Biophysics and Physicobiology Editors' Choice Award

Biophysics and Physicobiology Editors' Choice Award

日本生物物理学会では、前年にBiophysics and Physicobiology誌に掲載された論文(依頼論文は原則対象外)の中から、編集委員会による選考を経て、生物物理学に寄与するユニークな論文に対して、「Biophysics and Physicobiology Editors' Choice Award」を授与します。


第5回Biophysics and Physicobiology Editors' Choice Award受賞論文(2018)

“Mechanical properties of spindle poles are symmetrically balanced”
 Kazuya Suzuki, Takeshi Itabashi, Shin’ichi Ishiwata
 Biophysics and Physicobiology, Vol.14, pp. 1-11 (2017)

 The paper by K. Suzuki, T. Itabashi and S. Ishiwata reported intriguing experimental results on the pole mechanics in the self-assembled spindle in Xenopus egg extracts. They demonstrated that the spindle possessed a mechanism to dynamically maintain its symmetry in the mechanical properties. The symmetry of the mechanical (elastic) properties of the pole region was maintained even after the mechanical perturbation introduced by a pair of glass microneedles. When one pole structure was widened, the opposite pole structure spontaneously widened, resulting in the formation of the spindle with barrel-like shape. Conversely, when one end region of the barrel-like structure was compressed, the other region was also narrowed, resulting in the reformation of spindle structure. The results clearly displayed the robustness in the maintenance of the symmetrical structure of spindle. This unique experimental method and the surprising results should deserve the Editors’ Choice Award of Biophysics and Physicobiology.

“Kinetic characteristics of chimeric channelrhodopsins implicate the molecular identity involved in desensitization”
Alemeh Zamani, Shigeo Sakuragi, Toru Ishizuka, Hiromu Yawo
Biophysics and Physicobiology, Vol. 14, pp. 13-22 (2017)

 Channelrhodopsin is a light-gated ion channel attached with a retinal as a light-absorbing chromophore. It has been a critical tool for Optogenetics which has recently attracted much attention. In this study, the molecular mechanism of channel activity in channelrhodopsin was analyzed by electrophysiology, using chimeric proteins made from two channelrhodopsins with different characteristics. When channelrhodopsin absorbs light, it generates a transient photocurrent which slightly attenuates before reaching a steady-state during prolonged irradiation. The authors showed that transmembrane helices 1 and 2 (TM1 and TM2) were both involved in the generation and dissipation of channel conductance. Additionally, their results suggest that TM4 is involved in the generation, whereas TM5 is involved in the dissipation of channel conductance. This research stands out for its use of electrophysiology to analyze the molecular mechanism. By combing this approach, which can directly measure channel activity, with structural and spectroscopic approaches, authors are able to provide deep insight into the mechanism of channel activity. The achievements are worth awarding the Editors' Choice Award of Biophysics and Physicobiology.

 “Molecular properties of a DTD channelrhodopsin from Guillardia theta”
 Yumeka Yamauchi, Masae Konno, Shota Ito, Satoshi Tsunoda, Keiichi Inoue, Hideki Kandori
Biophysics and Physicobiology, Vol. 14, pp. 57-66 (2017)

 Microbial rhodopsins are membrane proteins containing a retinal as a light absorbing chromophore. They are widely found in archaea, eubacteria and eukaryotes (fungal and algal species), and exhibit a wide range of functions, such as light-driven ion pumps, light-gated ion channels, light sensors and light-activated enzymes. Using electrophysiological and spectroscopic techniques, the authors investigated molecular properties of Guillardia theta channelrhodopsin (DTD ChRs). This channelrhodopsin is characterized by a DTD motif, which is usually conserved among pump rhodopsins. Their results showed that in addition functioning as a light-gated cation channel, DTD ChRs also functioned as an outward proton pump. Furthermore, they showed that unlike ordinary channelrhodopsins, its channel closing state was directly coupled to the re-protonation of the retinal chromophore, and that the accompanying protein conformational changes were much smaller. These results indicate the presence of new mechanism of channel formation in microbial rhodopsins and will deepen our understanding of the molecular basis of the functional diversity in microbial rhodopsins. These results deserve the Editors' Choice Award of Biophysics and Physicobiology.

 “Demonstration of Correlative Atomic Force and Transmission Electron Microscopy Using Actin Cytoskeleton”
 Katsuya Shimabukuro, Hiroki Konno, Yutaro Yamada 
Biophysics and Physicobiology, Vol. 14, pp. 111-117 (2017)

 The authors proposed the novel technique to observe fine structures with correlative atomic force microscopy (AFM) and transmission electron microscopy (TEM), and demonstrated images of cytoskeletal protein, actin, as a test. Their trial, an integration of immuno-TEM and AFM provided us with a new possibility of identifying individual molecules. The current usages are still limited, but the bright future of correlative microscopic techniques involving some light microscopy can be seen in the paper. High expectation in the next substantial and technical improvement, that is the visualization of complex biological systems by connecting live imaging and atomic structure, permeates in this paper.

“The change of picrotoxin-induced epileptiform discharges to the beta oscillation by carbachol in rat hippocampal slices”
 Ayumi Hashimoto, Toyohiro Sawada,Kiyohisa Natsume
 Biophysics and Physicobiology, Vol. 14, pp. 137-146 (2017)

 The authors studied the effects of acetylcholine receptors on epileptiform discharges in the CA3 region in the hippocampus using pharmacological and electrophysiological techniques. They found that the dose-dependent alternation of the activation of acetylcholine receptors provide three different stages, i.e. the epileptiform discharges, the bursts of theta oscillation, and the bursts of the beta oscillation. This result will have a great impact on the future studies of hippocampus and acetylcholine receptors.

Biophysics and Physicobiology編集委員会