分子モーター討論会,日本植物学会第81回大会で発表した。

 

現在担当している科目

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