Search

Your search keyword '"Iwasaki, Hirohide"' showing total 38 results
Start Over Author "Iwasaki, Hirohide"
38 results on '"Iwasaki, Hirohide"'

10. Insight into the function of a unique voltage-sensor protein (TMEM266) and its short form in mouse cerebellum

Author

Kawai, Takafumi, primary, Narita, Hirotaka, additional, Konno, Kohtarou, additional, Akter, Sharmin, additional, Andriani, Rizki Tsari, additional, Iwasaki, Hirohide, additional, Nishikawa, Shoji, additional, Yokoi, Norihiko, additional, Fukata, Yuko, additional, Fukata, Masaki, additional, Wiriyasermkul, Pattama, additional, Kongpracha, Pornparn, additional, Nagamori, Shushi, additional, Takao, Keizo, additional, Miyakawa, Tsuyoshi, additional, Abe, Manabu, additional, Sakimura, Kenji, additional, Watanabe, Masahiko, additional, Nakagawa, Atsushi, additional, and Okamura, Yasushi, additional

Published
2022
Full Text
View/download PDF

21. Voltage-sensing phosphatase: actions and potentials

Author

Okamura, Yasushi, Murata, Yoshimichi, and Iwasaki, Hirohide

Subjects
Neurons, PTEN Phosphohydrolase, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Ion Channels, Phosphoric Monoester Hydrolases, Membrane Potentials, Protein Structure, Tertiary, Enzyme Activation, Phosphotransferases (Alcohol Group Acceptor), Phosphatidylinositol Phosphates, Animals, Humans, Topical Review, Ion Channel Gating
Abstract

Voltage sensors have been well studied in voltage-gated ion channels for neuronal excitation and muscle contraction. The recent discovery of a voltage-sensing phosphatase, VSP, has changed the idea that voltage sensors are unique to ion flux through membranes. Recent findings on mechanisms and potential applications of VSP are reviewed.

Published
2008

29. Comprehensive analysis of the ascidian genome reveals novel insights into the molecular evolution of ion channel genes

Author

Okamura, Yasushi, primary, Nishino, Atsuo, additional, Murata, Yoshimichi, additional, Nakajo, Koichi, additional, Iwasaki, Hirohide, additional, Ohtsuka, Yukio, additional, Tanaka-Kunishima, Motoko, additional, Takahashi, Nobuyuki, additional, Hara, Yuji, additional, Yoshida, Takashi, additional, Nishida, Motohiro, additional, Okado, Haruo, additional, Watari, Hirofumi, additional, Meinertzhagen, Ian A., additional, Satoh, Nori, additional, Takahashi, Kunitaro, additional, Satou, Yutaka, additional, Okada, Yasunobu, additional, and Mori, Yasuo, additional

Published
2005
Full Text
View/download PDF

34. 2-Aminoethyl diphenylborinate analogues: Selective inhibition for store-operated Ca2+ entry

Author

Zhou, Hong, Iwasaki, Hirohide, Nakamura, Takeshi, Nakamura, Kyoko, Maruyama, Takayuki, Hamano, Shin-ichi, Ozaki, Shoichiro, Mizutani, Akihiro, and Mikoshiba, Katsuhiko

Subjects
*VITAMIN B complex, *ADENOSINE triphosphatase, *CELL membranes, *SUGARS
Abstract

Abstract: Capacitative calcium entry (CCE), the mechanism that replenishes the internal Ca2+ stores with Ca2+ from the extracellular milieu in response to depletion of the store, is mediated by Ca2+ channels in the plasma membrane generally referred to as store-operated channels (SOCs). However, the roles of SOCs in the more physiological context have been fully elucidated. 2-Aminoethyl diphenylborinate (2-APB) strongly inhibits SOCs, as well as inositol-1,4,5 trisphosphate (IP3) receptors. In the present study, we screened a library of 166 2-APB analogues for effects on CCE and IP3-induced Ca2+ release in order to discover specific SOC inhibitors, and found that some blocked both store-operated and receptor-operated Ca2+ influx more strongly and selectively than 2-APB. Indeed, these new compounds ceased the prolonged intracellular Ca2+ oscillations induced by a low concentration of ATP in CHO-K1 cells. These novel SOC inhibitors will be valuable pharmacological and biochemical tools for elucidating the physiological roles. [Copyright &y& Elsevier]

Published
2007
Full Text
View/download PDF

35. Ca2+ induces macropinocytosis via F-actin depolymerization during growth cone collapse

Author

Kabayama, Hiroyuki, Nakamura, Takeshi, Takeuchi, Makoto, Iwasaki, Hirohide, Taniguchi, Masahiko, Tokushige, Naoko, and Mikoshiba, Katsuhiko

Subjects
*CALCIUM channels, *PINOCYTOSIS, *RYANODINE, *CELL membranes, *ACTIN, *SEMAPHORINS, *BIOLOGICAL transport, *ENDOCYTOSIS
Abstract

Abstract: Growth cone collapse occurs in repulsive axon guidance and is accompanied by a reduction in the surface area of the plasma membrane of growth cones. However, the mechanism of this reduction is unclear. Here, we show that during growth cone collapse, caffeine-induced Ca2+ release from ryanodine-sensitive Ca2+ stores triggers the formation of large vacuoles in growth cones by macropinocytosis, a clathrin-independent endocytosis for the massive retrieval of the cellular plasma membrane, and subsequent retrograde membrane transport. We observed a significant correlation of the area of caffeine-induced macropinosomes with growth cone collapse. We also detected macropinocytosis induced by semaphorin 3A, a typical repulsive cue, and correlation between the area of semaphorin 3A-induced macropinocytic vacuoles and growth cone collapse. Moreover, jasplakinolide, an inhibitor of F-actin depolymerization, blocked caffeine-induced macropinocytosis. We propose that the coordinated regulation of actin cytoskeletal reorganization and macropinocytosis-mediated retrograde membrane trafficking may contribute to Ca2+-induced axon growth inhibition. [Copyright &y& Elsevier]

Published
2009
Full Text
View/download PDF

36. Ultrastructural Observation of Glutamatergic Synapses by Focused Ion Beam Scanning Electron Microscopy (FIB/SEM).

Author

Takahashi-Nakazato A, Parajuli LK, Iwasaki H, Tanaka S, and Okabe S

Subjects
Animals, Dendritic Spines metabolism, Synapses metabolism, Tissue Fixation methods, Dendritic Spines ultrastructure, Glutamic Acid metabolism, Microscopy, Electron, Scanning methods, Receptors, Glutamate metabolism, Synapses ultrastructure
Abstract

A thorough understanding of the synaptic ultrastructure is necessary to bridge our current knowledge gap about the relationship between neuronal structure and function. Recent development of focused ion beam scanning electron microscopy (FIB/SEM) has made it possible to image neuronal structures with high speed and efficiency. Here, we present our routine protocol for correlative two-photon microscopy and FIB/SEM imaging of glutamatergic synapses. Femtosecond-pulsed near-infrared laser was used to create fiducial marks around the dendrite of interest in aldehyde-fixed tissues. Thereafter, samples were subjected to en bloc staining with rOTO (reduced osmium tetroxide-thiocarbohydrazide-osmium tetroxide), followed by lead aspartate and uranyl acetate to enhance tissue contrast. Reliable detection of postsynaptic density (PSD) and plasma membrane contours by the sample preparation protocol optimized for FIB/SEM allows us to precisely evaluate morphological features that shape glutamatergic synaptic transmission.

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results