A5058058056- Cellular Mechanics and Interactions
- Advanced Electron Microscopy Techniques and Applications
- Force Microscopy Techniques and Applications
- Microtubule and mitosis dynamics
- Cardiomyopathy and Myosin Studies
- Bacteriophages and microbial interactions
- Advanced Fluorescence Microscopy Techniques
- Photosynthetic Processes and Mechanisms
- Bacterial Genetics and Biotechnology
- Biotin and Related Studies
- Electron and X-Ray Spectroscopy Techniques
- Cellular transport and secretion
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Botulinum Toxin and Related Neurological Disorders
- Protist diversity and phylogeny
- Protein Structure and Dynamics
- Enzyme Structure and Function
- Cell Image Analysis Techniques
- Alzheimer's disease research and treatments
- RNA and protein synthesis mechanisms
- bioluminescence and chemiluminescence research
- Hemoglobin structure and function
- Neurological disorders and treatments
- Polymer Surface Interaction Studies
Nagoya University
2016-2025
Academia Sinica
2023
Kyoto University
2023
Yokogawa Electric (Japan)
2023
University of Bristol
2023
University of Wisconsin–Madison
2023
Nagoya City University Hospital
2023
Japan Science and Technology Agency
2006-2016
SPring-8
2006-2014
Graduate School USA
2011
Actin depolymerizing factor (ADF) and cofilin accelerate actin dynamics by severing disassembling filaments. Here, we present the 3.8 Å resolution cryo-EM structure of cofilactin (cofilin-decorated filament). The subunit (C-form) is distinct from those F-actin (F-form) monomeric (G-form). During transition between these three conformations, inner domain (subdomains 3 4) majority subdomain 1 move as two separate rigid bodies. cofilin-actin interface consists parts. Based on body movements...
Using correlated live-cell imaging and electron tomography we found that actin branch junctions in protruding treadmilling lamellipodia are not concentrated at the front as previously supposed, but link filament subsets which there is a continuum of distances from junction to plus ends, for up least 1 μm. When sites were observed closely spaced on same their separation was commonly multiple helical repeat 36 nm. Image averaging tomograms yielded model vivo 2.9 nm resolution, comparable with...
Abstract In vivo cell division protein FtsZ from E. coli forms rings and spirals which have only been observed by low resolution light microscopy. We show that these suprastructures are likely formed molecular crowding is a predominant factor in prokaryotic cells enhances the weak lateral bonds between proto‐filaments. Although assembles into single proto‐filaments dilute aqueous buffer, with agents above critical concentration, it polymorphic supramolecular structures including toroids...
The major cytoskeleton protein actin undergoes cyclic transitions between the monomeric G-form and filamentous F-form, which drive organelle transport cell motility. This mechanical work is driven by ATPase activity at catalytic site in F-form. For deeper understanding of cellular functions, reaction mechanism must be elucidated. Here, we show that a single molecule trapped F-form fragmin domain-1 binding present their crystal structures ATP analog-, ADP-Pi-, ADP-bound forms, 1.15-Å...
The actin capping protein (CP) tightly binds to the barbed end of filaments, thus playing a key role in actin-based lamellipodial dynamics. V-1 and CARMIL proteins directly bind CP inhibit filament activity CP. completely inhibits from interacting with end, whereas act on end-bound facilitate its dissociation (called uncapping activity). Previous studies have revealed striking functional differences between two regulators. However, molecular mechanisms describing how these remains poorly...
Significance It remains obscure how actin polymerizing and depolymerizing activities cooperate to control diverse dynamics. Formins rotate along the long-pitch helix of F-actin during processive elongation (helical rotation), which may twist in opposite direction cofilin-induced twisting. In this study, we show that a mammalian formin mDia1 generates resistant cofilin. Tethered elongating from immobilized contained less twisted portion EM analysis exhibited resistance severing activity...
Several pathogens induce propulsive actin comet tails in cells they invade to disseminate their infection. They achieve this by recruiting factors for nucleation, the Arp2/3 complex, and polymerization regulators from host cytoplasm. Owing limited information on structural organization of comets particular spatial arrangement filaments engaged propulsion, underlying mechanism pathogen movement is currently speculative controversial. Using electron tomography we have resolved...
Cytoplasmic dynein is a large, microtubule-dependent molecular motor (1.2 MDa). Although the structure of by itself has been characterized, its conformation in complex with microtubules still unknown. Here, we used cryoelectron microscopy (cryo-EM) to visualize interaction between and microtubules. Most molecules nucleotide-free state are bound microtubule defined orientation. A 3D image reconstruction revealed that dynein's head domain, formed ring-like arrangement AAA+ domains, located...
Abstract An improved unroofing method enabled the cantilever of an atomic force microscope (AFM) to reach directly into a cell visualize intracellular cytoskeletal actin filaments, microtubules, clathrin coats and caveolae in phosphate-buffered saline (PBS) at higher resolution than conventional electron microscopy. All filaments clearly exhibited short periodicity approximately 5–6 nm, which was derived from globular actins linked each other form as well long helical periodicity. The...
Bacterial microcompartments are proteinaceous shells that encase specialized metabolic processes in bacteria. Recent advances simplification of these intricate have encouraged bioengineering efforts. Here, we construct minimal derived from the Halothiobacillus neapolitanus α-carboxysome, which term Cso-shell. Using cryogenic electron microscopy, atomic-level structures two shell forms were obtained, reinforcing notions evolutionarily conserved features bacterial microcompartment...
Tubulins are critical for the internal organization of eukaryotic cells, and understanding their emergence is an important question in eukaryogenesis. Asgard archaea closest known prokaryotic relatives to eukaryotes. Here, we elucidated apo nucleotide-bound x-ray structures tubulin from hydrothermal living Odinarchaeota (OdinTubulin). The guanosine 5'-triphosphate (GTP)-bound structure resembles a microtubule protofilament, with GTP bound between subunits, coordinating "+" end subunit...
A variety of biological roles mechanical forces have been proposed in cell biology, such as signaling pathways for survival, development, growth, and differentiation. Mechanical alter the conditions within cells their environment, which strongly influences reorganization actin cytoskeleton. Single-molecule imaging studies filaments led to hypothesis that filament acts a mechanosensor; e.g., increases tension conformation affinity regulatory proteins. However, our understanding molecular...
Abstract Cytochalasin D (CytoD) is widely used to inhibit actin polymerization, but the underlying regulatory mechanism unclear. We addressed this using Total Internal Reflection Fluorescence (TIRF) microscopy. Our time course depolymerization assay of individual filaments showed that CytoD tightly caps barbed end, with an estimated K m value for inhibition 4.1 nM and a duration ∼1 min. Consistently, in polymerization assays, at concentrations near completely suppressed end elongation....
Abstract The spectraplakin family protein GAS2 was originally identified as a growth arrest-specific protein, and recent studies have revealed its involvement in multiple cellular processes. Its dual interaction with actin filaments microtubules highlights essential role cytoskeletal organization, such cell division, apoptosis, possibly tumorigenesis. However, the structural basis of dynamics regulation by remains unclear. In this study, we present cryo-electron microscopy structures type 3...
Type II plasmid partition systems utilize ParM NTPases in coordination with a centromere-binding protein called ParR to mediate accurate DNA segregation, process critical for retention. The Staphylococcus aureus pSK41 is medically important that confers resistance multiple antibiotics, disinfectants, and antiseptics. In the first step of partition, binds its centromere form superhelical complex recruits ParM, which then mediates separation. homologous R1 known actin homologue, suggesting it...
Actin filaments are polar structures that exhibit a fast growing plus end and slow minus end. According to their organization in cells, parallel or antiparallel arrays, they can serve, respectively, protrusions contractions. The determination of actin filament polarity subcellular compartments is therefore required establish local function. Myosin binding has previously been the sole method determination. Here, we report first direct cell without myosin binding. Negatively stained...