著者

Susumu Yoshizawa Tomonori Azuma Keiichi Kojima Keisuke Inomura Masumi Hasegawa Yosuke Nishimura Masuzu Kikuchi Gabrielle Armin Yuya Tsukamoto Hideaki Miyashita Kentaro Ifuku Takashi Yamano Adrian Marchetti Hideya Fukuzawa Yuki Sudo Ryoma Kamikawa

出版者

Japanese Society of Microbial Ecology / Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant Microbe Interactions / Japanese Society for Extremophiles

雑誌

Microbes and Environments (ISSN:13426311)

巻号頁・発行日

vol.38, no.2, pp.ME23015, 2023 (Released:2023-06-20)

参考文献数

46

被引用文献数

4

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Diatoms are a major phytoplankton group responsible for approximately 20% of carbon fixation on Earth. They perform photosynthesis using light-harvesting chlo­rophylls located in plastids, an organelle obtained through eukaryote-eukaryote endosymbiosis. Microbial rhodopsin, a photoreceptor distinct from chlo­rophyll-based photosystems, was recently identified in some diatoms. However, the physiological function of diatom rhodopsin remains unclear. Heterologous expression techniques were herein used to investigate the protein function and subcellular localization of diatom rhodopsin. We demonstrated that diatom rhodopsin acts as a light-driven proton pump and localizes primarily to the outermost membrane of four membrane-bound complex plastids. Using model simulations, we also examined the effects of pH changes inside the plastid due to rhodopsin-mediated proton transport on photosynthesis. The results obtained suggested the involvement of rhodopsin-mediated local pH changes in a photosynthetic CO2-concentrating mechanism in rhodopsin-possessing diatoms.

著者

Hidetoshi Yoshitani Akihiro Isotani Jae-Kwan Song Shinichi Shirai Hiromi Umeda Jeong Yoon Jang Takeshi Onoue Misako Toki Byung-Joo Sun Dae-Hee Kim Nobuyuki Kagiyama Akihiro Hayashida Jong-Min Song Masataka Eto Yosuke Nishimura Kenji Ando Michiya Hanyu Kiyoshi Yoshida Robert A. Levine Yutaka Otsuji

出版者

The Japanese Circulation Society

雑誌

Circulation Journal (ISSN:13469843)

巻号頁・発行日

pp.CJ-18-0390, (Released:2018-08-22)

参考文献数

24

被引用文献数

3

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Background: Basal interventricular septum (IVS) hypertrophy (BSH) with reduced basal IVS contraction and IVS-aorta angle is frequently associated with aortic stenosis (AS). BSH shape suggests compression by the longitudinally elongated ascending aorta, causing basal IVS thickening and contractile dysfunction, further suggesting the possibility of aortic wall shortening to improve the BSH. Surgical aortic valve replacement (SAVR), as opposed to transcatheter AVR (TAVR), includes aortic wall shortening by incision and stitching on the wall and may potentially improve BSH. We hypothesized that BSH configuration and its contraction improves after SAVR in patients with AS. Methods and Results: In 32 patients with SAVR and 36 with TAVR for AS, regional wall thickness and systolic contraction (longitudinal strain) of 18 left ventricular (LV) segments, and IVS-aorta angle were measured on echocardiography. After SAVR, basal IVS/average LV wall thickness ratio, basal IVS strain, and IVS-aorta angle significantly improved (1.11±0.24 to 1.06±0.17; −6.2±5.7 to −9.1±5.2%; 115±22 to 123±14°, P<0.001, respectively). Contractile improvement in basal IVS was correlated with pre-SAVR BSH (basal IVS/average LV wall thickness ratio or IVS-aorta angle: r=0.47 and 0.49, P<0.01, respectively). In contrast, BSH indices did not improve after TAVR. Conclusions: In patients with AS, SAVR as opposed to TAVR improves associated BSH and its functional impairment.