A5021368945- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Cardiomyopathy and Myosin Studies
- Plant Reproductive Biology
- Cellular Mechanics and Interactions
- Photosynthetic Processes and Mechanisms
- Microtubule and mitosis dynamics
- Plant Molecular Biology Research
- Crystallography and molecular interactions
- Plant Micronutrient Interactions and Effects
- Plant nutrient uptake and metabolism
- Muscle Physiology and Disorders
- Polysaccharides and Plant Cell Walls
- Studies on Chitinases and Chitosanases
- Plant biochemistry and biosynthesis
- Cellular transport and secretion
- Aquatic Invertebrate Ecology and Behavior
- Nuclear Structure and Function
- Electrospun Nanofibers in Biomedical Applications
- Biocrusts and Microbial Ecology
- Bacteriophages and microbial interactions
- Postharvest Quality and Shelf Life Management
- Lipid metabolism and biosynthesis
- Polymer-Based Agricultural Enhancements
- Silk-based biomaterials and applications
Waseda University
2016-2025
Chiba University
2021
RIKEN Center for Biosystems Dynamics Research
2021
Japan Science and Technology Agency
2012-2015
RIKEN Center for Advanced Photonics
2013-2014
RIKEN Advanced Science Institute
2008-2012
National Institute of Information and Communications Technology
2008-2012
Advanced Science Research Center
2003-2005
NTL Institute for Applied Behavioral Science
2003
Himeji University
1997-2000
Many aspects of plant development, including patterning and tropisms, are largely dependent on the asymmetric distribution signaling molecule auxin. Auxin transport inhibitors (ATIs), which interfere with directional auxin transport, have been essential tools in formulating this concept. However, despite use ATIs research for many decades, mechanism ATI action has remained elusive. Using real-time live-cell microscopy, we show here that prominent such as 2,3,5-triiodobenzoic acid (TIBA)...
Actin plays fundamental roles in a wide array of plant functions, including cell division, cytoplasmic streaming, morphogenesis and organelle motility. Imaging the actin cytoskeleton living cells is powerful methodology for studying these important phenomena. Several useful probes live imaging filamentous (F-actin) have been developed, but new versatile are still needed. Here, we report application probe called Lifeact visualizing F-actin cells. short peptide comprising 17 amino acids that...
Myosins are important motor proteins that associate with the actin cytoskeleton. Structurally, myosins function as heteromeric complexes where smaller light chains, such calmodulin (CaM), bind to isoleucine-glutamine (IQ) domains in neck region facilitate mechano-enzymatic activity. We recently identified Arabidopsis CaM-like (CML) CML13 and CML14 interactors of containing multiple IQ domains, including a myosin VIII. Here, we demonstrate CaM, CML13, all four VIII isoforms. Among CMLs tested...
Organelle motility, essential for cellular function, is driven by the cytoskeleton. In plants, actin filaments sustain long-distance transport of many types organelles, and microtubules typically fine-tune motile behavior. shoot epidermal cells Arabidopsis thaliana seedlings, we show here that a type RNA granule, processing body (P-body), transported pauses at cortical microtubules. Interestingly, removal does not change frequency P-body pausing. Similarly, Golgi bodies, peroxisomes,...
From germinating pollen of lily, two types villins, P-115-ABP and P-135-ABP, have been identified biochemically. Ca(2+)-CaM-dependent actin-filament binding bundling activities demonstrated for both villins previously. Here, we examined the effects lily on polymerization depolymerization actin. P-135-ABP present in a crude protein extract prepared from bound to DNase I affinity column Ca(2+)-dependent manner. Purified reduced lag period that precedes actin filament monomers presence either...
In eukaryotic cells, organelle movement, positioning, and communications are critical for maintaining cellular functions highly regulated by intracellular trafficking. Directional movement of motor proteins along the cytoskeleton is one key regulators such Most plants have developed a unique actin-myosin system Although composition myosin motors in angiosperms limited to plant-specific classes VIII XI, there large families myosins, especially class suggesting functional diversification among...
Land plants possess myosin classes VIII and XI. Although some information is available on the molecular properties of class XI myosins, myosins are not characterized. Here, we report first analysis enzymatic myosin. The motor domain Arabidopsis myosin, ATM1 (ATM1-MD), plus one IQ motif (ATM1-1IQ) were expressed in a baculovirus system ATM1-MD ATM1-1IQ had low actin-activated Mg(2+)-ATPase activity (Vmax = 4 s(-1)), although their affinities for actin high (Kactin μM). actin-sliding...
Cytoplasmic streaming with extremely high velocity (∼70 μm s-1) occurs in cells of the characean algae (Chara). Because cytoplasmic is caused by myosin XI, it has been suggested that a XI 70 s-1, fastest measured so far, exists Chara cells. However, previously cloned corallina (CcXI) was about 20 one-third Recently, genome sequence braunii published, revealing this alga four genes. We these (CbXI-1, 2, 3, and 4) their velocities. While velocities CbXI-3 CbXI-4 motor domains (MDs) were...
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 lily, Lilium longiflorum [Nakayasu et al. (1998) BIOCHEM: Biophys. Res. Commun. 249: 61]. P-115-ABP shared similar antigenicity with a 135-kDa protein (P-135-ABP), homologue villin. A full-length cDNA clone (ABP115; accession no. AB097407)...
Plant myosin XI acts as a motive force for cytoplasmic streaming through interacting with actin filaments within the cell. Arabidopsis thaliana (At) has 13 genes belonging to family. Previous reverse genetic approaches suggest that At XIs are partially redundant, but functionally diverse their specific tasks plant. However, tissue-specific expression and enzymatic properties of have date been poorly understood, primarily because difficulty in cloning expressing large proteins. In this study,...
The plant vacuole fulfills a variety of functions, and is essential for growth development. We previously identified complex mobile structures on the continuous vacuolar membrane, which we refer to as 'bulbs'. To ascertain their biological significance function, searched markers associated with bulbs, mutants that show abnormalities respect bulbs. observed bulb-like after expression non-membranous proteins well functional soluble N-ethylmaleimide-sensitive factor attachment protein receptor...
Hormonal control of root growth was studied in Lemna minor. Although addition gibberellic acid (GA3) to the culture medium did not promote growth, a gibberellin biosynthesis inhibitor, uniconazole P (Un-P), significantly inhibited growth. Both length and diameter roots Un-P-treated plants were smaller than those plants, mainly caused by inhibition cell division. In epidermal cells, slightly decreased width increased Un-P treatment, indicating elongation GA3 completely nullified Un-P....
Arabidopsis possesses 13 genes encoding class-XI myosins. Among these, myosin XI-I is phylogenetically distant. To examine the molecular properties of thaliana (At XI-I), we performed in vitro mechanical and enzymatic analyses using recombinant constructs At XI-I. Unlike other biochemically studied myosins, showed extremely low actin-activated ATPase activity (Vmax = 3.7 Pi s(-1) head(-1)). The actin-sliding velocity was 0.25 µm s(-1), >10 times lower than those ADP dissociation rate from...
The 175-kDa myosin-11 from Nicotiana tabacum (Nt(175kDa)myosin-11) is exceptional in its mechanical activity as it the fastest known processive actin-based motor, moving 10 times faster than structurally related class 5 myosins. Although this ability might be essential for long-range organelle transport within larger plant cells, kinetic features underlying fast movement of Nt(175kDa)myosin-11 still remain unexplored. To address this, we generated a single-headed motor domain construct and...
It has been reported that auxin accelerates cytoplasmic streaming at low concentrations and inhibits it high in several plant cells. In the present study, mechanism of inhibition by naphthalene acetic acid (NAA) was analyzed root hair cells Hydrocharis. Because effective concentration NAA inhibiting decreased when extracellular pH (pHo) lowered, hypothesized is inhibited via acidification cytoplasm. This possibility supported fact acid, pro-pionic decanoic also pHo. Acidification cytoplasm...
There are two classes of myosin, XI and VIII, in higher plants. Myosin moves actin filaments at high speed its enzyme activity is also very high. In contrast, myosin VIII slowly with low activity. Because most these enzymatic motile activities were measured using animal skeletal muscle α-actin, but not plant actin, they would accurately reflect the actual cells. We thus motor domains Arabidopsis isoforms (MYA2, XI-B), one isoform (ATM1), by three (ACT1, ACT2, ACT7). The different from those...