start-ver=1.4 cd-journal=joma no-vol=302 cd-vols= no-issue=8 article-no= start-page=113318 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2026 dt-pub=202608 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Proton pump rhodopsins for optogenetic manipulation of biological activities and beyond en-subtitle= kn-subtitle= en-abstract= kn-abstract=Water (H2O), the principal component of living organisms including humans, dissociates into H+ and OH- in aqueous environments, and the resulting H+ concentration determines both cellular pH and the proton motive force (PMF) across cellular membranes. These physicochemical parameters are fundamental regulators of a wide range of biological processes. Optogenetics enables the manipulation of biological and cellular functions using light, typically through the ectopic expression of microbial rhodopsins as photoreceptive proteins in target cells or organs. This review provides a comprehensive overview of optogenetic studies employing H+ pump rhodopsins in diverse biological systems and highlights their growing relevance to neuroscience, cell biology, bioengineering, and therapeutic research. Notably, optical control of H+ concentration allows the precise modulation of neural and non-neural activities in animals and bacteria, highlighting the broad applicability and significant potential of H+ pump rhodopsins for optogenetics. Based on previous and current studies, we discuss how further expansion of the molecular toolkit of H+ pump rhodopsins could enable increasingly fine-tuned manipulation of intracellular pH dynamics and PMF for probing cellular physiology and designing next-generation therapeutic strategies and consider emerging directions that extend beyond classical optogenetics toward the optical control of bioenergetic and chemical processes. en-copyright= kn-copyright= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=InokuchiMiyu en-aut-sei=Inokuchi en-aut-mei=Miyu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=H+ pump kn-keyword=H+ pump en-keyword=optogenetics kn-keyword=optogenetics en-keyword=pH kn-keyword=pH en-keyword=proton motive force kn-keyword=proton motive force en-keyword=retinal kn-keyword=retinal en-keyword=rhodopsin kn-keyword=rhodopsin END start-ver=1.4 cd-journal=joma no-vol=16 cd-vols= no-issue=23 article-no= start-page=5732 end-page=5738 dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=20250602 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Ultrafast Protein Dynamics Prior to Retinal Photoisomerization in Microbial Rhodopsins en-subtitle= kn-subtitle= en-abstract= kn-abstract=Rhodopsins, an important group of photoreceptor proteins, possess a retinal chromophore. It has long been believed that the photoisomerization of the chromophore is the initial event triggering its photocycle. However, we recently reported that protein structural changes around the chromophore precede photoisomerization in bacteriorhodopsin (BR). In this study, we performed deep-ultraviolet femtosecond stimulated Raman measurements for H+-pump rhodopsin (RxR) and photosensor rhodopsin (NpSRII) to investigate whether these ultrafast protein dynamics are common among rhodopsins. We observed that the protein structural changes occur within 0.2 ps after photoexcitation and precede the chromophore photoisomerization, similar to the case for BR. This strongly indicates that the protein structural change precedes the photoisomerization in rhodopsins, regardless of the difference in their origins and functions. Furthermore, we found that only limited protein changes occur on the time scale of the photoisomerization, suggesting that the protein environment is already optimized for the structural change of the chromophore. These observations raise the possibility that the ultrafast protein change arranges the environment around the chromophore to facilitate the photoisomerization. en-copyright= kn-copyright= en-aut-name=TaharaShinya en-aut-sei=Tahara en-aut-mei=Shinya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KuriharaRika en-aut-sei=Kurihara en-aut-mei=Rika kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KuramochiHikaru en-aut-sei=Kuramochi en-aut-mei=Hikaru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TakeuchiSatoshi en-aut-sei=Takeuchi en-aut-mei=Satoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=TaharaTahei en-aut-sei=Tahara en-aut-mei=Tahei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil=Molecular Spectroscopy Laboratory, RIKEN kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Molecular Spectroscopy Laboratory, RIKEN kn-affil= affil-num=5 en-affil=Molecular Spectroscopy Laboratory, RIKEN kn-affil= affil-num=6 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=7 en-affil=Molecular Spectroscopy Laboratory, RIKEN kn-affil= END start-ver=1.4 cd-journal=joma no-vol=22 cd-vols= no-issue=3 article-no= start-page=e220018 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=2025 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Origin of the unique topology of the triangular water cluster in <i>Rubrobacter xylanophilus</i> rhodopsin en-subtitle= kn-subtitle= en-abstract= kn-abstract=The crystal structure of Rubrobacter xylanophilus rhodopsin (RxR) reveals a triangular cluster of three water molecules (W413, W415, and W419) at the extracellular proton-release site, near Glu187 and Glu197. Using a quantum mechanical/molecular mechanical approach, we identified the structural nature of this unique water cluster. The triangular shape is best reproduced when all three water molecules are neutral H2O with protonated Glu187 and deprotonated Glu197. Attempts to place H3O+ at any of these water molecules result in spontaneous proton transfer to one of the acidic residues and significant distortion from the crystal structure. The plane defined by the triangular water cluster extends into the guanidinium plane of Arg71, with both aligned along the W413...W419 axis. This extended plane lies nearly perpendicular to a five-membered, ring-like H-bond network involving two carboxyl oxygen atoms from Glu187 and one from Glu197. The resulting bipartite planar architecture, defined by the water triangle, Arg71, and the Glu187/Glu197 network may reflect the exceptional thermal stability in RxR. en-copyright= kn-copyright= en-aut-name=NojiTomoyasu en-aut-sei=Noji en-aut-mei=Tomoyasu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TsujimuraMasaki en-aut-sei=Tsujimura en-aut-mei=Masaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SaitoKeisuke en-aut-sei=Saito en-aut-mei=Keisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=IshikitaHiroshi en-aut-sei=Ishikita en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo kn-affil= affil-num=2 en-affil=Department of Advanced Interdisciplinary Studies, The University of Tokyo kn-affil= affil-num=3 en-affil=Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo kn-affil= affil-num=4 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=5 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=6 en-affil=Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo kn-affil= en-keyword=microbial rhodopsin kn-keyword=microbial rhodopsin en-keyword=proton transfer pathway kn-keyword=proton transfer pathway en-keyword=H3O+ kn-keyword=H3O+ en-keyword=pKa kn-keyword=pKa en-keyword=proton release group kn-keyword=proton release group END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=20251104 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Optogenetic Cancer Therapy Using the Light-Driven Outward Proton Pump Rhodopsin Archaerhodopsin-3 (AR3) en-subtitle= kn-subtitle= en-abstract= kn-abstract=Medicines used for cancer treatment often cause serious side effects by damaging normal cells due to nonspecific diffusion. To address this issue, we previously developed an optical method to induce apoptotic cell death via intracellular pH alkalinization using the outward proton pump rhodopsin, Archaerhodopsin-3 (AR3) in various noncancer model cells in vitro and in vivo. In this study, we applied this method to cancer cells and tumors to evaluate its potential as an anticancer therapeutic strategy. First, we confirmed that AR3-expressing murine cancer cell lines (MC38, B16F10) showed apoptotic cell death upon green light irradiation, as indicated by increased levels of cell death and apoptosis-related markers. Next, we established stable AR3-expressing MC38 and B16F10 cells by using viral vectors. When these AR3-expressing cells were subcutaneously transplanted into C57BL/6 mice, the resulting tumors initially grew at a rate comparable to that of control tumors lacking AR3 expression or light stimulation. However, upon green light irradiation, AR3-expressing tumors exhibited either a marked reduction in size or significantly suppressed growth, accompanied by the induction of apoptosis signals and decreased proliferation signals. These results demonstrate that AR3-mediated cell death has potent antitumor effects both in vitro and in vivo. This optical method thus holds promise as a novel cancer therapy with potentially reduced side effects. en-copyright= kn-copyright= en-aut-name=NakaoShin en-aut-sei=Nakao en-aut-mei=Shin kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SatoKeita en-aut-sei=Sato en-aut-mei=Keita kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KemmotsuNaoya en-aut-sei=Kemmotsu en-aut-mei=Naoya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=OhuchiHideyo en-aut-sei=Ohuchi en-aut-mei=Hideyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=TogashiYosuke en-aut-sei=Togashi en-aut-mei=Yosuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=5 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=6 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=7 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=18 cd-vols= no-issue=1 article-no= start-page=wrae175 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=202401 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Cyanorhodopsin-II represents a yellow-absorbing proton-pumping rhodopsin clade within cyanobacteria en-subtitle= kn-subtitle= en-abstract= kn-abstract=Microbial rhodopsins are prevalent in many cyanobacterial groups as a light-energy-harvesting system in addition to the photosynthetic system. It has been suggested that this dual system allows efficient capture of sunlight energy using complementary ranges of absorption wavelengths. However, the diversity of cyanobacterial rhodopsins, particularly in accumulated metagenomic data, remains underexplored. Here, we used a metagenomic mining approach, which led to the identification of a novel rhodopsin clade unique to cyanobacteria, cyanorhodopsin-II (CyR-II). CyR-IIs function as light-driven outward H+ pumps. CyR-IIs, together with previously identified cyanorhodopsins (CyRs) and cyanobacterial halorhodopsins (CyHRs), constitute cyanobacterial ion-pumping rhodopsins (CyipRs), a phylogenetically distinct family of rhodopsins. The CyR-II clade is further divided into two subclades, YCyR-II and GCyR-II, based on their specific absorption wavelength. YCyR-II absorbed yellow light (ămax?=?570 nm), whereas GCyR-II absorbed green light (ămax?=?550 nm). X-ray crystallography and mutational analysis revealed that the difference in absorption wavelengths is attributable to slight changes in the side chain structure near the retinal chromophore. The evolutionary trajectory of cyanobacterial rhodopsins suggests that the function and light-absorbing range of these rhodopsins have been adapted to a wide range of habitats with variable light and environmental conditions. Collectively, these findings shed light on the importance of rhodopsins in the evolution and environmental adaptation of cyanobacteria. en-copyright= kn-copyright= en-aut-name=Hasegawa-TakanoMasumi en-aut-sei=Hasegawa-Takano en-aut-mei=Masumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=HosakaToshiaki en-aut-sei=Hosaka en-aut-mei=Toshiaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NishimuraYosuke en-aut-sei=Nishimura en-aut-mei=Yosuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KuriharaMarie en-aut-sei=Kurihara en-aut-mei=Marie kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NakajimaYu en-aut-sei=Nakajima en-aut-mei=Yu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=Ishizuka-KatsuraYoshiko en-aut-sei=Ishizuka-Katsura en-aut-mei=Yoshiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=Kimura-SomeyaTomomi en-aut-sei=Kimura-Someya en-aut-mei=Tomomi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=ShirouzuMikako en-aut-sei=Shirouzu en-aut-mei=Mikako kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=YoshizawaSusumu en-aut-sei=Yoshizawa en-aut-mei=Susumu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= affil-num=1 en-affil=Atmosphere and Ocean Research Institute, The University of Tokyo kn-affil= affil-num=2 en-affil=Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research kn-affil= affil-num=3 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Atmosphere and Ocean Research Institute, The University of Tokyo kn-affil= affil-num=5 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=6 en-affil=Atmosphere and Ocean Research Institute, The University of Tokyo kn-affil= affil-num=7 en-affil=Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research kn-affil= affil-num=8 en-affil=Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research kn-affil= affil-num=9 en-affil=Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research kn-affil= affil-num=10 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=11 en-affil=Atmosphere and Ocean Research Institute, The University of Tokyo kn-affil= en-keyword=cyanobacteria kn-keyword=cyanobacteria en-keyword=microbial rhodopsin kn-keyword=microbial rhodopsin en-keyword=ecology kn-keyword=ecology en-keyword=evolution kn-keyword=evolution END start-ver=1.4 cd-journal=joma no-vol=301 cd-vols= no-issue=7 article-no= start-page=110291 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=202507 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=A repertoire of visible light?sensitive opsins in the deep-sea hydrothermal vent shrimp Rimicaris hybisae en-subtitle= kn-subtitle= en-abstract= kn-abstract=Unlike terrestrial environments, where humans reside, there is no sunlight in the deep sea. Instead, dim visible light from black-body radiation and bioluminescence illuminates hydrothermal vent areas in the deep sea. A deep-sea hydrothermal vent shrimp, Rimicaris hybisae, is thought to detect this dim light using its enlarged dorsal eye; however, the molecular basis of its photoreception remains unexplored. Here, we characterized the molecular properties of opsins, universal photoreceptive proteins in animals, found in R. hybisae. Transcriptomic analysis identified six opsins: three Gq-coupled opsins, one Opn3, one Opn5, and one peropsin. Functional analysis revealed that five of these opsins exhibited light-dependent G protein activity, whereas peropsin exhibited the ability to convert all-trans-retinal to 11-cis-retinal like photoisomerases. Notably, all the R. hybisae opsins, including Opn5, convergently show visible light sensitivity (around 457?517 nm), whereas most opsins categorized as Opn5 have been demonstrated to be UV sensitive. Mutational analysis revealed that the unique visible light sensitivity of R. hybisae Opn5 is achieved through the stabilization of a protonated Schiff base by a counterion residue at position 83 (Asp83), which differs from the position identified in other opsins. These findings suggest that the vent shrimp R. hybisae has adapted its photoreceptive devices to dim deep-sea hydrothermal light by selectively maintaining a repertoire of visible light?sensitive opsins, including the uniquely tuned Opn5. en-copyright= kn-copyright= en-aut-name=NagataYuya en-aut-sei=Nagata en-aut-mei=Yuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MiyamotoNorio en-aut-sei=Miyamoto en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SatoKeita en-aut-sei=Sato en-aut-mei=Keita kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NishimuraYosuke en-aut-sei=Nishimura en-aut-mei=Yosuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TaniokaYuki en-aut-sei=Tanioka en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=YamanakaYuji en-aut-sei=Yamanaka en-aut-mei=Yuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=YoshizawaSusumu en-aut-sei=Yoshizawa en-aut-mei=Susumu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=TakahashiKuto en-aut-sei=Takahashi en-aut-mei=Kuto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=ObayashiKohei en-aut-sei=Obayashi en-aut-mei=Kohei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=TsukamotoHisao en-aut-sei=Tsukamoto en-aut-mei=Hisao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=TakaiKen en-aut-sei=Takai en-aut-mei=Ken kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=OhuchiHideyo en-aut-sei=Ohuchi en-aut-mei=Hideyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=YamashitaTakahiro en-aut-sei=Yamashita en-aut-mei=Takahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=14 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=15 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Institute for Extra-Cutting-Edge Science and Technology Avant-Garde Research (X-Star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC) kn-affil= affil-num=3 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Research Center for Bioscience and Nanoscience (CeBN), Research Institute for Marine Resources Utilization, Japan Agency for Marine-Earth Science and Technology (JAMSTEC) kn-affil= affil-num=5 en-affil=School of Pharmaceutical Sciences, Okayama University kn-affil= affil-num=6 en-affil=School of Pharmaceutical Sciences, Okayama University kn-affil= affil-num=7 en-affil=Atmosphere and Ocean Research Institute, The University of Tokyo kn-affil= affil-num=8 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=9 en-affil=Department of Biology, Graduate School of Science, Kobe University kn-affil= affil-num=10 en-affil=Department of Biology, Graduate School of Science, Kobe University kn-affil= affil-num=11 en-affil=Institute for Extra-Cutting-Edge Science and Technology Avant-Garde Research (X-Star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC) kn-affil= affil-num=12 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=13 en-affil=Department of Biophysics, Graduate School of Science, Kyoto University kn-affil= affil-num=14 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=15 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=rhodopsin kn-keyword=rhodopsin en-keyword=opsin kn-keyword=opsin en-keyword=G protein?coupled receptor kn-keyword=G protein?coupled receptor en-keyword=signal transduction kn-keyword=signal transduction en-keyword=photoreceptor kn-keyword=photoreceptor en-keyword=vision kn-keyword=vision en-keyword=photobiology kn-keyword=photobiology en-keyword=vent shrimp kn-keyword=vent shrimp en-keyword=deep sea kn-keyword=deep sea en-keyword=molecular evolution kn-keyword=molecular evolution END start-ver=1.4 cd-journal=joma no-vol=301 cd-vols= no-issue=4 article-no= start-page=108334 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=202504 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Roles of basic amino acid residues in substrate binding and transport of the light-driven anion pump Synechocystis halorhodopsin (SyHR) en-subtitle= kn-subtitle= en-abstract= kn-abstract=Microbial rhodopsins are photoreceptive seventransmembrane a-helical proteins, many of which function as ion transporters, primarily for small monovalent ions such as Na+, K+, Cl-, Br-, and I-. Synechocystis halorhodopsin (SyHR), identified from the cyanobacterium Synechocystis sp. PCC 7509, uniquely transports the polyatomic divalent SO42- inward, in addition to monovalent anions (Cl- and Br-). In this study, we conducted alanine-scanning mutagenesis on twelve basic amino acid residues to investigate the anion transport mechanism of SyHR. We quantitatively evaluated the Cl-and SO42- transport activities of the WT SyHR and its mutants. The results showed a strong correlation between the Cl-and SO42- transport activities among them (R = 0.94), suggesting a shared pathway for both anions. Notably, the R71A mutation selectively abolished SO42- transport activity while maintaining Cl- transport, whereas the H167A mutation significantly impaired both Cl-and SO42- transport. Furthermore, spectroscopic analysis revealed that the R71A mutant lost its ability to bind SO42- due to the absence of a positive charge, while the H167A mutant failed to accumulate the O intermediate during the photoreaction cycle (photocycle) due to reduced hydrophilicity. Additionally, computational analysis revealed the SO42- binding modes and clarified the roles of residues involved in its binding around the retinal chromophore. Based on these findings and previous structural information, we propose that the positive charge and hydrophilicity of Arg71 and His167 are crucial for the formation of the characteristic initial and transient anion-binding site of SyHR, enabling its unique ability to bind and transport both Cl-and SO42-. en-copyright= kn-copyright= en-aut-name=NakamaMasaki en-aut-sei=Nakama en-aut-mei=Masaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NojiTomoyasu en-aut-sei=Noji en-aut-mei=Tomoyasu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YoshizawaSusumu en-aut-sei=Yoshizawa en-aut-mei=Susumu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=IshikitaHiroshi en-aut-sei=Ishikita en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Department of Applied Chemistry, The University of Tokyo kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Atmosphere and Ocean Research Institute, The University of Tokyo kn-affil= affil-num=5 en-affil=Department of Applied Chemistry, The University of Tokyo kn-affil= affil-num=6 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=microbial rhodopsin kn-keyword=microbial rhodopsin en-keyword=anion transport kn-keyword=anion transport en-keyword=retinal kn-keyword=retinal en-keyword=membrane protein kn-keyword=membrane protein en-keyword=photobiology kn-keyword=photobiology END start-ver=1.4 cd-journal=joma no-vol=47 cd-vols= no-issue=10 article-no= start-page=1600 end-page=1609 dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20241001 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Molecular Diversity of Photosensitive Protein Opsins and Their High Potential for Optogenetic Applications en-subtitle= kn-subtitle= en-abstract= kn-abstract=Because G protein coupled receptors (GPCRs) represent the largest family of drug targets in clinical trials, GPCR signaling cascades are closely related to various physiological phenomena, attracting significant attention in pharmaceutical science. Opsins (also known as animal rhodopsins) are photoreceptive proteins containing retinal as a chromophore, which function as GPCRs and underlie the molecular basis of photoreception in animals. Recently, opsins have been progressively applied in an innovative technology called optogenetics to regulate biological activities using light. A wide variety of opsins have been identified in metazoans and characterized at the molecular and physiological levels, providing a foundation for their optogenetic applications. In this review, I briefly introduce the diversity of opsins in terms of their molecular functions, including G protein selectivity and photoreaction properties. This diversity provides a significant advantage for optically manipulating a wide variety of GPCR signaling cascades with high temporal resolution. Additionally, I discuss the rich array of opsin-based optogenetic tools used to control various physiological processes and their potential as therapeutic tools for vision restoration. Based on the introduction, I expect that the optogenetic approach will offer powerful tools to provide valuable insights into the molecular mechanisms of various physiological phenomena and next-generation treatment options for diseases beyond the capacity of traditional drugs. en-copyright= kn-copyright= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= affil-num=1 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=128 cd-vols= no-issue=27 article-no= start-page=6509 end-page=6517 dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20240701 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Bidirectional Optical Control of Proton Motive Force in Escherichia coli Using Microbial Rhodopsins en-subtitle= kn-subtitle= en-abstract= kn-abstract=Proton (H+) motive force (PMF) serves as the energy source for the flagellar motor rotation, crucial for microbial motility. Here, to control PMF using light, we introduced light-driven inward and outward proton pump rhodopsins, RmXeR and AR3, into Escherichia coli. The motility of E. coli cells expressing RmXeR and AR3 significantly decreased and increased upon illumination, respectively. Tethered cell experiments revealed that, upon illumination, the torque of the flagellar motor decreased to nearly zero (28 pN nm) with RmXeR, while it increased to 1170 pN nm with AR3. These alterations in PMF correspond to +146 mV (RmXeR) and ?140 mV (AR3), respectively. Thus, bidirectional optical control of PMF in E. coli was successfully achieved by using proton pump rhodopsins. This system holds a potential for enhancing our understanding of the roles of PMF in various biological functions. en-copyright= kn-copyright= en-aut-name=NakanishiKotaro en-aut-sei=Nakanishi en-aut-mei=Kotaro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SowaYoshiyuki en-aut-sei=Sowa en-aut-mei=Yoshiyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Department of Frontier Bioscience and Research Center for Micro-Nano Technology, Hosei University kn-affil= affil-num=4 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=3 cd-vols= no-issue=1 article-no= start-page=101046 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2022 dt-pub=20220318 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Expression of microbial rhodopsins in Escherichia coli and their extraction and purification using styrene-maleic acid copolymers en-subtitle= kn-subtitle= en-abstract= kn-abstract=Microbial rhodopsins are photoreceptive membrane proteins showing various light-dependent biological activities. Styrene-maleic acid (SMA) copolymers spontaneously form nanoscale lipid particles containing membrane proteins and associated lipids without detergent, and can be used to characterize membrane molecules. Here, we provide a protocol to functionally express a thermally stable rhodopsin, Rubrobacter xylanophilus rhodopsin, and an unstable rhodopsin, Halobacterium salinarum sensory rhodopsin I, in Escherichia coli. We then describe the preparation of SMA and the extraction and purification of rhodopsin molecules using SMA.
For complete details on the use and execution of this protocol, please refer to Ueta et al. (2020). en-copyright= kn-copyright= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=677 cd-vols= no-issue= article-no= start-page=1 end-page=5 dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20231015 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Demonstration of iodide-dependent UVA-triggered growth inhibition in Saccharomyces cerevisiae cells and identification of its suppressive molecules en-subtitle= kn-subtitle= en-abstract= kn-abstract=Upon white light illumination, the growth of the budding yeast Saccharomyces cerevisiae was extremely impaired only in the presence of iodide ions, but not fluoride, chloride and bromide ions. Action spectroscopy revealed that the maximum wavelength of the light is around at 373 nm, corresponding to the UVA region. Using a genetic approach, several genes, including OPY1, HEM1, and PAU11, were identified as suppressors of this growth inhibition. This iodide-dependent UVA-triggered growth inhibition method, along with its suppressive molecules, would be beneficial for understanding cell growth processes in eukaryotes and can be utilized for medium sterilization using UVA light. en-copyright= kn-copyright= en-aut-name=OnoRyota en-aut-sei=Ono en-aut-mei=Ryota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SaekiNozomu en-aut-sei=Saeki en-aut-mei=Nozomu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MoriyaHisao en-aut-sei=Moriya en-aut-mei=Hisao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=3 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=5 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=UVA kn-keyword=UVA en-keyword=Saccharomyces cerevisiae kn-keyword=Saccharomyces cerevisiae en-keyword=Iodide kn-keyword=Iodide en-keyword=Growth inhibition kn-keyword=Growth inhibition en-keyword=Suppressive molecule kn-keyword=Suppressive molecule END start-ver=1.4 cd-journal=joma no-vol=14 cd-vols= no-issue=1 article-no= start-page=1730 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20230403 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Structure and mechanism of oxalate transporter OxlT in an oxalate-degrading bacterium in the gut microbiota en-subtitle= kn-subtitle= en-abstract= kn-abstract=An oxalate-degrading bacterium in the gut microbiota absorbs food-derived oxalate to use this as a carbon and energy source, thereby reducing the risk of kidney stone formation in host animals. The bacterial oxalate transporter OxlT selectively uptakes oxalate from the gut to bacterial cells with a strict discrimination from other nutrient carboxylates. Here, we present crystal structures of oxalate-bound and ligand-free OxlT in two distinct conformations, occluded and outward-facing states. The ligand-binding pocket contains basic residues that form salt bridges with oxalate while preventing the conformational switch to the occluded state without an acidic substrate. The occluded pocket can accommodate oxalate but not larger dicarboxylates, such as metabolic intermediates. The permeation pathways from the pocket are completely blocked by extensive interdomain interactions, which can be opened solely by a flip of a single side chain neighbouring the substrate. This study shows the structural basis underlying metabolic interactions enabling favourable symbiosis. en-copyright= kn-copyright= en-aut-name=Jaunet-LaharyTitouan en-aut-sei=Jaunet-Lahary en-aut-mei=Titouan kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=ShimamuraTatsuro en-aut-sei=Shimamura en-aut-mei=Tatsuro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HayashiMasahiro en-aut-sei=Hayashi en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NomuraNorimichi en-aut-sei=Nomura en-aut-mei=Norimichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=HirasawaKouta en-aut-sei=Hirasawa en-aut-mei=Kouta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=ShimizuTetsuya en-aut-sei=Shimizu en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=YamashitaMasao en-aut-sei=Yamashita en-aut-mei=Masao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=TsutsumiNaotaka en-aut-sei=Tsutsumi en-aut-mei=Naotaka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=SuehiroYuta en-aut-sei=Suehiro en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=TamuraTakashi en-aut-sei=Tamura en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=IwanariHiroko en-aut-sei=Iwanari en-aut-mei=Hiroko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= en-aut-name=HamakuboTakao en-aut-sei=Hamakubo en-aut-mei=Takao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=14 ORCID= en-aut-name=IwataSo en-aut-sei=Iwata en-aut-mei=So kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=15 ORCID= en-aut-name=OkazakiKei-Ichi en-aut-sei=Okazaki en-aut-mei=Kei-Ichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=16 ORCID= en-aut-name=HiraiTeruhisa en-aut-sei=Hirai en-aut-mei=Teruhisa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=17 ORCID= en-aut-name=YamashitaAtsuko en-aut-sei=Yamashita en-aut-mei=Atsuko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=18 ORCID= affil-num=1 en-affil=Research Center for Computational Science, Institute for Molecular Science, National Institutes of Natural Sciences kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Kyoto University kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Medicine, Kyoto University kn-affil= affil-num=5 en-affil=Graduate School of Medicine, Kyoto University kn-affil= affil-num=6 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=7 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=8 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=9 en-affil=School of Pharmaceutical Sciences, Okayama University kn-affil= affil-num=10 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=11 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=12 en-affil=Graduate School of Environmental and Life Sciences, Okayama University kn-affil= affil-num=13 en-affil=Research Center for Advanced Science and Technology, The University of Tokyo kn-affil= affil-num=14 en-affil=Research Center for Advanced Science and Technology, The University of Tokyo kn-affil= affil-num=15 en-affil=Graduate School of Medicine, Kyoto University kn-affil= affil-num=16 en-affil=Research Center for Computational Science, Institute for Molecular Science, National Institutes of Natural Sciences kn-affil= affil-num=17 en-affil=RIKEN SPring-8 Center kn-affil= affil-num=18 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=13 cd-vols= no-issue=1 article-no= start-page=6974 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20230428 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=A blue-shifted anion channelrhodopsin from the Colpodellida alga Vitrella brassicaformis en-subtitle= kn-subtitle= en-abstract= kn-abstract=Microbial rhodopsins, a family of photoreceptive membrane proteins containing the chromophore retinal, show a variety of light-dependent molecular functions. Channelrhodopsins work as light-gated ion channels and are widely utilized for optogenetics, which is a method for controlling neural activities by light. Since two cation channelrhodopsins were identified from the chlorophyte alga Chlamydomonas reinhardtii, recent advances in genomic research have revealed a wide variety of channelrhodopsins including anion channelrhodopsins (ACRs), describing their highly diversified molecular properties (e.g., spectral sensitivity, kinetics and ion selectivity). Here, we report two channelrhodopsin-like rhodopsins from the Colpodellida alga Vitrella brassicaformis, which are phylogenetically distinct from the known channelrhodopsins. Spectroscopic and electrophysiological analyses indicated that these rhodopsins are green- and blue-sensitive pigments (lambda(max) = similar to 550 and similar to 440 nm) that exhibit light-dependent ion channeling activities. Detailed electrophysiological analysis revealed that one of them works as a monovalent anion (Cl-, Br- and NO3-) channel and we named it V. brassicaformis anion channelrhodopsin-2, VbACR2. Importantly, the absorption maximum of VbACR2 (similar to 440 nm) is blue-shifted among the known ACRs. Thus, we identified the new blue-shifted ACR, which leads to the expansion of the molecular diversity of ACRs. en-copyright= kn-copyright= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KawanishiShiho en-aut-sei=Kawanishi en-aut-mei=Shiho kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NishimuraYosuke en-aut-sei=Nishimura en-aut-mei=Yosuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=HasegawaMasumi en-aut-sei=Hasegawa en-aut-mei=Masumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=NakaoShin en-aut-sei=Nakao en-aut-mei=Shin kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NagataYuya en-aut-sei=Nagata en-aut-mei=Yuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=YoshizawaSusumu en-aut-sei=Yoshizawa en-aut-mei=Susumu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Research Center for Bioscience and Nanoscience (CeBN), Research Institute for Marine Resources Utilization, Japan Agency for Marine-Earth Science and Technology (JAMSTEC) kn-affil= affil-num=4 en-affil=Institute for Extra?Cutting?Edge Science and Technology Avant?Garde Research (X?Star) kn-affil= affil-num=5 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=6 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=7 en-affil=Atmosphere and Ocean Research Institute, The University of Tokyo kn-affil= affil-num=8 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=59 cd-vols= no-issue=49 article-no= start-page=7591 end-page=7594 dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=2023 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Development of light-induced disruptive liposomes (LiDL) as a photoswitchable carrier for intracellular substance delivery en-subtitle= kn-subtitle= en-abstract= kn-abstract=Light-driven inward proton pump rhodopsin RmXeR was embedded in pH-sensitive liposomes. Substance release from the proteoliposomes was observed following light illumination both in vitro and in cells, indicating the successful production of light-induced disruptive liposomes (LiDL). Thus, LiDL is a photoswitchable carrier utilized for intracellular substance delivery. en-copyright= kn-copyright= en-aut-name=TsuneishiTaichi en-aut-sei=Tsuneishi en-aut-mei=Taichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KubotaFumika en-aut-sei=Kubota en-aut-mei=Fumika kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=HarashimaHideyoshi en-aut-sei=Harashima en-aut-mei=Hideyoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=YamadaYuma en-aut-sei=Yamada en-aut-mei=Yuma kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Faculty of Pharmaceutical Sciences, Hokkaido University kn-affil= affil-num=4 en-affil=Faculty of Pharmaceutical Sciences, Hokkaido University kn-affil= affil-num=5 en-affil=Faculty of Pharmaceutical Sciences, Hokkaido University kn-affil= affil-num=6 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=13 cd-vols= no-issue=11 article-no= start-page=7222 end-page=7224 dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20230306 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Correction: Convergent evolution of animal and microbial rhodopsins en-subtitle= kn-subtitle= en-abstract= kn-abstract=Correction for 'Convergent evolution of animal and microbial rhodopsins' by Keiichi Kojima et al., RSC Adv., 2023, 13, 5367-5381, https://doi.org/10.1039/D2RA07073A. en-copyright= kn-copyright= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=13 cd-vols= no-issue=8 article-no= start-page=5367 end-page=5381 dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20230213 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Convergent evolution of animal and microbial rhodopsins en-subtitle= kn-subtitle= en-abstract= kn-abstract=Rhodopsins, a family of photoreceptive membrane proteins, contain retinal as a chromophore and were firstly identified as reddish pigments from frog retina in 1876. Since then, rhodopsin-like proteins have been identified mainly from animal eyes. In 1971, a rhodopsin-like pigment was discovered from the archaeon Halobacterium salinarum and named bacteriorhodopsin. While it was believed that rhodopsin- and bacteriorhodopsin-like proteins were expressed only in animal eyes and archaea, respectively, before the 1990s, a variety of rhodopsin-like proteins (called animal rhodopsins or opsins) and bacteriorhodopsin-like proteins (called microbial rhodopsins) have been progressively identified from various tissues of animals and microorganisms, respectively. Here, we comprehensively introduce the research conducted on animal and microbial rhodopsins. Recent analysis has revealed that the two rhodopsin families have common molecular properties, such as the protein structure (i.e., 7-transmembrane structure), retinal structure (i.e., binding ability to cis- and trans-retinal), color sensitivity (i.e., UV- and visible-light sensitivities), and photoreaction (i.e., triggering structural changes by light and heat), more than what was expected at the early stages of rhodopsin research. Contrastingly, their molecular functions are distinctively different (e.g., G protein-coupled receptors and photoisomerases for animal rhodopsins and ion transporters and phototaxis sensors for microbial rhodopsins). Therefore, based on their similarities and dissimilarities, we propose that animal and microbial rhodopsins have convergently evolved from their distinctive origins as multi-colored retinal-binding membrane proteins whose activities are regulated by light and heat but independently evolved for different molecular and physiological functions in the cognate organism. en-copyright= kn-copyright= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=8 cd-vols= no-issue= article-no= start-page=4826 end-page=4834 dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20230125 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Detection of Membrane Potential-Dependent Rhodopsin Fluorescence Using Low-Intensity Light Emitting Diode for Long-Term Imaging en-subtitle= kn-subtitle= en-abstract= kn-abstract=Microbial rhodopsin is a family of photoreceptive membrane proteins that commonly consist of a seven-transmembrane domain and a derivative of vitamin-A, retinal, as a chromophore. In 2011, archaeorhodopsin-3 (AR3) was shown to exhibit voltage-dependent fluorescence changes in mammalian cells. Since then, AR3 and its variants have been used as genetically encoded voltage indicators, in which mostly intense laser stimulation (1-1000 W/cm(2)) is used for the detection of dim fluorescence of rhodopsin, leading to high spatiotemporal resolution. However, intense laser stimulation potentially causes serious cell damage, particularly during long-term imaging over minutes. In this study, we present the successful detection of voltage-sensitive fluorescence of AR3 and its high fluorescence mutant Archon1 in a variety of mammalian cell lines using low-intensity light emitting diode stimulation (0.15 W/cm2) with long exposure time (500 ms). The detection system enables real-time imaging of drug-induced slow changes in voltage within the cells for minutes harmlessly and without fluorescence bleaching. Therefore, we demonstrate a method to quantitatively understand the dynamics of slow changes in membrane voltage on long time scales. en-copyright= kn-copyright= en-aut-name=KawanishiShiho en-aut-sei=Kawanishi en-aut-mei=Shiho kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=ShibukawaAtsushi en-aut-sei=Shibukawa en-aut-mei=Atsushi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SakamotoMasayuki en-aut-sei=Sakamoto en-aut-mei=Masayuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Department of Optical Neural and Molecular Physiology, Graduate School of Biostudies kn-affil= affil-num=5 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Faculty of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= END start-ver=1.4 cd-journal=joma no-vol=8 cd-vols= no-issue= article-no= start-page=794948 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20211220 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Exploring the Retinal Binding Cavity of Archaerhodopsin-3 by Replacing the Retinal Chromophore With a Dimethyl Phenylated Derivative en-subtitle= kn-subtitle= en-abstract= kn-abstract=Rhodopsins act as photoreceptors with their chromophore retinal (vitamin-A aldehyde) and they regulate light-dependent biological functions. Archaerhodopsin-3 (AR3) is an outward proton pump that has been widely utilized as a tool for optogenetics, a method for controlling cellular activity by light. To characterize the retinal binding cavity of AR3, we synthesized a dimethyl phenylated retinal derivative, (2E,4E,6E,8E)-9-(2,6-Dimethylphenyl)-3,7-dimethylnona-2,4,6,8-tetraenal (DMP-retinal). QM/MM calculations suggested that DMP-retinal can be incorporated into the opsin of AR3 (archaeopsin-3, AO3). Thus, we introduced DMP-retinal into AO3 to obtain the non-natural holoprotein (AO3-DMP) and compared some molecular properties with those of AO3 with the natural A1-retinal (AO3-A1) or AR3. Light-induced pH change measurements revealed that AO3-DMP maintained slow outward proton pumping. Noteworthy, AO3-DMP had several significant changes in its molecular properties compared with AO3-A1 as follows; 1) spectroscopic measurements revealed that the absorption maximum was shifted from 556 to 508 nm and QM/MM calculations showed that the blue-shift was due to the significant increase in the HOMO-LUMO energy gap of the chromophore with the contribution of some residues around the chromophore, 2) time-resolved spectroscopic measurements revealed the photocycling rate was significantly decreased, and 3) kinetical spectroscopic measurements revealed the sensitivity of the chromophore binding Schiff base to attack by hydroxylamine was significantly increased. The QM/MM calculations show that a cavity space is present at the aromatic ring moiety in the AO3-DMP structure whereas it is absent at the corresponding beta-ionone ring moiety in the AO3-A1 structure. We discuss these alterations of the difference in interaction between the natural A1-retinal and the DMP-retinal with binding cavity residues. en-copyright= kn-copyright= en-aut-name=TsuneishiTaichi en-aut-sei=Tsuneishi en-aut-mei=Taichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiMasataka en-aut-sei=Takahashi en-aut-mei=Masataka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TsujimuraMasaki en-aut-sei=Tsujimura en-aut-mei=Masaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=IshikitaHiroshi en-aut-sei=Ishikita en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=TakeuchiYasuo en-aut-sei=Takeuchi en-aut-mei=Yasuo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil=Laboratory of Biophysical Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Laboratory of Synthetic and Medicinal Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Department of Applied Chemistry, The University of Tokyo kn-affil= affil-num=4 en-affil=Laboratory of Biophysical Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=5 en-affil=Department of Applied Chemistry, The University of Tokyo kn-affil= affil-num=6 en-affil=Laboratory of Synthetic and Medicinal Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=7 en-affil=Laboratory of Biophysical Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=retinal kn-keyword=retinal en-keyword=rhodopsin kn-keyword=rhodopsin en-keyword=proton pump kn-keyword=proton pump en-keyword=derivative kn-keyword=derivative en-keyword=photoreceptor kn-keyword=photoreceptor END start-ver=1.4 cd-journal=joma no-vol=10 cd-vols= no-issue= article-no= start-page=e72264 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20211221 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Proton transfer pathway in anion channelrhodopsin-1 en-subtitle= kn-subtitle= en-abstract= kn-abstract=Anion channelrhodopsin from Guillardia theta (GtACR1) has Asp234 (3.2 angstrom) and Glu68 (5.3 angstrom) near the protonated Schiff base. Here, we investigate mutant GtACR1s (e.g., E68Q/D234N) expressed in HEK293 cells. The influence of the acidic residues on the absorption wavelengths was also analyzed using a quantum mechanical/molecular mechanical approach. The calculated protonation pattern indicates that Asp234 is deprotonated and Glu68 is protonated in the original crystal structures. The D234E mutation and the E68Q/D234N mutation shorten and lengthen the measured and calculated absorption wavelengths, respectively, which suggests that Asp234 is deprotonated in the wild-type GtACR1. Molecular dynamics simulations show that upon mutation of deprotonated Asp234 to asparagine, deprotonated Glu68 reorients toward the Schiff base and the calculated absorption wavelength remains unchanged. The formation of the proton transfer pathway via Asp234 toward Glu68 and the disconnection of the anion conducting channel are likely a basis of the gating mechanism. en-copyright= kn-copyright= en-aut-name=TsujimuraMasaki en-aut-sei=Tsujimura en-aut-mei=Masaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KawanishiShiho en-aut-sei=Kawanishi en-aut-mei=Shiho kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=IshikitaHiroshi en-aut-sei=Ishikita en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Department of Applied Chemistry, The University of Tokyo kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=5 en-affil=Department of Applied Chemistry, The University of Tokyo kn-affil= END start-ver=1.4 cd-journal=joma no-vol=44 cd-vols= no-issue=10 article-no= start-page=1357 end-page=1363 dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=2021101 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Microbial Rhodopsins as Multi-functional Photoreactive Membrane Proteins for Optogenetics en-subtitle= kn-subtitle= en-abstract= kn-abstract=In life science research, methods to control biological activities with stimuli such as light, heat, pressure and chemicals have been widely utilized to understand their molecular mechanisms. The knowledge obtained by those methods has built a basis for the development of medicinal products. Among those various stimuli, light has the advantage of a high spatiotemporal resolution that allows for the precise control of biological activities. Photoactive membrane protein rhodopsins from microorganisms (called microbial rhodopsins) absorb visible light and that light absorption triggers the trans?cis photoisomerization of the chromophore retinal, leading to various functions such as ion pumps, ion channels, transcriptional regulators and enzymes. In addition to their biological significance, microbial rhodopsins are widely utilized as fundamental molecular tools for optogenetics, a method to control biological activities by light. In this review, we briefly introduce the molecular basis of representative rhodopsin molecules and their applications for optogenetics. Based on those examples, we discuss the high potential of rhodopsin-based optogenetics tools for basic and clinical research in pharmaceutical sciences. en-copyright= kn-copyright= en-aut-name=NakaoShin en-aut-sei=Nakao en-aut-mei=Shin kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SudoYuki en-aut-sei=Sudo en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil=Division of Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Division of Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Division of Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=rhodopsin kn-keyword=rhodopsin en-keyword=optogenetics kn-keyword=optogenetics en-keyword=retinal kn-keyword=retinal en-keyword=signal transduction kn-keyword=signal transduction END start-ver=1.4 cd-journal=joma no-vol=141 cd-vols= no-issue=10 article-no= start-page=1155 end-page=1160 dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=2021101 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=Biophysical and Biochemical Research of Animal Rhodopsins kn-title=ŒõŽó—eƒ^ƒ“ƒpƒNŽ¿EƒƒhƒvƒVƒ“‚̶•¨•¨—‰»ŠwŒ¤‹† en-subtitle= kn-subtitle= en-abstract= kn-abstract=Opsins (also called animal rhodopsins) are universal photoreceptive proteins that provide the molecular basis of visual and nonvisual photoreception in animals, including humans. Opsins consist of seven helical a-transmembrane domains and use retinal, a derivative of vitamin A, as a chromophore. In many opsins, light absorption triggers photoisomerization from 11-cis retinal to all-trans retinal, resulting in activation via dynamic structural changes in the protein moiety. Activated opsins stimulate cognate trimeric G proteins to induce signal transduction cascades in cells. Recently, molecular and physiological analyses of diverse opsins have progressively advanced. This review introduces the molecular basis and physiological unctions of opsins. Based on the functions of opsins, I will discuss the potential of opsins as target molecules to treat and prevent visual and nonvisual diseases such as sleep disorder and depression. en-copyright= kn-copyright= en-aut-name=KojimaKeiichi en-aut-sei=Kojima en-aut-mei=Keiichi kn-aut-name=¬“‡Œdˆê kn-aut-sei=¬“‡ kn-aut-mei=Œdˆê aut-affil-num=1 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil=‰ªŽR‘åŠwŠwpŒ¤‹†‰@ˆãŽ•–òŠwˆæ en-keyword=rhodopsin kn-keyword=rhodopsin en-keyword=opsin kn-keyword=opsin en-keyword=retinal kn-keyword=retinal en-keyword=G protein coupled receptor kn-keyword=G protein coupled receptor en-keyword=vision kn-keyword=vision END