Article
Chemistry, Multidisciplinary
Laura Pedraza-Gonzalez, Edoardo Cignoni, Jacopo D'Ascenzi, Lorenzo Cupellini, Benedetta Mennucci
Summary: In response to varying light conditions, light-harvesting complexes (LHCs) undergo conformational changes to protect the photosynthetic organism from excessive light irradiation. Activation of the non-photochemical quenching (NPQ) mechanism is triggered by the acidification of the thylakoid lumen, resulting in a switch from a light-harvesting state to a quenched state. The pH sensitivity of the complex is driven by protonation of specific residues, and the quenching mechanism is controlled by a charge-transfer process controlled by the protein conformation.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Plant Sciences
Emilija Dukic, Peter J. Gollan, Steffen Grebe, Virpi Paakkarinen, Andrei Herdean, Eva-Mari Aro, Cornelia Spetea
Summary: Plants face challenges in coping with changes in light intensity, but they have well-designed mechanisms to acclimate. This study reveals that the thylakoid Cl- channel ClCe plays a role in regulating ATP synthase activity, impacting the phosphorylation of LHCII proteins and state transitions in low light conditions.
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Ying-Qi Wang, Jing-Jing Ye, Hong-Zhiyuan Yang, Da Li, Xiao-Xiang Li, Yong-Kang Wang, Xin-Qiang Zheng, Jian-Hui Ye, Qing-Sheng Li, Yue-Rong Liang, Jian-Liang Lu
Summary: The light-sensitive albino tea plant can gradually recover its photosynthetic pigments, chloroplast ultrastructure, and photosynthesis parameters from pale yellow to green through short-term shading treatment. This is attributed to the proper formation of pigment-protein complexes on the thylakoid membrane, benefiting from increased levels of LHCII subunits, particularly the deficiency of Lhcb1, in the shaded leaves of 'HJY'.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Plant Sciences
Mithun Kumar Rathod, Sreedhar Nellaepalli, Shin-Ichiro Ozawa, Hiroshi Kuroda, Natsumi Kodama, Sandrine Bujaldon, Francis-Andre Wollman, Yuichiro Takahashi
Summary: Chlamydomonas reinhardtii's LHCs play a vital role in the function of photosystems. The protein Alb3.1 plays a key role in the assembly of LHCs, interacting with cpSRP43 and cpSRP54 proteins to form an assembly apparatus for most LHCs in the thylakoid membranes.
PLANT AND CELL PHYSIOLOGY
(2022)
Article
Multidisciplinary Sciences
Dan-Hong Li, Wenda Wang, Cuicui Zhou, Yan Zhang, Songhao Zhao, Yi-Ming Zhou, Rong-Yao Gao, Hai-Dan Yao, Li-Min Fu, Peng Wang, Jian-Ren Shen, Tingyun Kuang, Jian-Ping Zhang
Summary: The light-harvesting complex II (LHCII) of Bryopsis corticulans differs in chlorophyll and carotenoid compositions from that of spinach. Using time-resolved absorption spectroscopy, we investigated the ultrafast excitation dynamics of B-LHCII. Our results showed rapid photogeneration of Chl-Chl charge transfer (CT) species and revealed the transfer of singlet excitation between different chlorophyll and carotenoid molecules. The induction of Chl-Chl CT species by red-light excitation is a common occurrence for LHCIIs in light-harvesting form, as observed in S-LHCII.
Article
Biochemistry & Molecular Biology
Jie Wang, Long-Jiang Yu, Wenda Wang, Qiujing Yan, Tingyun Kuang, Xiaochun Qin, Jian-Ren Shen
Summary: Photosystem I (PSI), a crucial component in photosynthesis, has been structurally analyzed in complex with light-harvesting complex I (LHCI) to reveal the arrangement of proteins, cofactors, and newly identified lipid molecules. The research sheds light on the mechanisms of light-energy harvesting, transfer, and supercomplex assembly.
JOURNAL OF INTEGRATIVE PLANT BIOLOGY
(2021)
Article
Chemistry, Physical
Ruidan Zhu, Meixia Ruan, Hao Li, Xuan Leng, Jiading Zou, Jiayu Wang, Hailong Chen, Zhuan Wang, Yuxiang Weng
Summary: This study reexamines the coherent dynamics of energy transfer processes in LHCII using high-S/N transient grating and two-dimensional electronic spectroscopy. The results reveal that electronic coherence decays completely within 50 fs at room temperature, while vibrational coherences of chlorophyll a dominate over oscillations within 1 ps.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Biology
Asako Ishii, Jianyu Shan, Xin Sheng, Eunchul Kim, Akimasa Watanabe, Makio Yokono, Chiyo Noda, Chihong Song, Kazuyoshi Murata, Zhenfeng Liu, Jun Minagawa, David M. Kramer
Summary: Under low light conditions, Ostreococcus tauri assembles its photosystem I (PSI) supercomplex with light-harvesting complexes I (LHCI) and a prasinophyte-specific light-harvesting complex (Lhcp), expanding its photon-absorbing capacity. The structure of the supercomplex exhibits hybrid features of plant-type and green algal-type PSI supercomplexes. The formation of this supercomplex is likely induced by changes in light intensity through phosphorylation.
Article
Multidisciplinary Sciences
Petra Redekop, Emanuel Sanz-Luque, Yizhong Yuan, Gaelle Villain, Dimitris Petroutsos, Arthur R. Grossman
Summary: In this study, the impact of light intensity, light quality, photosynthetic electron transport, and carbon dioxide on the induction of photoprotective genes was assessed using Chlamydomonas reinhardtii. The results showed that photoprotective genes were induced at low light intensity and were modulated by blue and ultraviolet B radiation. Carbon dioxide levels also strongly controlled the expression of photoprotective genes.
Article
Chemistry, Physical
Eunchul Kim, Hisako Kubota-Kawai, Fumihiro Kawai, Makio Yokono, Jun Minagawa
Summary: By comparing the LHCII trimers from different photosystem supercomplexes, this study found distinct conformational differences depending on the binding location, which may modulate the function of LHCII and affect excitation-energy flow in the photosynthetic supercomplex.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Multidisciplinary
Minjung Son, Raymundo Moya, Alberta Pinnola, Roberto Bassi, Gabriela S. Schlau-Cohen
Summary: Plants utilize photoprotection to dissipate excess energy from the sun in order to prevent the generation of harmful photoproducts. Factors such as array size, pH drop, and the presence of carotenoids influence the level of dissipation, providing separate control mechanisms for photoprotection. Understanding these factors allows for a flexible and tunable response to fluctuations in solar energy.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Plant Sciences
Michela Cecchin, Jooyeon Jeong, Woojae Son, Minjae Kim, Seunghye Park, Luca Zuliani, Stefano Cazzaniga, Andrea Pompa, Chan Young Kang, Sangsu Bae, Matteo Ballottari, EonSeon Jin
Summary: This study generated lpa2 knockout mutants in Chlamydomonas reinhardtii using the CRISPR-Cas9 system and found that the absence of LPA2 protein resulted in impaired PSII assembly and function, leading to compromised photoautotrophic growth.
Article
Plant Sciences
Vasily V. Terentyev
Summary: The study reveals that the mutant cai3 in C. reinhardtii cells exhibits an unusual chloroplast morphology under moderate light, deficiency in CAH3 leads to an increase in PSII photoprotective mechanisms, and a shift in the balance of the PSII damage-repair cycle.
PLANT PHYSIOLOGY AND BIOCHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Yandu Lu, Qinhua Gan, Masakazu Iwai, Alessandro Alboresi, Adrien Burlacot, Oliver Dautermann, Hiroko Takahashi, Thien Crisanto, Gilles Peltier, Tomas Morosinotto, Anastasios Melis, Krishna K. Niyogi
Summary: The study found that LHCR proteins play a key role in red algae, affecting the balance between photoprotection and light harvesting in photosynthesis. The mutant hlr1 shows increased tolerance to high light due to reduced oxidative stress in PSI, limiting oxidative damage and promoting growth. However, under low light conditions, HLR1 deficiency reduces PSI light-harvesting capacity and growth.
NATURE COMMUNICATIONS
(2021)
Article
Plant Sciences
Guangxi Wu, Lin Ma, Cai Yuan, Jiahao Dai, Lai Luo, Roshan Sharma Poudyal, Richard T. Sayre, Choon-Hwan Lee
Summary: In this study, it was found that in dark-adapted rice leaves, the light-harvesting complex II (LHCII) becomes phosphorylated and forms supercomplexes under low light conditions, which transition to aggregates under high light conditions. Knockout mutants of protein phosphatase 1 (PPH1) failed to form these LHCII aggregates, indicating their role in dissipating excess light energy. The aggregation of dephosphorylated LHCII in LHCII-PSI-LHCI supercomplexes was proposed as a newly observed photoprotective process in early HL acclimation in rice plants.
JOURNAL OF EXPERIMENTAL BOTANY
(2021)
Article
Plant Sciences
Xian Jun Zhang, Yuki Fujita, Ryutaro Tokutsu, Jun Minagawa, Shen Ye, Yutaka Shibata
Summary: This study investigates the in vivo reversible changes in intracellular distribution of chlorophyll fluorescence during light-induced state transitions in Chlamydomonas reinhardtii, using a newly developed noninvasive excitation-spectral microscope technique that provides powerful spectral information about excitation-energy transfer between Chl-a and Chl-b.
PLANT AND CELL PHYSIOLOGY
(2021)
Article
Biology
Taro Maeda, Shunichi Takahashi, Takao Yoshida, Shigeru Shimamura, Yoshihiro Takaki, Yukiko Nagai, Atsushi Toyoda, Yutaka Suzuki, Asuka Arimoto, Hisaki Ishii, Nori Satoh, Tomoaki Nishiyama, Mitsuyasu Hasebe, Tadashi Maruyama, Jun Minagawa, Junichi Obokata, Shuji Shigenobu
Summary: Sea slugs that sequester chloroplasts from algae can prolong their lifespan through photosynthesis. Contrary to previous beliefs, it was found that photosynthetic genes are not encoded on the nucleus, and genes related to proteolysis and immunity are up-regulated in chloroplast-enriched tissue without horizontal gene transfer. This study suggests that complex adaptive traits like photosynthesis can be transferred between eukaryotic kingdoms through unique organelle transmission.
Review
Plant Sciences
Xin Sheng, Zhenfeng Liu, Eunchul Kim, Jun Minagawa
Summary: Photosynthesis is the process by which plants and algae capture photons and store their energy through reactions in photosystem II (PSII). Recent studies on the architectures of PSII-LHCII supercomplexes in plants and green algae provide insights into the evolution of these complexes and their energy transfer pathways. The efficiency of photosynthesis largely depends on the initial reactions in PSII, involving light-harvesting and electron transfer mechanisms.
PLANT AND CELL PHYSIOLOGY
(2021)
Editorial Material
Plant Sciences
Thomas Roach, Eunchul Kim, Lijin Tian, Bernard Lepetit
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Chemistry, Physical
Eunchul Kim, Hisako Kubota-Kawai, Fumihiro Kawai, Makio Yokono, Jun Minagawa
Summary: By comparing the LHCII trimers from different photosystem supercomplexes, this study found distinct conformational differences depending on the binding location, which may modulate the function of LHCII and affect excitation-energy flow in the photosynthetic supercomplex.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Astronomy & Astrophysics
Yu Komatsu, Yasunori Hori, Masayuki Kuzuhara, Makiko Kosugi, Kenji Takizawa, Norio Narita, Masashi Omiya, Eunchul Kim, Nobuhiko Kusakabe, Victoria Meadows, Motohide Tamura
Summary: Remote sensing has shown that photosynthesis can be traced through vegetation red edge (VRE) and solar-induced fluorescence. This study examines the detectability of biological fluorescence from chlorophylls (Chls) and bacteriochlorophylls (BChls) on Earthlike planets with different atmospheres around Sun and M dwarfs. The presence of atmospheric absorption and VRE obscures the fluorescence emissions from Chls and BChls. In the absence of water cloud coverage or strong absorbers near 1000 nm, BChl-based fluorescence could be a suitable biosignature. However, the Chl fluorescence is weaker due to spectral blending with the VRE.
ASTROPHYSICAL JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Kiyofumi Takaba, Saori Maki-Yonekura, Ichiro Inoue, Kensuke Tono, Tasuku Hamaguchi, Keisuke Kawakami, Hisashi Naitow, Tetsuya Ishikawa, Makina Yabashi, Koji Yonekura
Summary: The structure analysis of small crystals is vital in various fields, including synthetic organic chemistry, pharmaceutical and material sciences, where large crystals cannot be obtained. In this study, the structure of an organic molecule, rhodamine6G, was characterized in detail using an X-ray free-electron laser (XFEL) with a resolution of 0.82 A. A direct comparison between the XFEL and electron crystallography methods revealed that both techniques can accurately determine the position of some hydrogen atoms based on the type of chemical bond involved. The variations in distances measured by XFEL and electron diffraction were attributed to the expected differences in X-ray and electron scatterings.
Article
Plant Sciences
Eunchul Kim, Makio Yokono, Kazuo Tsugane, Asako Ishii, Chiyo Noda, Jun Minagawa
Summary: In green plants, photosystem I (PSI) and photosystem II (PSII) bind to their respective light-harvesting complexes to form supercomplexes. These supercomplexes further form megacomplexes, however, this is not observed in the green alga Chlamydomonas reinhardtii. The stable rice PSI-PSII megacomplex exhibits energy transfer capabilities, indicating species diversity in the formation and stability of photosystem megacomplexes.
PLANT AND CELL PHYSIOLOGY
(2023)
Article
Multidisciplinary Sciences
Ryo Nagao, Koji Kato, Tasuku Hamaguchi, Yoshifumi Ueno, Naoki Tsuboshita, Shota Shimizu, Miyu Furutani, Shigeki Ehira, Yoshiki Nakajima, Keisuke Kawakami, Takehiro Suzuki, Naoshi Dohmae, Seiji Akimoto, Koji Yonekura, Jian-Ren Shen
Summary: By using cryo-EM, the authors determined the structure of a PSI monomer associated with six IsiA proteins in Anabaena, providing insights into the diversity and functions of IsiAs. IsiAs are expressed in cyanobacteria under iron-deficient conditions, and the binding properties and functional roles of IsiAs in PSI were still unknown in Anabaena. The cryo-EM structure of a PSI-IsiA supercomplex isolated from iron-deficient Anabaena revealed the association of six IsiA subunits with a PSI core monomer, and the absence of a PsaL subunit due to the occupation of its position by the C-terminal domain of IsiA2.
NATURE COMMUNICATIONS
(2023)
Article
Biology
Asako Ishii, Jianyu Shan, Xin Sheng, Eunchul Kim, Akimasa Watanabe, Makio Yokono, Chiyo Noda, Chihong Song, Kazuyoshi Murata, Zhenfeng Liu, Jun Minagawa, David M. Kramer
Summary: Under low light conditions, Ostreococcus tauri assembles its photosystem I (PSI) supercomplex with light-harvesting complexes I (LHCI) and a prasinophyte-specific light-harvesting complex (Lhcp), expanding its photon-absorbing capacity. The structure of the supercomplex exhibits hybrid features of plant-type and green algal-type PSI supercomplexes. The formation of this supercomplex is likely induced by changes in light intensity through phosphorylation.
Article
Chemistry, Multidisciplinary
Saori Maki-Yonekura, Keisuke Kawakami, Kiyofumi Takaba, Tasuku Hamaguchi, Koji Yonekura
Summary: High resolution X-ray crystallography is limited to samples with superb crystallinity, but a sub-1.2 angstrom resolution cold field emission single-particle cryo-EM structure of apoferritin allows for the visualization of hydrogen atoms, their charges, and chemical bonding. These observations are important for understanding the stabilization and function of protein structures. The positioning and properties of hydrogen densities were validated by various techniques.
COMMUNICATIONS CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Christoph Gerle, Yuko Misumi, Akihiro Kawamoto, Hideaki Tanaka, Hisako Kubota-Kawai, Ryutaro Tokutsu, Eunchul Kim, Dror Chorev, Kazuhiro Abe, Carol V. Robinson, Kaoru Mitsuoka, Jun Minagawa, Genji Kurisu
Summary: Three structures of the PSI-LHCI supercomplex from Chlamydomonas reinhardtii were investigated using X-ray crystallography and single particle cryo-EM. The absence of six chlorophylls from the luminal side of the LHCI belts was observed in the X-ray structure, suggesting their potential influence on excitation transfer. Cryo-EM revealed additional densities on both sides of the supercomplex, which disappeared after the binding of oxidized ferredoxin. Based on these structures, a resting state PSI-LHCI supercomplex with reduced chlorophyll content and specific binding partners was proposed.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2023)
Article
Biochemistry & Molecular Biology
Sam Wilson, Eunchul Kim, Asako Ishii, Alexander Ruban, Jun Minagawa
Summary: The overexpression of photoprotective proteins in the det1-2 phot mutant of green algae enhances the nonphotochemical quenching (NPQ) response, allowing the mutant to grow and survive under high light intensities that are lethal for wild-type cells. This mutant exhibits a smaller PSII cross-section and a detachment of LHCII antenna in the NPQ state. The study reveals the mechanism by which the overexpression of photoprotective proteins enables an efficient and effective photoprotective response in the det1-2 phot mutant.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY
(2023)
Meeting Abstract
Biophysics
Eunchul Kim, Hisako Kubota-Kawai, Fumihiro Kawai, Makio Yokono, Jun Minagawa
BIOPHYSICAL JOURNAL
(2023)
Article
Plant Sciences
Xiaowei Pan, Ryutaro Tokutsu, Anjie Li, Kenji Takizawa, Chihong Song, Kazuyoshi Murata, Tomohito Yamasaki, Zhenfeng Liu, Jun Minagawa, Mei Li
Summary: The study provides high-resolution structures of the PSI-LHCI-LHCII supercomplex from Chlamydomonas reinhardtii, elucidating the assembly mechanism between the PSI-LHCI complex and phosphorylated LHCII trimers, as well as the direct interactions between specific LhcbM isoforms and the PSI core. Functional studies on mutant strains lacking LhcbM1 or LhcbM5 demonstrate that only LhcbM5 is essential for supercomplex formation, revealing specific interactions and potential energy transfer pathways between green algal PSI and phosphorylated LHCIIs.
